FAQs - Plant Pollination Problems
Nature is sometimes gentle, sometimes harsh. Mother Nature will have her
way. Mother Nature's way with pollination, does not assure success each
time....every time. Rather, problems can, and often do arise.
Most of us take the pollination process for granted. Out of necessity,
experienced gardeners learn the in's and outs of pollination . Ultimately,
they learn to identify the cause of plant pollination problems, so they can
effect a correction or cure.
Identification of the problem is vital to implementing a solution. Sometimes
the problem fixes itself over time. Sometimes, a plant pollination problem
requires your intervention and corrective actions, to turn a potential disaster
into a great crop!
The blossoms of some plants are self pollinating. There is separate and distinct
male and female flowers Good examples are tomatoes and beans. Other plants
have uniquely distinct male and female flowers. Good examples are pumpkins,
squash, and watermelon. Regardless of the type of flower, the pollen needs
to get to, and pollinate, the fruit to cause it to develop and grow.
Common Plant Pollination Problems:
Temperature Cold weather can delay the development of blossoms. Hot
weather on the other hand, can also delay blooms or cause them
to shrivel and not produce fruit.
The Cure: Await milder temperatures. As soon as the weather improves,
new blooms will appear. In cold temperatures, wind breaks, cloches,
mini greenhouses, and row covers will help
No female blossoms Males usually come to the party first. (do you
remember those days?) They come in big numbers and strut their stuff, awaiting
the arrival of the ladies. After a while, sometimes several days or more,
a few timid females begin to arrive. Usually there is no problem here, just
an anxious grower. See pictures of Male and Female
The Cure: A little more patience. A little extra phosphorous will
help promote blooms. Hold off on Nitrogen during the pollination period.
Also see Plant stress below.
Fruit Shrivels and Dies Off Pollination
did not occur, it did not occur properly, or plant stress caused the fruit
High Temperatures- As temperatures reach the high 80's, the success
rate for pollination declines. A heat wave in the nineties, will result in
poor if any, pollination. This is common with many plants, especially
with more southerly climates.
The Cure: Wait for a cool spell and nature will do it's thing. Shade
covers in hotter regions is a big help. Avid giant pumpkin growers have resorted
to building a small tent with ice or dry ice inside to lower temperatures
around the fruit! This will work on other fruits and vegetables,
Lack of Pollinators: A disease affecting honeybees has devastated
their population in many areas. There are many other insects that step in
and inadvertently do the job....sometimes. Some are harmful insects,
some are harmless. Many new growers will spray insecticides on their
plants to eliminate the many unwanted and sometimes harmful insects. The
spray kill insects and pollinators alike. The result.....no pollination.
Been there...done that.
The Cure: Buy honeybee colonies. Do not spray insecticides during
the pollination period. If you do spray during this time period, you can
always hand pollinate.
Plant Stress: In nature when a plant is under stress,
it will not produce fruit. Or, it will abort existing fruit. It is a
survival mechanism, allowing a plant to focus upon survival first. That stress
is caused by:
Water Too little or too much water.
The Cure: Keep soil consistently moist, not wet and not dry.
Soil pH imbalance pH levels are too high, or too low.
The Cure:: Get your soil tested. Alter pH levels as indicated by
Mineral and/or Nutrients Levels too high, or too low. Nitrogen is
important in early plant growth and throughout the season. Too much nitrogen
will cause lots of green leaves and growth, but can delay the flower/fruit
stage. During pollination, phosphorus will promote flowering and fruit set.
A range of micro-nutrients are also important.
The Cure: Get your soil tested. Alter levels as indicated by the
test. Cut back or halt nitrogen applications for a while. Add phosphorus.
Look for fertilizers that contain micro-nutrients, many don't.
Insect or disease problems The plant is struggling to fight off damage
from insects or disease. It will focus upon survival rather than reproduction.
It will not produce flowers and can abort existing fruit.
The Cure: Apply insecticides and/or fungicides as appropriate. Trim
and remove affected leaves and vines to promote new, healthy growth. New
growth will produce new flowers and fruit. Organic gardeners, there are