Bulb Crops
Onions and garlic are the most commonly grown vegeta-
ble bulb crops. Even with these plants, diversity exists with
color, form, and flavor. In an indoor garden with limited space,
growing small cippola-style or cocktail onions such as Barletta
or milder-flavored shallots is often a good option.
With onions, bulbing is induced by the number of hours of
light each day. Long-day onions require 14-16 hours of light,
intermediate onion cultivars need 13-15 hours, and short-
day cultivars require 12-14 hours. So, selection of the correct
cultivar for the number of hours the lights are run per day
in an indoor garden is critical for bulb formation. Most seed
suppliers provide the information for each cultivar. Onion
seeds are slow to germinate; however, these can be planted
out as sets, which are young, well-developed plantlets that
significantly reduce production time.
Unusual Subterranean Crops
Within the tuber, bulb, and root crops, there
are some lesser-known plants that provide
an interesting alternative for hydroponic
production. These include ulluco, a small,
colorful tuber originating from South
America, and oca, one of the many species
of yam. Both ulluco and oca are relatively
small plants well-suited to hydroponics.
They are grown in a similar way to potatoes,
with the tubers pre-sprouted under warm
conditions, then planted out into a growing
bed where vegetative growth occurs rapidly.
Both need a long growing season to form
tubers. Ulluco has the advantage that its
foliage can also be steamed and eaten as a
fresh vegetable similar to spinach.
Many types of bulbing onions are suited to growing
in hydroponic gardens.
“SELECTION of the correct
cultivar for the number of hours the
lights are run per day in an indoor
garden is critical for bulb formation.”
Small button or cocktail onions make a
great addition to the range of edibles
grown hydroponically.
grow cycle
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