Container Gardening & Raised
Beds
Rachel Melvin- former Urban Horticulturalist
College of
Agriculture and
Natural Resources
Getting Started
• Container Gardening
– Advantages
– Drawbacks
– Wonderful World of
Containers
– Growing Media
– Fertilizing
• Raised Beds
–
–
–
–
Advantages
Drawback
Building Material
Framed & Unframed
Container Gardening
• Can utilize small space
• More control over soil
media, water, light,
nutrients, location, etc.
• Raised height may aid those
with back or knee problems
• Fewer weeds
• No need to till
• Vertical growth saves space
Possible Drawbacks
• You have more control 
• Need to pay more attention
to type of media plants are in
• Water more frequently
• More caution with fertilizer
Choosing a Container
Type
Pros
Cons
Plastic
Light – easy to
move
Can blow over
Use ones
specifically for
outdoors
Need to insure
good drainage
Will break down
quickly
otherwise
Avoid dark colors
–heat rapidly
Choosing a Container
Clay/Ceramic
Won’t blow
over easily
Heavy
Generally more May dry out
attractive
quickly
Wood
Can rot- avoid
ones treated
with creosote
Self Watering Containers
• Have a reservoir below the
media that holds up to a
weeks worth of water.
• Allows plant roots to grow
deeper and heavier
• Can buy commercial or make
your own
The Earth Box
Sizing Containers
• Recommended Media Depth:
– 4-6”: salad greens, mustards,
garlic, radish, basil, cilantro,
thyme, mint and majoram
– 8-12” beans, beets, chard,
carrots, peppers, eggplant,
tomato, squash, rosemary,
parsley, lavender and fennel
Sizing Containers
• Recommendations by Volume:
– 1-3 gallon pot: herbs, onions,
pepper, dwarf tomato,
cucumber or basil
– 4-5 gallon pot: full sized tomato,
cucumber, eggplant, beans,
peas, cabbage and broccoli.
– Smaller pots dry out more
quickly than large ones –check
daily!
Whiskey Barrel 1 to 2 plant
capacity
8 cu. Ft. of growing media
Growing Media
• Growing Media
• 100% Soilless mix(light and
few nutrients)
• 25% Soilless+ 25% Garden soil
+50% Compost
• 50% Soilless Mix + 50%
Compost (my favorite)
• Use your own compost
General Care
• Veggies require a pH
between 5.5 and 7
• When combining ornamental
and vegetable/herb, group
plants by similar needs: ie,
most herbs need sandier soil
and full sun-porous
containers are perfect.
General Care
• Pre-water the media before
planting
• Make sure drainage holes are
adequate. Don’t let plans sit
in a full saucer.
• Over watering can cause as
much damage as under
watering! Check moisture
with your finger.
Fertilizing
• ‘How Much’ and ‘how
often’ depend on type of
fertilizer, plant and
container.
• Nutrients leach easily from
containers, so crops (even
quick ones like lettuce or
brocolli raab) usually need
to be fertilized several
times.
Fertilizing
• Long season crops like
tomato, cucumber, eggplant
and pepper might need light
fertilization every 2 weeks.
• Soluble fertilizers are quick
and recommended for
containers
• Slow release works well, can
be more expensive, but lasts
2-4 months
Organic Fertilizers
• Emphasizes soil improvement
through addition of organic matter
• Liquid Sea Kelp and fish fertilizer can
be made water soluble
• Blood meal, composted chicken
manure, cottonseed and alfalfa meal
and worm castings are dry fertilizers
that can be incorporated at planting
and reapplied as needed.
University of MD Salad Table
Salad Table features
• Cost about $35 each in materials; takes 2-3
hours to build
• 58” long X 33” wide X 3.5” deep
• Growing area surface- 11.1 sq. ft.
• Growing area volume- 2.8 cu. ft.
• Frames placed on saw horses or legs at
desired height
“Salad Box”- 15 in. X 21 in.
Raised Beds
• Warm up quickly in spring.
• Drain well; less compaction
and erosion.
• Increase available rooting
area.
• Can produce greater
yields per square foot
Drawbacks
• Up-front labor and expense.
• Dry out quickly if weather is
hot and dry.
Constructing a Raised Bed
Size
row of bush beans
plants
3 tomato
8 ft
• A bed 3-4 feet wide is ideal for most
vegetable crops,
2 cuke plants
4 ft
– allowing the gardener to reach the entire
bed from the side
• Tomatoes are well suited to a bed 24” to
36” wide, with one row of plants down the
middle.
• Beans and peas are easier to pick in a
single or double row down a bed rather
than in the block-style planting. Here a bed
24 “ wide would be ideal.
• Length can be what ever works for the
space.
Constructing a Raised Bed
Depth/Height
• Here a four-inch height would be adequate.
– Variations in heights (4”, 6”, 8” and 10”)
among different beds
• In situations where the soil below is not
suitable for crop growth, eight to twelve inches
of soil is considered minimal.
• To accommodate gardeners with special needs,
bed height may be raised to minimize bending
or to allow gardening work from a wheelchair.
• For ease of irrigation, beds should be
reasonably level, both across and lengthwise
Raised Beds-Building Material
• A simple way to construct a
raised bed garden is to use
construction lumber (2x4,
2x6, 4x4, 4x8). Untreated
lumber will last for several
years( up to 10 years), except
in high salt areas or wet sites.
• ACQ pressure-treated lumber
contains copper, but no
arsenic. We don’t have
sufficient research
information to assess
potential health risks.
• Brick or other building
materials may also be
suitable.
Simply cut two pieces the width of the bed
(typically four feet) and two others to the desired
bed length. Using three and one-half to four inch
decking screws, screw the corners together to
make a four-sided box. Place the box-like frame
on the soil and fill.
Unframed Raised Beds
• Raised beds may also be made
without sides.
• Organic matter is mixed in at the
same time the garden is tilled.
• Walkways are dug down with the
soil thrown up on the bed.
• Beds are four feet wide at the
base and three feet wide at the
top.
• The entire bed is covered with
organic mulch like dry grass
clippings to prevent soil erosion
and reduce compaction from rain
and sprinkler irrigation.
Resources
• Grow It! Eat It!
http://www.extension.umd.edu/growit
– We have all types of practical food gardening tips and
information. Check out our popular blog!
• Home and Garden Information Center
http://www.extension.umd.edu/hgic
– Here you will find factsheets, photos, and videos. You
can also subscribe to the free monthly e-newsletter.
– We answer gardening questions 24/7…just click
“Ask Maryland’s Garden Experts”
• Maryland Master Gardener Program
http://www.extension.umd.edu/mg
– Consider becoming a trained MG volunteer!
This program was brought to you by the
Maryland Master Gardener Program
Washington County
University of Maryland Extension