Planting Guide
Onions
Soil Preparation And Plant Selection
Onions prefer loose, well-drained soil, so take the time to
amend your soil well. One or two cubic feet of Soil Pep, manure,
Sunshine Peat Moss, or other well decomposed organic matter
plus one half pound of Bookcliff Gardens Choice Vegetable Fertilizer,
per twelve square feet tilled into the soil to a depth of 6"
to 8" will give your onions a good start.
Dry onion sets are an old, reliable method of planting onions
although the varieties available are more limited. Obtain your
sets early when they are firm and dormant. Sets are generally
available in three colors: red, white and yellow. Use bulbs
that are larger than a dime for green onions because these may
bolt and not produce good dry bulbs. Use the bulbs smaller than
a dime for normal onion production. Green plants have become
more available recently and offer reliable production with better
variety selection.
.
Planting
Onion sets are usually planted in March or April. If planted
when the weather is too cool, there is a tendency to get seed
stalks instead of onion bulbs. Space your rows 1 to 2 feet apart.
Place your bulb sets 1 to 1 1/2 inches deep and 3 to 4 inches
apart. Green onion plants should be planted as they're growing
in the flat and spaced 3 to 4 inches apart. Many people crowd
in their sets, spacing them 1 or 2 inches apart, and then thinning
them as they grow, using the thinned plants for green onions.
Maintenance
Water as necessary to keep the soil from drying out. Do not
keep the soil so wet that it causes the bulbs to rot. Break
off any flower stems that appear. Mulching can be useful to
keep the need for water down and to prevent weeds from sprouting.
Once the bulbs have swollen, pull the mulch back to expose the
tops of the onions to the sun.
Harvesting
You can start pulling green onions in 3 to 4 weeks. It takes
about 20 weeks to form a mature onion bulb. The bulbs are mature
when 80% of their foliage turns brown and falls over. Onions
that are not for immediate use need to be dried. You do this
by lifting the onion up just enough to break their roots off.
Leave them where they are in the ground. When the tops have
totally dried, lift them and put them in a burlap or mesh bag.
Leave your onions in the garden until you can lift the bag and
hear a rustling of the dry skins. Onions will tolerate frosty
nights but cannot withstand a freeze. If freezing temperatures
are in the forecast, move your onions indoors until the threat
of frost has past. The onions are now cured and can be moved
to a dry, dark storage area. Try to keep the temperature between
35 and 40 degrees.
Back to the top.
Bookcliff Gardens
(970) 242-7766
755 26 Road (North 1st at I-70) • Grand Junction, Colorado 81506
Ask the Expert
©2008, Bookcliff Gardens
