||Sunny. (Green onions tolerate partial
||5.5 to 7.0
||Cool (45 to 60° F) during development.
Medium-hot (60 to 75° F) during bulbing and curing.
||Moist, but not waterlogged.
||Use sets, seeds, or transplants in the
spring for bulbs and for green or bunching onions. Seeds may
be started indoors 8 weeks before setting out; use sets in the
fall for perennial or multiplier types of onions.
||1 to 6 inches by 12 to 24 inches for
standard spacing; 4 inches by 4 inches for wide row in rows up
to 2 feet apart. Plant close, then thin using thinnings as
||Hardy biennial -- bulb onions, green or
bunching ongoing; Hardy perennials -- Egyptian onions or
perennial tree and multiplier.
||Heavy feeder. Apply 4 to 5 pounds 10-10-10
per 100 square feet before planting. Use starter solution for
transplants. Sidedress 1 to 2 weeks after bulb enlargement
begins using 3 tablespoons 33-0-0 per 10' row.
Onions are often grouped according to taste. The two main types
of onions are strong flavored (American) and mild (often called
European). Each has three distinct colors, yellow, white, and red.
In general, the American onion produces bulbs of smaller size,
denser texture, stronger flavor, and better keeping quality than
European types. Globe varieties tend to keep longer in storage.
Onion varieties also have different requirements as to
the number of hours of daylight required to make a bulb. If the
seed catalog lists the onion as long day, it sets bulbs when it
receives 15-16 hours of daylight and is used to produce onions in
Northern summers. Short day varieties set bulbs with about 12
hours of daylight and are used in the deep South for winter
For green or bunching onions, use sets, seeds, or
transplants in spring, or use Egyptian (Perennial Tree) and the
Yellow Multiplier (Potato Onion) sets in the fall.
For bulb production, plant sets in early spring. Set
one to two inches apart and one to two inches deep in the row.
Thin to four inches apart and eat the thinned plants as green
onions. Avoid sets more than an inch in diameter because they are
likely to produce seed stalks. Too early planting and exposure to
cold temperatures also causes seed stalk development. Some people
have best bulb production using seedlings or transplants rather
than sets. Egyptian Tree or Multiplier onions should be set in
late October or early November. Plant four inches apart in rows
one to feet apart. Distance between rows is determined by
available space and cultivating equipment. Plant seed in October
or November in warm areas of Arizona.
Bulbs compete poorly with weeds due to shallow root
systems. Shallow cultivation is necessary, do not hill up soil on
onions as this can encourage stem rot. Insure ample moisture
especially after bulbs begin enlarging.
Onions should be harvested when about two-thirds of the
tops have fallen over. Careful handling to avoid bruising helps
control storage rots. Onions may be pulled and left in the field
for several days to dry then cured in a well ventilated attic or
porch for one to two weeks out of direct sun. Tops may be left on
or cut off; but leave at least one inch of the top when storing.
Thorough curing will increase storage life.
||Neck or stem rot, bulb rot.
||Thrips, onion root maggots.
||Bulb rot from bruising, insufficient drying;
split or double bulb from dry soil during bulb formation; very
small bulb from too late planting or too dry soil.
HARVESTING AND STORAGE
|Days to Maturity:
||100 to 120 days for mature bulbs.
||Harvest green onions when tops are 6 inches
tall. Harvest bulbs after 2/3 or more of the tops have fallen
over. Do not wait more than 1 to 2 weeks after this occurs.
Allow for thorough drying before storage.
||10 to 15 pounds per 10-foot row.
|Amount to Raise:
||10 to 15 pounds per person.
||Cool (32° F), dry (65 to 70% relative
humidity) conditions for 6 to 7 months.
||Onions may be stored dry or pickled and
canned. They freeze well if chopped and covered with water.
For fresh storage, maintain good air circulation. One
effective storage method is to place onion in discarded
hosiery, tie a knot, and add another onion. When hose is
filled, suspend from rafters in storage area.