i
ask the experts
Q
I’m a novice grower, but my cucumber plants are producing
a ton of flowers—clusters of two or three big yellow
blossoms with tight internodal spacing. It seems like
a lot to me. Should I pinch some of them off?
All of them? Should I be
concerned about future
pollination if I do?
Thanks for any advice
you can offer,
Matt R.
A
Hi Matt,
Cucumber plants that are healthy and growing
vigorously under good conditions can develop
an excessive number of flowers—far more than
the plant can successfully carry through to fruit
maturity—particularly, early in the plant’s life.
Often, if left to their own devices, the plant will
naturally abort a number of small fruitlets,
leaving only those that can be supported.
However, flowering/fruitlet pruning depends very
much on the type of cucumber you are growing.
The small Lebanese or snacker cucumber vari-
eties produce smaller fruit, so growers typically
allow two to three fruits to set at each node as
the plant can easily support these. If growing the
large, seedless, continental greenhouse types—
sometimes called European, Japanese, or English
cucumbers, and are the most commonly grown
hydroponically—then all the flowers should be
female as the plants are gynoecious (that is, they
only produce female flowers as pollination is not
required to set and produce fruit). In this case, the
small fruitlets, which have flowers attached to the
end, would be thinned to one per node. If you are
growing the seeded American slicer or other sim-
ilar large-fruited and seeded cucumbers, then the
plants need both male and female flowers for pol-
lination to occur. Often, early in the life of a seeded
cucumber type, it will first produce a large number
of male flowers. These are flowers that don’t have
the small cucumber fruitlet at the base as female
flowers do. In this case, excessive male flowers
can be removed until the first female flowers are
seen. Then pollination can occur. For large-fruited,
seeded cucumbers, ideally only one fruit per
node should be allowed to develop. You can wait
until after pollination has occurred and the small
fruitlets have started to grow before selecting the
largest fruitlet to grow in each node.
PARTHENOCARPIC
A quick side note: Often, not all the flowers will
pollinate if there are multiple flowers in each
node. (Also, some of these flowers will be male and
naturally fall anyway.) If growing in a greenhouse
or indoors, there also may not be any insects to carry
out the pollination process. In this case you will
need to transfer pollen from the male to the female
flowers. Since this is a time-consuming process,
most hydroponic growers prefer the seedless/
gynoecious cucumber varieties that set seedless
fruit without the need for pollination.
Overbearing can be a problem in many cucumber
varieties when under good growing conditions.
This can lead to the plant become exhausted
and aborting flowers and fruitlets later on. So, to
improve fruit size and keep the plant cropping
for longer, the number of fruit is controlled with
fruitlet pruning where required. Remember that
initially, the first few fruitlets on the plant may
wither and fall. This is a normal process for many
varieties. The plant will set and carry fruitlets
further up the vine once this has occurred and it’s
no cause for concern.
Good luck with the cucumber plants!
Kind Regards,
Lynette Morgan
Dr. Lynette Morgan holds a
B. Hort. Tech. degree and a PhD in
hydroponic greenhouse production
from Massey University, New Zealand.
Lynette is a partner with Suntec
International Hydroponic Consultants
and has authored several hydroponic technical
books. Visit suntec.co.nz for more information.
Parthenocarpic cucumbers are hybrid plants that have been bred with emphasis on the incompletely dominant gene Pc,
which allows these varieties to produce fruit asexually. They produce few or no seeds. Any seeds that do ripen will not be
fertile. Parthenocarpic cucumber seeds must be sourced annually. Parthenocarpic cucumbers are nearly all gynoecious,
meaning that they only produce female flowers. Not all gynoecious cucumbers are parthenocarpic, however.
– hunker.com
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