trends & technology
Oca tubers (also called yams) are
planted into a hydroponic system
once they have sprouted new shoots.
“WHILE these crops can
all be grown to full or even
super size in hydroponics, they
are more often grown rapidly and
harvested as baby gourmet veg.”
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grow cycle
Sweet potato, which requires a longer growing season
than potatoes, can be sprouted by placing them on a tray
with a layer of clean, damp sand or perlite under warm
growing conditions. Eventually, the buds on the tubers will
form many shoots, each with a few roots at the base. These
shoots can be peeled from the tuber and planted out to
produce a sweet potato plant.
Potato and sweet potato can be grown in large pots, beds,
containers, or bato buckets. They can also be planted into
potato bags. These flexible bags have a flap in the front wall
that can be opened once the plant has reached a suitable
stage of development, and young, small potatoes extracted
from the root zone without damaging the plant. This allows
for a successive harvest of tubers as the plant continues to
develop. The removal of small tubers during the growth phase
induces the plant to continue forming more potatoes, with a
final harvest occurring once the crop tops start to naturally die
back. Another option is to grow tubers using aeroponics so the
root system can be viewed inside the misting chamber and
crops removed when of a sufficient size. Tubers will also grow
and produce well in nutrient flow technique systems,
provided the dimensions of the channel are suffi-
ciently large enough to accommodate the sizable
root system and tubers that will develop.
Root Crops
Carrot, parsnip, radish, turnip, and beet all
develop a thickened tap root, which is the main
edible portion of the plant. While these crops
can all be grown to full or even super size in
hydroponics, they are more often grown rapidly
and harvested as baby gourmet veg. For this
purpose, selection of the correct cultivar is vital.
Seed suppliers have impressive ranges of vari-
eties to choose from. For example, carrot cultivar
Adelaide F1 is a true baby variety that forms a blunt
root and matures early and is well-suited to hydro-
ponics. Another option with root crops is to grow
unusually colored types, such as purple, white, or
yellow carrots; black or white radish; rainbow or
pink and white striped beet; and golden, cream, or
purple turnips. These all add great variety to baby
root vegetable mixes and dishes.
Growing root crops for harvest at an imma-
ture stage doesn’t require an overly deep bed or
container system. Seeds are sown directly into
the surface (small, difficult-to-handle seeds like
carrot can be purchased in pelleted form, which
is ideal for hand sowing small areas) and then
thinned to the correct spacing after germination
has occurred. As an alternative, seed tapes can
be used to obtain the correct spacing without the
need for thinning. These are paper tapes with
seeds imbedded along the length. The paper
breaks down as the seedlings develop, leaving
plants at the ideal spacing. Quick-to-germinate
types such as radish only take a few days to
emerge, whereas carrots and parsnips are consid-
erably slower and can take up to three weeks. If
growing a range of different root crops, these are
best kept in separate containers or rows due to
different rates of development.