For:
By: Daniel E. Mullins
Extension Horticulture
Agent
Pollination – the
Garden’s Unseen Miracle
Pollination is the transfer of pollen from the anther, or male part of
the flower to the female part or stigma.
Following pollination, fertilization must then occur through the union of
male and female cells. Though this
process goes mostly unseen, it is necessary for fruit development in most
cases.
Each spring gardeners submit very specific questions related to this
subject. Following are some
examples:
Q.
If I plant two
different varieties of the same vegetable near each other in the garden will the
resulting fruit be a mixture of these two varieties?
A.
No, the resulting
vegetable should have the characteristics of the original variety planted during
the first generation from seed. The
result of cross pollination would only begin showing up if you saved seed and
produced plants from them in the future.
Since most currently used vegetable varieties are hybrids, saving seed is
not recommended.
As always, there are a few exceptions. Sweet corn, when fertilized with pollen
from a different variety, can result in color and flavor differences. The result of cross pollinated peppers
also shows up in the first generation.
For example, if you plant sweet and hot peppers too near each other you
might harvest sweet peppers that are also hot.
Q.
I would like to
plant both white and yellow sweet corn.
How can I prevent the two varieties from “mixing”?
A.
This can be
accomplished by separating the two planting dates or by distance between
plantings. Sweet corn is wind
pollinated, so if planted at the same time, the two varieties should be at least
300 feet apart. Planting at least
two weeks apart should also be sufficient to avoid cross
pollination.
Q.
I have problems
growing cucumber, squash and watermelon.
They won’t set fruit even though the plants appear healthy. What am I doing
wrong?
A.
This is probably due
to a lack of pollination. All of
the cucurbit crops have separate male and female flowers on the same plant, but
in different locations. They are
insect pollinated, and honey bees are by far the most efficient movers of
pollen. In many areas there appears
to be a lack of sufficient bees to pollinate these plants.
It takes approximately eight flower visits by bees to result in a well
developed fruit. New flowers open
each morning and bees are most active from shortly after sunrise until
mid-morning.
In the absence of sufficient bees, you can try the hand pollinating of a
few plants. This can be done by
transferring pollen from newly opened flowers using a small brush. Deposit it on the stigma, which is on a
raised area in the middle of the female cucurbit flower.
Q.
How
long does it take for vegetables to produce fruit after
pollination?
A.
This varies with the kind of vegetable. Summer squash only requires five to
seven days, while butternut and other winter squashes require up to two
months. Tomatoes and peppers need
about six weeks.
Pollination is a
fascinating subject and there is plenty of information available for the
gardener. The