beginner’s corner
Forcing Lilies Hydroponically
“‘Forcing’” refers to
the use of environmental
control or other techniques
to induce plants to flower
on schedule, often to
target specific markets like
Christmas or Easter.”
Commercially, the forcing of lilies
for cut flower production is common
practice amongst greenhouse growers.
The same principals can be applied
on a smaller scale in an indoor
garden. “Forcing” refers to the use
of environmental control or other
techniques to induce plants to flower
on schedule, often to target specific
markets like Christmas or Easter. The
technique of forcing is now less based
on traditional methods of growing
plants in soil or potting them into large
containers of substrate, and more on
the use of bulb crates similar to those
used commercially to force tulips and
other similar cut flower bulb crops.
Lily forcing crates are sturdy, black,
rectangular plastic crates with an
open structure into which bulbs are
densely packed in a small volume of
substrate. Crates used in greenhouse
forcing are typically 24x15x10 inches
and hold 10-18 bulbs, depending on
cultivar and size. The crates provide
a mobile system in which the bulbs
can be moved into and out of chillers
or cool rooms as part of the treatment
process and allow more rapid produc-
tion of blooms. On a smaller scale, use
of smaller-sized bulb crates allow lily
bulbs to be grown separately from the
main hydroponic system and shifted
around an indoor garden as space
permits. Using pre-chilled lily bulbs,
placed into bulb crates, and grown into
a warm, well-lit growing area provides
a system of rapid production of flowers
and, if timed well, can provide blooms
ready in time for Easter or Christmas.
Hydroponic Systems
for Lily Production
Apart from forcing systems like bulb
crates, lilies grow well using several
different hydroponic techniques.
Research has shown that lily bulbs
can be supported in large stone wool
cubes using NFT or ebb and flow
methods to deliver the nutrient solution
intermittently. For bulbs grown in pots,
containers, beds, troughs, or other
substrate systems, selection of the right
type of hydroponic medium is essential
for hydroponic lilies. Coarser grades of
composted bark, coconut fiber, sawdust,
perlite, and various combinations of
these usually gives good results. On a
small scale, standard grow and bloom
nutrient products can be applied during
the growth phase. Lilies are not initially
a high nutrient demanding crop as the
bulb remains a reservoir of nutrients
during early growth; however, once
stem growth and bud development has
occurred, calcium and potassium need
to be boosted to ensure strong flower
formation. During the bud development
stage, a suitable lily hydroponic nutri-
ent formation contains the following
levels of elements:
ELEMENT
Nitrogen
Phosphorus
Potassium
Magnesium
Calcium
Sulfur
Iron
Manganese
Zinc
Boron
Copper
Molybdenum
ppm
227
100
340
80
197
108
5
2
0.25
0.70
0.07
0.05
Left: Lilies, depending on cultivar, can be tall plants that benefit from staking. Right: Lilies are available in wide range of colors and varieties.
102
grow cycle