2215 Planting Annuals
By: Alisa Amy Kowalski
What is an Annual?
• Plant that completes its life cycle in one
season
• Growing from seed in the spring, flowering,
and then producing fruit that contains seeds
before dying in the fall
• Put on a splendid show from May to
September
Culture of Annuals
• Whole purpose to produce seed
• Once it does so, it generally stops flowering
• Flowering period can be extended by
removing faded blooms as soon as they
finish flowering to promote flowering all
summer long
Uses of Annuals
•
•
•
•
•
•
•
•
Alone in a garden
Window boxes
Planting tubs
Temporary Hedges and Screens
Vines
Cut Flowers
Brighten up areas
Best when planted in large expanses or beds
Benefits to Annual Flower Beds
•
•
•
•
Continuous source of cut flowers
Flower borders to act as transition zone
Inexpensive way to landscape
Fillers
Planting Methods
• Best if planted in groups of no less than
three to five plants
• Grown in large clumps or varicolored drifts
of the same plant or a variety of plants of
the same color
• Rarely is a single plant effective, as it tends
to become lost in the overall landscape
Soil and Location
• Most annuals do best in an open, welldrained, loamy soil, in a sunny location
Fertilizing I
• Apply 2 pounds of a complete fertilizer, such as 510-5 per 100 square feet, when the soil is worked
in the spring
• If plants are growing poorly in midsummer they
may require additional fertilizer
• The three numbers on a fertilizer bag refer to the
percentage by weight of nitrogen, phosphorus, and
potassium present
• Phosphorus is in the form of P2O5
• Potassium is in the form of K2O
Fertilizer II
• Soil test in the fall or spring is
recommended before application of
fertilizer
• Avoid fertilizers with high nitrogen content
• This may cause excessive vegetative growth
and few or no flowers
Watering
• Should be watered thoroughly at least once a week
during the summer if there is not sufficient rain
(less than ½ inch per week)
• Enough water should be added to thoroughly
moisten the soil at least 6 inches
• Young plants should be waters after transplanting
• High amounts of phosphorus will promote root
development in these plants
Cultivation and Mulching
• Weeds can be controlled by either
• Mulching may be an easier, more economical way
of suppressing weeks than mulching according to
some gardeners
• Materials used for mulch
–
–
–
–
–
–
Corncobs
Peat moss
Buckwheat hulls
Sawdust
Woodchips
Newspapers
Planting Seeds and Transplanting
• Most seeds can be sown outdoors from April 1 to
the middle of May in central lower Michigan
• Follow directions on the seed packet
• To avoid transplant shock set the plants outside
when there is not a lot if sun
• Plants should be set in the ground ½ to 1 inch
deeper than they were initially planted
• A started solution should be used to provide young
plants with early nourishment
Buying Annuals
• Select healthy, bushy plants
• Plants that can be purchased flowering
– Geraniums, petunias, sweet alyssum, and dwarf
French marigolds
• Plants that should not be in bloom when
purchased
– Snapdragons, salvia, scabiosa, and zinnias
Starting Annual Seeds Indoors
• If seeds are started indoors they will bloom
6 weeks earlier as opposed to sowing seeds
outdoors in late spring
Soil Mixture or Growing Medium
• Use a commercially prepared mix
containing perlite, vermiculite, and peat
moss for best results
• If you want to mix your own starter soil, use
a soil mixture of one part good garden soil
and one part peat moss
Sowing Seeds – Large Seeds
• Marigolds and Zinnias
• Make holes in soil 1 inch apart with pencil
• Two seeds should be placed in each hole,
and depth should be two or three times the
greatest dimension of the seed
• After the seeds are in place, firm the soil
gently
Sowing Seeds – Fine Seeds
• Flowering tobacco
• Broadcast over the soil surface, allowing
about ¼ inch space between seeds
• Do not firm the soil
• Very thin layer of soil mixture should be
sifted over the seeds
Pelleting
• Some fine seeds are pelleted
• Covered with a material to make them
bigger
• Makes fine seeds easier to sow
• Reduces the number of seeds used
Flowering Planting Seeds…
•
•
•
•
Label with names so they are identifiable
Include variety name – needed for exhibiting
Water carefully – avoid washing seeds out
To avoid problems use capillary action watering
– Place in pan of water to allow soil to pull up water
• Cover with plastic film – retain moisture
• Film should be folded under the seed box
• Airtight seal is not necessary, but the film should
completely enclose the box
Germination and Culture
• Most seeds germinate best at 750F
• Light is not essential for germination
• Seedlings should appear within 3-14 days
–
–
–
–
Check boxes daily for signs of germination
When germination has occurred, remove plastic
Expose to full sunlight & temperature 65-700F
If the cover is left on too long, spindly growth will
result and seedlings will be susceptible to damping-off
disease
Damping-off Disease
• Under poor light and stagnant air, may
occur even in pasteurized soil
• Stems weakened at the soil line by the
invasion of a fungus – seedlings fall over
• Can spread through seed box in 2-3 days
• Chemicals available to control the disease
• Prevention is the most important and
effective method of control
Fertilization
• Applied after germination will produce sturdy
plants
• Any soluble complete fertilizer at half the strength
recommended on the container will produce
healthy plants
• Two weeks later, and every two weeks thereafter,
the same fertilizer should be applies at the rate
recommended on the container
Watering
• Careful attention is the key if starting indoors
• Never allow to dry to the point of wilting
• Severely slows growth of plants for several days
following apparent recovery
• When the soil feels dry to the touch – water
• Do not water again until needed
• Over-watering can be as fatal as not water at all!
– It drives the air out of the soil
Thinning & Transplanting - Large
• After “true” leaves show above the seedling
leaves, the plants are ready for spacing
• Annuals were sown two seeds per hole
• The extra plants should be cut off at the soil
line with a pair of shears to allow a 1” space
• Prevents injury to the roots of seedlings
Thinning & Transplanting - Fine
• Fine-seeded plants that were sown
broadcast should be carefully lifter and
pried out and transplanted into additional
boxes, by placing a knife or stiff stake under
the roots and then lifting the seedling out
while gently pulling on the top
• Place seedlings 1 inch apart from each other
• Gently firm the soil and water
Conditioning
• On balmy spring days when the wind is
calm, young plants may be “hardened” for
their final life outdoors by placing them in
full sunlight for several hours
• They dry rapidly under these conditions, so
watch carefully and water them when
necessary
Final Transplanting
• Ready for final placement when the danger
of frost has past
– Around May 20 in Central Lower Michigan
• A rule of thumb for anywhere in Michigan
– It is safe to plant or set out annual flowers when
the first sugar maple leaves are fully expanded
– Try to set out plants in the evening or on a
cloudy day if at all possible
Common & Scientific Names
• Since many plants have more than one common
name, the common and scientific names of the
plant are given here to avoid confusion
• Some plants have over 200 common names
• Main advantage – one plant – one name
• Single name is used all over the world
• Composed of two parts and usually latin
• First word is the genus, the second word is the
species