By Kate Torpie, Garden Guides Contributor
About Onions
Onion, or Allium cepa, is a cool weather vegetable that is easy to
cultivate. Its scent belies the fact that it is a member of the
lily family (and therefore toxic to many house pets). Brave people
eat onions like apples: just biting right into them. The rest of us
may enjoy onion in soups, salads, grilled over steaks or minced
into a hearty red sauce. Onions are either short-day and long-day
onions. Onion plants form a top first, and then begin to sprout a
bulb. Long-day onions will begin to form a bulb during seasons when
there are about 15 hours of daylight; short day onions will do so
when the days have only 10 hours of sunlight.
Site Preparation
If you are transplanting onions, make sure you keep your plants dry
and cool until you are ready to plant them. You can keep them for
about 2 to 3 weeks before they die. To prepare your soil, make a
raised bed (about 4 inches) that is about 20 inches wide. You are
lucky if you live in an area with rich, loamy soil. If not, buy a
good fertilizer because onions require fertile, basic soil. Use
about ¼ cup of fertilizer for every 5-foot row of
onion plants. Then cover the fertilizer with another 2 inches of
soil. An ideal site allows you to make rows in the direction of the
prevailing winds in your area. This will prevent moisture from
sitting in the soil too long, which can cause disease. Avoid
objects that may block a breeze (such as buildings or trees).
Planting
When you should plant onions depends on where you live and how many
hours of daylight you receive during the various seasons. You will
also consider the types of onions that you are planting.
Transplanted onion plants will produce the largest onions, provided
that you care them for them successfully. However, you can also buy
grow onions from sets. Sets are the simplest method and can even be
used if you have a window box or indoor herb garden. These onions
are smaller and moister, and they aren't as easy to slice. But they
are perfect if you want "green onions," as smaller baby onions are
called. If you are going to harvest green onions, place the larger
of the sets within touching distance of each other. To produce dry
(large, the kind you see at a grocery store) onions, place the
transplants about 4 to 6 inches apart. Whichever type you are
planting, set them 1 inch deep. As mentioned previously, use
starter fertilizer if your ground is not rich in nutrients. Tip:
you'll know you planted your onions too late in the season if they
sprout a white onion flower, and this will result in a smaller bulb
next year.
Care
Weather you plant transplants or seedlings from a set, the best
idea for weed control is to apply a pre-emergent herbicide. After
planning, the only good way to clean out weeds is by hand. But
avoid being too vigorous: you don't want to damage the bulb. Onions
fall prey to fungi. Blight and purple blotch are 2 such diseases.
With the first, the leaves will turn yellow. With the latter, they
develop holes that are lined in purple. Since moisture and rain
exacerbates these conditions, choose a site where wind can get to
the plants and help dry them. When you plant the onions, you will
use fertilizer. Apply more fertilizer every 2 to 3 weeks after
that. Immediately water the soil once you've put down the
fertilizer. Pay close attention to the stems of the onion; once it
feels soft and looks a bit droopy, you can stop using fertilizer.
This is also a sign that you will be able to harvest your dry
onions in about 4 weeks!
Harvesting and Storage
Pick your onions in the morning. Once the stems fall over, onions
are ready to be harvested. Just to be sure, stalks should be 6
inches tall. The taller the stalk, the stronger the flavor. Green
onions with tall stalks will most likely be way too strong to eat
raw, but they can certainly be used for cooking. If you choose to
store your onions, you must make sure they are thoroughly dry
before storing. Once you pick the bulb, leave it outdoors until the
late afternoon. Make sure you do not leave them in the bright sun,
or they will burn. Also be sure that you bring them inside before
the gloaming and dewfall. You don't want moist onions or they will
rot. It is equally important to keep them from bruising while
stored. One of the easiest (and best) ways to store onions is to
place them in a nylon stocking. Tie a plastic tie between each
onion (or put a sock between each). Hang the stocking in a cool,
dry place. This way, dry onions will last about 1 year. Green
onions will not last as long. Another tip: the sweeter the flavor
of onion, the shorter it stays good. The point brings us to
varieties,there are a lot.
Choosing a Variety
If you are going to get a set, your choices are usually limited to
color: yellow, white or red. Red are the sweetest, and yellow are
the most pungent. If you are going to transplant your onions, you
should ask at your local garden center which varieties are the
hardiest in your area. For example, White Sweet Spanish onions are
best in areas where long-day onions will thrive (such as in the
southern states). Bermuda onions are better where the days are
often short.
Special Features
Onions are high in energy and antioxidants. They increase
circulation and lower blood pressure. They contain vitamins B1 and
B6. Onions make you cry because when the cellulose is damaged upon
cutting, a chemical compound is released. The compound turns to
sulfuric acid when it comes into contact with water. Try putting
your onions in the refrigerator before cutting. The cold keeps the
chemical contact from rising, and it is less likely to reach your
moist little eyeballs.
