Montgomery County
400 Bridge Street, Suite 2
Red Oak, IA 51566-1402
712-623-2592
FAX 712-623-2594
E-mail: drey@iastate.edu
HORTICULTURE
NEWSLETTER
DATE: January 2012
Bill Drey
Bill Drey
Montgomery County Extension Program Coordinator
PLANNING MEETING
The Red Oak Garden Club members and Master Gardeners will meet on January 30 th at the
Montgomery County Extension Office.
We will be planning activities and meetings for the year. We will be having a program each
month for anyone interested.
MONDAY
JANUARY 30, 2012
7:00 P.M.
Montgomery County Extension Office
We will also have a short program.
Everyone is welcome. If you have ideas or suggestions, please let Bill Drey know.
YARD AND GARDEN
Iowa State University Extension horticulture specialists offer tips and information for you.
To have questions answered, contact the Montgomery County Extension Office or experts at
hortline@iastate.edu or call 515-294-3108.
By: RICHARD JAURON
How do you root the top of a pineapple?
Cut off the top of the pineapple about 1 inch below the cluster of leaves. Trim away the outer portion
of the pineapple top, leaving the tough, stringy core attached to the leaves. Also, remove a few of the
lowest leaves. The pineapple top then should be allowed to dry for several days. The drying period
allows the moist core tissue to dry and discourages rotting. After drying, insert the pineapple top into
perlite, vermiculite or coarse sand up to the base of its leaves. Water the rooting medium. Keep the
rooting medium moist, but not wet, during the rooting period. Finally, place the pineapple top in bright,
indirect light. Rooting should occur in six to eight weeks.
When the pineapple has developed a good root system, carefully remove it from the rooting medium.
Plant the rooted pineapple in a light, well-drained potting mix. Water well. Then place the plant in bright,
indirect light for three to four weeks.
After three to four weeks, the plant can be placed in a sunny window. Keep the potting soil moist with
regular watering. Using a soluble houseplant fertilizer, fertilize the pineapple once or twice a month in
spring and summer. Fertilization usually isn’t necessary in fall and winter. The plant can go outdoors in
late May, but must come back indoors before the first fall frost.
How do you sprout an avocado seed?
To sprout the seed, remove it from the center of the fruit and wash in water. For propagation
purposes, the broad end of the seed is regarded as the bottom. The pointed end is the top. Insert three
or four toothpicks into the sides of the seed. They should be placed about halfway up the seed. Then
suspend the seed over a glass of water. The bottom one-fourth of the seed should rest in water. The
seed should sprout within a few weeks. During this time, periodically add water to maintain the initial
water level. If the seed doesn’t sprout within two months, discard it and begin another. The roots are
usually the first to emerge from the seed. The stem appears later. Pot the seedling when the root system
has become well developed; the roots are approximately 2 to 3 inches long.
Remove the toothpicks and plant into a 6- to 8-inch-diameter pot using a commercial potting mix.
Position the seed in the center of the pot. The top of the seed should be level with the soil surface. After
potting, water thoroughly, then place the plant in a brightly lit location. A site near an east or west window
is ideal. Water the plant on a regular basis. Keep the potting soil moist, but not wet. To encourage
branching, pinch out the growing point when the avocado seedling is approximately 12 inches tall.
Fertilize once or twice a month in spring and summer with a soluble houseplant fertilizer.
Can I germinate the seeds from a grapefruit?
Seeds of grapefruit, oranges and lemons can be germinated indoors. After removing the seeds from
the fruits, plant the seeds in a pot containing potting soil. Plant the seeds about 1 inch deep. After
planting, moisten the potting soil. Keep the potting soil moist until the seeds germinate. Germination may
occur within two to three weeks or take as long as six to eight weeks. After the seedlings emerge, place
the plants in a sunny window. Grapefruit, orange and lemon trees can be grown as houseplants for a few
years. Eventually, however, they get too big for indoors and will need to be discarded. Plants grown from
seeds seldom produce fruit indoors.
What would be a good location for African violets in the home?
Place African violets in a location that receives bright, indirect light. A site near an east or north
window is often a good location (do not place African violets in direct sun). If a suitable window isn’t
available, place African violets under a fluorescent light fixture containing two 40-watt fluorescent tubes.
Suspend the fixture eight to 12 inches above the plants and leave the lights on for 12 to 16 hours per
day. The ideal temperature range for African violets is 60 to 80 degrees Fahrenheit. In winter, keep
African violets away from cold drafts and heat sources.
How much light does an African violet need?
African violets need the proper amount of light to grow and bloom well. Plants that receive insufficient
levels of light have thin, blue-green leaves with long petioles. They also don’t bloom well. Plants that
receive too much light are stunted and produce small, crinkled, yellow leaves borne on short petioles.
Generally, sites near north or east windows are best for African violets. However, if these sites are not
available, African violets can be successfully grown under fluorescent lights. A fluorescent light fixture
suspended eight to 12 inches above the plants and left on for 12 to 16 hours per day should provide
sufficient light for African violets.
My African violets aren’t blooming well. Why?
The African violets may not be receiving adequate light. The proper amount of light is essential for
good bloom - whether that is natural light or under flourescent lights as described above.
Excessive fertilization could also be responsible for the poor bloom. African violets need to be
fertilized to promote bloom. However, excessive fertilization leads to vigorous vegetative growth and poor
flowering. Using a complete, water soluble fertilizer, apply a dilute fertilizer solution once every two
weeks in spring, summer and fall. Fertilization usually isn’t necessary during the winter months.
The lower leaves on my African violet have turned yellow and become droopy. What could be
wrong?
The symptoms suggest the African violet may have root rot. Root rot symptoms initially develop on
the lower leaves. The lower leaves turn yellow and droop. As the root rot progresses, affected leaves
turn brown and become mushy. Over time, the symptoms spread upward. Plants may eventually die if
growing conditions are poor and no corrective actions are taken.
Root rots are usually caused by overwatering. African violets prefer an evenly moist soil. They don’t
like wet or dry potting soils. In wet situations, root rot fungi gradually destroy the African violet’s roots,
causing the plant to decline. Prevention is the best defense against root rot. Allow the soil surface to dry
to the touch before watering African violets. Also, select a light, well-drained potting mix when potting or
repotting African violets.
Dust and grease accumulate on my houseplants. How should they be cleaned?
Dust and grease often accumulate on the leaves of houseplants. The dust and grease not only make
them unattractive, it may slow plant growth. Cleaning houseplants improves their appearance, stimulates
growth and may help control insects and mites.
Large, firm-leafed plants may be cleaned with a soft sponge or cloth. Wash the foliage using a very
dilute solution of dishwashing soap and tepid water. Another method is to place the plants in the shower
and give them a good bath. Be sure to adjust the water temperature before placing the plants under the
shower head.
The leaves on my houseplant are covered with a black, sooty material. What is it and is it harming
the plant?
The black, sooty material is likely sooty mold. Sooty mold is caused by several different fungi. The
fungi don’t infect plants, but grow on the sugary substance (honeydew) excreted by scales, mealy bugs,
whiteflies and other sap-sucking insects.
Sooty mold causes little harm to houseplants. The damage is mainly aesthetic. The black, sootcovered leaves aren’t very attractive. However, the sap-sucking insects may seriously harm houseplants.
Scales, mealy bugs and whiteflies are very difficult to control. Discard the pest-infested plant or follow
recommended control measures. Control efforts will require patience and persistence.
There are some white blotches on my African violet leaves. What are they and how can the
problem be controlled?
The white material on the foliage of your African violet is probably powdery mildew. Powdery mildew
is a fungal disease that is common on indoor plants, such as African violets, begonias and poinsettias.
Outbreaks of powdery mildew on houseplants typically occur in winter or early spring. High relative
humidity and poor air circulation favor powdery mildew development on houseplants.
If only a few leaves have powdery mildew, pinch them off and discard them to keep the fungus from
spreading. Humidity levels can be lowered by increasing the spacing between plants. Moving plants out
of rooms with high humidity (kitchens and bathrooms) is another option. While fungicides are available
for use against powdery mildew, cultural controls are the preferable way to control powdery mildew on
plants in the home. Severely infected plants may need to be discarded.
The leaves on my houseplant are covered with a sticky sap. There are also small “bumps” on the
stems. What is the problem?
The houseplant may be infested with scale insects. These small, inconspicuous insects are covered
with shell-like coverings. They attach themselves to stems or leaves, and suck sap from the plants. As
they feed, the scale insects excrete a sweet, sticky substance called honeydew. The honeydew
accumulates on the plant’s lower foliage, furniture, carpeting or other objects beneath the infested plant.
The life cycle of scale insects consists of the egg, nymph, and adult stages. Eggs are laid below the
scale coverings of the adult females. When the eggs hatch, the nymphs crawl from underneath their
mother’s scale and move a short distance to their own feeding site. The newly emerged nymphs are also
called crawlers. At their new location, the nymphs insert their slender stylets (mouthparts) into the plant
and begin sucking sap. The covering or shell develops soon after feeding begins. The scale insects
remain at these feeding sites the rest of their lives.
A small scale infestation causes little harm to healthy houseplants. However, a heavy scale
infestation may result in poor, stunted growth. In severe cases, death of infested plants is possible.
How can I determine if my houseplant has spider mites?
Spider mites are tiny (about 1/50 inch long when mature). As a result, they are difficult to see with
the naked eye. A convenient detection technique is to hold a sheet of white paper under a stem and then
shake or tap the stem against the paper. The mites, if present, will show up as tiny, slow-moving specks
on the paper. Examination of an infested plant may reveal very fine webbing produced by the mites.
Also, check the plant for symptoms of mite feeding. In light infestations, plant foliage will appear to be
speckled with tiny tan spots. Heavy mite infestations can turn the foliage to greenish yellow and
eventually tan or brown. Heavily infested plants often drop their leaves.
How do I control spider mites on my houseplant?
If the mite infestation is light, spraying infested plants with water should help reduce the mite
population. Move infested plants into the bathtub or shower and forcefully spray the plants with water to
dislodge the mites. Several miticides (pesticides that control mites) are available for houseplants. Check
for products at your local garden center. Sprays available to home gardeners usually contain insecticidal
soap, horticulture oil or pyrethrin. When using miticides, carefully read and follow label instructions.
Thorough spraying, especially to the undersides of the leaves, is important for control. These sprays
have no residual activity and only control mites that are contacted directly. Repeated applications will be
necessary. Also, keep plants watered and fertilized to promote plant vigor and reduce the impact of mite
feeding.
It’s often best to discard houseplants that are heavily infested with mites. Control efforts will likely
be ineffective and the mites could spread to other indoor plants.
I have small, white, cotton-like clumps on my houseplant. What are they?
The small, white, cotton-like clumps on your houseplant are probably mealybugs. The body of
each mealybug is oval and about one-fourth inch long. However, the soft, segmented body is concealed
by filaments of white wax that cover the insect. The filaments extend out from the periphery of the body
and may be up to one-half inch long.
Mealybugs have needle-like sucking mouthparts. They insert their needle-like beaks into plants
and suck sap from the plant tissue. As they feed, mealybugs excrete a sweet, sticky liquid called
honeydew. The honeydew accumulates on the lower leaves of the plant, table or floor.
Mealybugs lay eggs in a compact, white, waxy sac, usually in the area between the leaf stalk
(petiole) and stem. Three hundred or more yellowish or orange eggs may be deposited by a single
female. The eggs hatch into tiny, immature mealybugs called nymphs that move about on the plant
searching for a place to settle and eventually insert their beaks into the plant and begin sucking sap.
As mealybugs feed, numerous waxy filaments start forming as white, thread-like projections
located along the edge of the body. The filaments grow, curl and tangle until the entire body is covered.
Mealybugs usually remain in one place for their entire life span of four to 10 weeks.
How do I control mealybugs on a houseplant?
Mealybugs on houseplants are difficult to control. Unless the plant is particularly valuable, it may
be best to throw away the infested plant before the insects spread to other houseplants. The standard
remedies for houseplant pests can be successful if applied with diligence and persistence. Picking off
individual mealybugs and egg sacs or dabbing each one with an alcohol-soaked cotton swab may be
satisfactory for lightly-infested plants. Similarly, syringing the plants with a forceful spray of lukewarm
water may dislodge a light mealybug infestation.
Mealybugs also can be controlled with insecticide sprays. Use aerosol or hand pump spray
products made just for houseplants. These products may contain any of several different ingredients,
including insecticidal soaps, pyrethrin, neem or a synthetic pyrethroid, such as permethrin, bifenthrin or
resmethrin. Granular insecticides that you apply to the soil of infested houseplants also may be effective.
Use with caution and read and follow all label directions.
In most cases, houseplants that are heavily infested with mealybugs should be discarded. Control
will be extremely difficult (if not impossible).
How do I control scale on a houseplant?
Scale insects are difficult to control. Systemic insecticides are generally ineffective. The shell-like
covering protects the scale from contact insecticides. The only time scale insects are vulnerable to
contact insecticides is during the crawler stage. Since scale insects on houseplants don’t reproduce at a
specific time, scale-infested plants need to be sprayed with insecticidal soap or other houseplant
insecticide every seven to 10 days until the infestation is eliminated. Small infestations can be controlled
by individually scraping off the scales or by dabbing each scale with an alcohol-soaked cotton swab. It’s
often best to discard houseplants that are heavily infested with scale as control is nearly impossible and
the insects could spread to other houseplants.
Can hollies be successfully grown in Iowa?
American holly (Ilex opaca) and English holly (Ilex aquifolium) are prized for their glossy, green
leaves and brightly colored fruit. Sprigs of both hollies are often used in wreaths, centerpieces and other
Christmas decorations. Unfortunately, American and English hollies are not reliably hardy in Iowa.
However, winterberry (Ilex verticillata) and Meserve hybrid hollies (Ilex x meserveae) can be successfully
grown in the state.
Hollies are dioecious. Dioecious plant species produce male and female flowers on separate plants.
Only female holly plants produce the red, berry-like fruit. However, a male plant is required for pollination
and fruit set.
While most hollies are evergreen, winterberry is deciduous (loses all of its leaves in fall). Winterberry
grows 6 to 10 feet tall. The fruit on female plants turn bright red in fall and persist into winter. (Birds
usually devour the fruit by mid-winter.) Excellent fruiting varieties include ‘Sparkleberry,’ ‘Winter Red,’
‘Afterglow’ and ‘Red Sprite.’ ‘Jim Dandy’ is a good pollinator for ‘Afterglow’ and ‘Red Sprite.’ ‘Southern
Gentleman’ pollinates ‘Winter Red’ and ‘Sparkleberry.’ Winterberry performs best in moist, acidic soils.
Plants can be grown in partial shade to full sun. Best fruiting occurs in those areas that receive at least
six hours of sun.
Meserve hybrid hollies are evergreens. ‘Blue Prince,’ ‘Blue Princess,’ ‘Blue Boy’ and ‘Blue Girl’ have
dark, bluish green foliage and are often referred to as blue hollies. The female varieties have colorful red
fruit. Other attractive Meserve hybrids include China Boy® and China Girl®. Meserve hollies are variable
in height. Most varieties grow 5 to 10 feet tall. They are hardy to -20 F (USDA Hardiness Zone 5). In
Iowa, Meserve hollies perform best in the southern half of the state. Meserve hollies are susceptible to
desiccation injury from the sun and dry winds in winter. When selecting a planting site, choose a
protected location, such as on the east side of a building.
What are the advantages and disadvantages of dwarf and semi-dwarf fruit trees?
Dwarf and semi-dwarf fruit trees are produced by grafting or budding the desired variety onto a
dwarfing rootstock. Most standard-size fruit trees eventually get 25 to 30 feet tall. Dwarf and semi-dwarf
fruit trees are much smaller. Fruit trees grown on dwarfing rootstocks typically grow 10 to 15 feet tall.
Dwarf and semi-dwarf fruit trees are easier to maintain (prune, spray, harvest, etc.), fit better into
small home landscapes, and produce fruit sooner after planting than standard-size trees. However, some
dwarf and semi-dwarf fruit trees have poor root anchorage, so they may need to be supported with a
stake or trellis.
What is mistletoe?
Mistletoe is a semi-parasitic plant with leathery, evergreen leaves and small, white berries. Mistletoe
plants manufacture their own food, but obtain water and mineral nutrients from a host plant. Host plants
include numerous deciduous and evergreen trees. Mistletoe obtains water and nutrients via root-like
haustoria that grow into the host plant’s water conducting tissue. Mistletoe berries are readily eaten by
birds. The birds digest the pulp of the berries and excrete the seeds. The sticky seeds stick to the
branches of trees. At germination, the mistletoe seedling develops haustoria that grow through the bark
of the tree and into its water conducting tissue.
American mistletoe (Phoradendron leucarpum) can be found growing in deciduous trees from New
Jersey and southern Indiana southward to Florida and Texas. (Phoradendron is derived from Greek and
literally means “thief of the tree.”) It is the state floral emblem of Oklahoma. Mistletoe sold during the
holiday season is gathered in the wild. Most mistletoe is harvested in Oklahoma and Texas.
Traditions involving mistletoe date back to ancient times. Druids believed that mistletoe could bestow
health and good luck. Welsh farmers associated mistletoe with fertility. A good mistletoe crop foretold a
good crop the following season. Mistletoe was also thought to influence human fertility and was
prescribed to individuals who had problems bearing children. It has been used in medicine, as treatment
for pleurisy, gout, epilepsy, rabies and poisoning. In addition, mistletoe played a role in a superstition
concerning marriage. It was believed that kissing under the mistletoe increased the possibility of
marriage in the upcoming year. Today, kissing under the mistletoe is a sign of goodwill, friendship or
love.
Mistletoe should be kept out of the reach of small children and family pets, as the berries are
poisonous.
Can you give me a brief history of the poinsettia?
The poinsettia (Euphorbia pulcherrima) is native to Mexico. In Mexico, the poinsettia is a large shrub
or small tree that may reach a height of 10 to 15 feet.
Poinsettias were cultivated by the Aztecs, who called the plant Cuetlaxochitl. They used the colorful
bracts to make a reddish purple dye. The poinsettia’s milky sap was used to treat fevers.
After the Spanish conquest and the introduction of Christianity, poinsettias began to be used in
Christian ceremonies. Franciscan priests used the poinsettia in their nativity processions.
Poinsettias were first introduced into the United States by Joel Roberts Poinsett, the United States
Minister (ambassador) to Mexico from 1825 to 1829. Poinsett had plants sent to his home in Greenville,
S.C. He then distributed plants to botanical gardens and horticultural friends, including John Bartram of
Philadelphia.
The popularity of the poinsettia as a holiday plant grew rapidly in the latter half of the 20th century
with the development of shorter, free-branching, longer-lived cultivars. Plant breeders also expanded the
color range of the poinsettia. Poinsettias are now available in red, pink, white and gold. Variegated and
marbled poinsettias also are available. Today, the poinsettia is the number one flowering potted plant in
the United States.
Deicing Salts and the Home Landscape
Snow and ice are headaches for motorists and pedestrians. To prevent accidents on slippery surfaces,
deicing compounds are used by highway departments, businesses, and homeowners to melt ice and snow on
roadways, parking lots, sidewalks, and driveways. While deicing materials improve travel conditions, they can
damage automobiles, concrete surfaces, and landscape plants.
Deicing Materials
Most deicing materials are salts that melt ice and snow by lowering the freezing point of water below 32
degrees Fahrenheit. Commonly used deicing salts include sodium chloride (NaCl), calcium chloride (CaCl2),
potassium chloride (KCl), and magnesium chloride (MgCl2).
Abrasive materials, such as sand, do not melt ice or snow. However, they improve traction on snow and
ice-covered surfaces.
Effects of Deicing Salts
Deicing salts can damage landscape plants when excessive amounts accumulate in the soil. The most
serious damage typically occurs near major streets and highways where salt from run-off accumulates in the
nearby soil. Excessive use of salt by homeowners can also create problems. Trees, shrubs, perennials, and
turfgrasses are susceptible to salt damage. Additionally, spray from passing vehicles can damage roadside plants,
particularly evergreens.
Salts affect plant growth in several ways. When high levels of salt are present in the soil, plants are
unable to absorb sufficient water even though soil moisture is plentiful. Plants suffer a salt-induced water shortage
termed "physiological drought." High levels of salt restrict the uptake of essential nutrients by plant
roots. Excessive amounts of sodium and chloride ions in plant tissue are toxic to many plants. Soil structure is
damaged by high levels of sodium. Salt deposited directly on plant foliage can cause dehydration of plant tissue.
The symptoms of salt injury to deciduous trees and shrubs include stunted growth, marginal leaf scorch,
early fall coloration, and twig dieback. Accumulation of salt in the soil over several years may result in progressive
decline and eventual death.
Salt damage to evergreens results in yellowing or browning of the needles and twig dieback. Evergreens
near heavily salted roadways are often damaged by salt spray. Spray damage is most severe on the side of the
plant nearest the highway.
The severity of plant damage depends upon the type of salt and other factors. Calcium chloride,
potassium chloride, and magnesium chloride are less harmful to plants than sodium chloride. The degree of salt
damage also depends upon the amount of salt applied, soil type, amount of rainfall, direction of run-off, and
prevailing winds. The condition and type of plant material is also important. Healthy, vigorous plants are more
tolerant of salt than poorly growing specimens. Bur oak, northern red oak, honeylocust, northern catalpa, Kentucky
coffee tree, horse chestnut, mugo pine, and eastern red-cedar are tolerant of soil-borne salt, while sugar maple,
American linden, Canadian hemlock, and eastern white pine are sensitive to soil salt.
Salt Injury Prevention
Homeowners can minimize salt damage by using deicing salts prudently. Before applying salt, wait until
the precipitation has ended and remove as much of the ice and snow as possible. Use deicing salts at rates
sufficient to loosen ice and snow from driveways and sidewalks, then remove the loosened ice and snow with a
shovel. (Deicing salts need to be applied at much higher rates to completely melt ice and snow.) Mix salt with
abrasive materials, such as sand or kitty litter. Fifty pounds of sand mixed with one pound of salt works
effectively. Avoid piling salt-laden snow and ice around trees and shrubs. While the amount of salt applied to major
roadways can not be controlled, steps can be taken to minimize damage. As soon as the ground thaws in early
spring, heavily water areas where salt accumulates over winter. A thorough soaking should help flush the salt from
the root zone of plants. If possible, alter the drainage pattern so winter run-off drains away from ornamental
plants. When planting trees near major streets or highways, select salt tolerant tree species.
Deicing salts are both good and bad. Judicious use of deicing salts helps insure safe travel conditions for
pedestrians and motorists and minimizes damage to landscape plants and the environment.
By Richard Jauron, Department of Horticulture
Dry Soil Conditions Increase the Risk for Winter Root
Injury on Fruit Crops and Other Perennial Plants
The root systems of perennial plants are much less cold tolerant that the above ground portions of the
plants. For the most species we can grow in Iowa, root injury can begin occur when the soil temperature drops
below 18 to 15 degrees F. Fortunately, the soil has a tremendous buffering capacity and the temperature in the
root zone seldom drops this low, but it can when there is a shortage of soil moisture going into the winter.
Soil moisture is important for the transfer of heat energy in the soil. During the growing season, the soil
temperature near the surface is warmer than at the lower depths, and the net movement of energy is from the
surface to the lower depths. A moist soil will conduct greater energy downward than a dry soil because much of
the pore space between particles is occupied by air and air is a very poor conductor of energy. Also, because of
the lack of moisture holding capacity, sandy soils conduct less energy than loamy soils.
During the winter, the soil temperature at the lower depths is warmer that near the surface and the net
movement of energy is from the lower depths of the soil to the surface where it escapes to the atmosphere. Again,
a moist soil will conduct greater energy upward than a dry soil and temperature of the moist soil will be warmer
near the surface than the dry soil. If there is snow cover or mulch on the soil surface, it will trap the energy, and the
temperature of the soil near the surface will be warmer than an exposed soil.
Therefore, if we continue to go into the winter with a shortage of soil moisture, the potential for winter injury
to the roots will remain high. However, for injury to occur, the dry soil conditions would have to be coupled with the
lack of snow cover and an extended period of sub-freezing temperatures. So besides hoping for snow cover and a
mild winter, measures that can be taken to reduce the risk of winter root injury would include:

Irrigating before the ground freezes.

Applying a mulch to minimize heat loss from the soil. When applying mulch under trees, some
space should be left between the trunk and mulch to reduce the risk of vole damage.

Taking measures to aid in trapping snow - allowing the grass to remain tall, installing snow fencing
at intervals in the field.
By Paul Domoto, Department of
Horticulture
Forcing Amaryllis and Paperwhite Narcissus Indoors
Forcing flower bulbs indoors is an excellent way to brighten the cold, gray days of winter. Two of
the easiest bulbs to force indoors are the amaryllis and paperwhite narcissus (daffodil).
Amaryllis
Amaryllis bulbs can be purchased pre-planted in pots or unpotted. When purchasing unpotted
amaryllis bulbs select large, solid bulbs. The largest bulbs often produce 2 flower stalks. Gardeners can
choose from single-flowering, double-flowering, and miniature varieties. Flower colors include red, pink,
orange, salmon, white, and bicolors.
When planting an amaryllis bulb, select a pot which is approximately 1 to 2 inches wider than the
diameter of the bulb. The container may be clay, ceramic or plastic, but should have drainage holes in
the bottom. Plant the bulb in a well-drained potting soil. Add a small amount of potting soil in the bottom
of the pot. Center the bulb in the middle of the pot. Then add additional potting soil, firming it around the
roots and bulb. When finished potting, the upper one-half of the bulb should remain above the soil
surface. Also, leave about one inch between the soil surface and the pot's rim. Then water well and place
in a warm (70 to 75 degree Fahrenheit) location.
Check the pot before watering a pre-planted amaryllis bulb. If the container doesn't have drainage
holes, remove the bulb and replant it in a pot with drainage holes. Water well.
After the initial watering, allow the soil to dry somewhat before watering again. Keep the soil moist,
but not wet. When growth appears, move the plant to a sunny window and apply a water-soluble fertilizer
ever 2 to 4 weeks.
During flower stalk elongation, turn the pot each day to keep the flower stalk growing
straight. Flower stalks that lean badly will need to be staked.
Flowering usually occurs about 6 to 8 weeks after potting. When the amaryllis begins to bloom,
move the plant to a slightly cooler (65 to 70 degree Fahrenheit) location that doesn't receive direct sun to
prolong the life of the flowers.
Some individuals discard their amaryllis after it is done blooming. However, if given proper care, it
is possible to save the amaryllis and force it to flower again next winter.
Paperwhite Narcissus
Paperwhite narcissus produce clusters of small white, yellow, or orange flowers on 12- to 18inch-tall stems. The flowers of most varieties produce a moderate to strong musky fragrance. Paperwhite
narcissus bulbs can be forced in clear, shallow bowls (no drainage holes) or pots.
When forcing paperwhite narcissus in bowls, partially fill the container with washed gravel or
stones. Place the bulbs on the gravel or stones. Then place additional gravel or stones around the bulbs,
leaving the tips (noses) of the bulbs exposed. Add water to the bowl until it touches the bottom of the
bulbs. Maintain the water at this level throughout the forcing period.
When forcing paperwhites in pots, partially fill the container with potting soil. Place the bulbs on the
soil surface. Then add additional potting soil. When potted, the tips of the bulbs should stick above the
potting soil. Water the potting soil thoroughly. Keep the potting soil moist throughout the forcing period.
Place the planted bulbs in a cool (50 to 55 degree Fahrenheit), dark location for 1 to 2 weeks to
encourage root growth. When the shoots reach a height of 3 inches, move the plants to a sunny window
with a temperature of 60 to 70 degrees Fahrenheit. As the plants continue to grow, staking is often
necessary as the plants are rather floppy. Flowering typically occurs 3 to 6 weeks after potting. When the
paperwhites begin to flower, move the plants from direct sunlight to prolong their bloom period.
Paperwhite narcissus bulbs should be discarded after flowering. Paperwhites cannot be
successfully forced again and are not winter hardy outdoors.
By Richard Jauron, Department of Horticulture
Care of Houseplants during the Winter Months
By Richard Jauron, Department of Horticulture
Growing conditions for houseplants are less than ideal during the winter months. Short days and
long nights, low relative humidities, and cold drafts can be stressful to many houseplants. Good
consistent care, however, should keep them healthy and attractive.
Relative Humidity
Many houseplants prefer a relative humidity of 40 to 50 percent. Unfortunately, the humidity level in
many homes during the winter months may be only 10 to 20 percent. Humidifiers are an excellent way to
increase the relative humidity in the home. Simple cultural practices can also increase the relative
humidity around houseplants. Grouping plants together is an easy way to raise humidity levels. The
water evaporating from the potting soil, plus water lost through the plant foliage, will increase the relative
humidity in the vicinity of the houseplants. Another method is to place houseplants on trays (saucers)
filled with pea gravel or pebbles. Add water to the trays, but keep the bottoms of the pots above the
water line. The evaporation of water from the trays increases the relative humidity.
Misting houseplants is not an effective way to raise the relative humidity. The plant foliage dries quickly
after misting. Misting would have to be done several times a day to be effective and is simply not
practical.
Lighting
To compensate for the short days and long nights of winter, move houseplants closer to windows.
However, make sure the houseplant foliage doesn't actually touch the cold window. Supplemental
lighting is another option. Light units containing special grow lights can be purchased from mailorder
companies or at garden centers. Gardeners can also build their own lighting structure. A standard
fluorescent unit containing one cool white 40 watt tube and one warm white 40 watt tube provides
adequate light for houseplants. Plants should be placed within 6 to 12 inches of the lights.
Watering
In general, houseplants require less frequent watering during the winter months than in spring
and summer. As always when watering houseplants, water thoroughly. Water should drain out the
bottoms of the pots. If the water drains into a saucer, discard the excess.
The plant species, composition of the potting soil, and environmental conditions in the home, determine
watering frequency. Ferns prefer an evenly moist soil and should be watered relatively frequently. Cacti
and succulents, on the other hand, should not be watered until the potting soil is completely dry. The
majority of houseplants fall between these two groups. Most houseplants should be watered when the
soil surface becomes dry to the touch.
Fertilization
Fertilization is generally not necessary during the winter months as most houseplants are growing
very little or resting. Resume fertilization in March or April as growing conditions improve and plants
begin to grow more actively.
Temperatures
Temperatures of 55 to 70 degrees Fahrenheit are adequate for most houseplants. During the
winter months, keep houseplants away from cold drafts, radiators, and hot air vents.
Winter can be a difficult time for houseplants. However, problems can be minimized by providing them
with good consistent care.
Disease Control For Next Year: Start Now!
It's not too late to give your garden some TLC! Many of us forget about gardening as soon as
temperatures drop and leaves fall off trees, but a good end-of-season clean up can save a lot of
headaches next year. Many disease-causing organisms like fungi and bacteria overwinter in dead plants
and diseased leaves. This is why pulling out dead plants and raking leaves in fall is a great way of
reducing common garden diseases on veggies, ornamentals, and shade trees the following season.
Good fall sanitation practices include removing dead plants, leaves, and pruning diseased
plants or trees. Make sure all plant remains are destroyed (by burying or tilling) or removed from the
garden, especially if diseases were present this year.
Sanitation tips:
When pruning, cut back 6 to 12 inches below the diseased tissue and always remember to
disinfect tools after use!
Tools can be disinfected by using 70% alcohol or by soaking tools 3 to 5 minutes in bleach. Dilute
1 part of bleach in 9 parts of water.
Do not compost diseased tissues unless compost pile reaches at least 90-140 F for 2 to 3
weeks. Monitor temperature using a candy or meat thermometer.
It is also a good time to plan where to plant your annuals next year. Try to rotate or avoid
planting the same crop in the same place, as this also reduces the chances of disease.
By Erika Saalau, Plant & Insect Diagnostic Clinic
Horticultural Programs in Iowa
Upcoming statewide/multi-state horticulture conferences of possible interest to HHPN readers are listed
below. Additional information on each program is available from the listed contacts.
January 5-7, 2012
Great Plains Growers Conference
Fulkerson Conference Center, Missouri Western State University, St. Joseph, Missouri
Program Information: www.greatplainsgrowers.org
January 17-19, 2012
Iowa Turfgrass Conference and Trade Show
Downtown Marriott Hotel, Des Moines, Iowa
Program Information: Iowa Turfgrass Office (515) 232-8222 or www.iowaturfgrass.org
January 27-28, 2012
Iowa Fruit and Vegetable Growers Conference
Iowa FFA Enrichment Center (DMACC), 1055 SW Prairie Trail Parkway, Ankeny, Iowa
Program Information: www.iafruitvegetablegrowers.org
February 21-23, 2012
Shade Tree Short Course and Iowa Nursery and Landscape Association Conference and Trade Show
Scheman Building, Iowa State Center, Ames, Iowa
Program Information: Jeff Iles (515) 294-3718 or www.extension.iastate.edu/registration
March 16-17, 2012
Iowa Wine Growers Association Annual Conference
The Hotel at Kirkwood Center, Kirkwood Community College, Cedar Rapids, Iowa
Program Information: www.iowawinegrowers.org
Winter Perils for Trees and Shrubs
By Richard Jauron
Extension Horticulturalist
Iowa State University
Winter can be tough on Iowa’s trees and shrubs. Low temperatures, rapid temperature changes, winter
desiccation and the weight of ice and snow can damage vulnerable trees and shrubs.
Iowa is located in USDA Hardiness Zones 4 and 5. The average annual minimum temperature in Zone 5 is
-10 to -20 F. The average annual minimum temperature in Zone 4 is -20 to -30 F. The dividing line between Zones
4 and 5 lies roughly from Shenandoah to Ames to Dubuque.
Woody plants gradually acclimate to cold temperatures. Cold hardiness is initiated by decreasing day
length and temperature. Trees and shrubs gradually become more cold hardy during fall and early winter and
possess maximum cold hardiness in mid-winter. Cold hardiness then decreases. As a result, a temperature of -10
F in January is generally not a problem for hardy plants. However, a temperature near zero in early November or
late March may cause considerable damage to poorly adapted trees and shrubs.
A rapid drop in temperature over a short period of time also can cause severe plant damage. In Iowa,
severe damage to trees and shrubs often occurs when there is a sudden drop in temperature in fall or early spring.
The catastrophic effects of a sudden drop in temperature became painfully clear to apple growers in the spring of
1941. Prior to 1941, Iowa was one of the top apple producing states in the country. However, on Nov. 11, 1940, a
blizzard accompanied by rapidly falling temperatures (temperatures dropped 40 degrees F or more in just a few
hours) destroyed approximately two-thirds of the apple trees in the western half of Iowa.
The best way to prevent damage caused by low temperatures or rapid temperature changes is to select
trees and shrubs that are winter hardy in your area. Marginally hardy plants should be planted in protected sites,
such as courtyards or eastern exposures. Avoid summer fertilization of trees and shrubs. Summer fertilization
stimulates late season growth and delays the hardening process, making the plants more susceptible to winter
injury.
Narrow and broadleaf evergreens lose considerable amounts of moisture through their leaves or needles,
buds and stems during the winter months. The cold, dry winds and sun are mainly responsible for the water loss.
Once the ground freezes, however, plant roots are no longer able to absorb water. Plant foliage that loses a large
amount of moisture may dry and suffer desiccation injury.
Plants susceptible to desiccation injury should be planted in protected areas. A shield or screen can be
erected to deflect drying winds or shade exposed plants. A simple screen can be constructed with wooden posts
and burlap. Anti-desiccants also can be used to prevent desiccation injury. When sprayed on plant foliage, these
materials form a protective film that slows water loss. In dry years, water evergreens susceptible to desiccation
injury in fall.
Major damage to trees and shrubs also can be caused by the weight of ice or heavy, wet snow. Multistemmed evergreens, such as arborvitae, and weak-wooded deciduous trees, such as green ash and silver maple,
are most susceptible to branch breakage. High winds during an ice or snow storm can greatly increase tree and
shrub damage.
To prevent the weight of ice and snow from damaging arborvitae and other multi-stemmed evergreens,
wrap the plants with twine or soft rope in fall. When heavy, wet snow accumulates on shrubs and small trees,
home gardeners can gently shake the snow from their branches or carefully brush off the snow with a broom.
Sharply bent, ice-covered branches on small trees and shrubs can be propped up to prevent breakage. Individuals
should stay away from large, ice-covered trees. Nothing can be done to prevent damage to large, ice-covered
trees. However, an individual can be severely injured or killed if a large, ice-laden branch or tree were to suddenly
crash to the ground while he or she were underneath it.
Trees and shrubs in Iowa often have to endure a long and harsh winter. Proper plant selection, correct
placement in the landscape and good cultural practices can reduce winter injury to woody ornamentals.
Upcoming Items and Events:
Jan. 5
Jan. 6
Jan. 7
Jan. 8
Jan. 10
Jan. 11
Jan. 11
Jan. 11
Jan. 18
Jan. 18
Jan. 18
Jan. 19
Jan. 22
Jan. 25
Jan. 26
Jan. 29
Jan. 30
Commercial Manure Recertification—9:00 a.m.—Extension Office
Montgomery County Interagency—8:30 a.m.—Extension Office
4-H & FFA beef weigh in for County Fair—11:00 am.
Mont. County Youth Council Meeting—5:00 p.m.—Extension Office
Extension Council Meeting—5:30 p.m.—Extension Office
PPAT recertification—1:30 p.m.—3:30 p.m.—Stanton Community
SESS Air Rifle Practice—5:30 p.m.—American Legion—Stanton
PPAT recertification—6:30 p.m.—8:30 p.m.—Stanton Community
Crop Advantage Meeting—8:00 a.m.—Atlantic
Clover Kids—5:00 p.m.—Extension Office
4-H & Youth Committee—7:30 p.m.—Extension Office
Fairboard Meeting—7:00 p.m.—Fairgrounds Auditorium
4-H Club Officer Training—2:00 p.m.—Fairgrounds Auditorium
SESS Air Rifle Practice—5:30 p.m.—American Legion—Stanton
Ag Financial Planning meeting—6:00 p.m.—History Center
4-H new member meeting—2:00 p.m.—Fairgrounds Auditorium
Master Gardener planning meeting—7:00 p.m.—Extension Office
Montgomery County Extension Office
400 Bridge Street, Suite 2
Red Oak, IA 51566
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