Monday, April 22, 2013

Hand Pollinating Your Garden

Have you ever wondered why vanilla beans cost so much? They must be pollinated by hand! This is a crop that has unique circumstances. The flowers of the vanilla orchid only stay open for one day. If left up to nature, the vanilla bean would be very rare. Considering that vanilla is in high demand as one of the most common flavorings, hand pollination is required!

Is there ever a time when you would need to (or want to) hand pollinate your plants yourself? Yes! As the vanilla orchid shows us, sometimes nature needs a helping hand. The primary reason you would want to do this, in your garden, is if you don't see sufficient bees or other pollinating insects doing the job for you. You would know you don't have enough pollinating insects when your plants are not yielding a harvest. 

Sometimes row covers are used in home gardens specifically to keep out bad bugs, like the squash vine borer. However, when you keep out the bad bugs, you also keep out the good bugs. Fruits and vegetables grown in a greenhouse are in the same situation. No bugs means nature needs a helping hand to get a harvest.

Row covers would also be needed if you want to plant two varieties of the same type of plant, and save the seeds from both of them. A common example of this would be two different types of squash or pumpkins. In this situation, row covers and hand pollination would be required to keep the seed of both varieties pure.

Different plants require different steps to pollinate them. Some plants popular in the home garden are self pollinating and don't require any assistance:
  • peanuts
  • spinach
  • lettuce
  • peas
  • snap peas
  • lima beans
  • green beans
These plants self-fertilize before the flowers even open and can be grown successfully in a greenhouse or under row covers without human help.

Vegetables like tomatoes and peppers also self-fertilize but need help to do so. This can be accomplished by gently shaking the plant every few days. Shaking the plant will mimic the breezes the plants get out in the open garden. Vibrations from the breezes are how the flowers from these plants pollinate and produce a harvest. .

Plants with separate male and female flowers on the same plant, need human intervention.  Common home garden plants in this category include:
  • squash
  • pumpkins
  • cucumbers
  • cantaloupes
  • watermelons
  • gourds
  • kiwi (Kiwis have male flowers on male plants and female flowers on female plants. You will need both types to get a harvest)
Fruits that require two varieties to get a good crop (like apples and pears) also fall into this category as well.

The good news here is that hand pollination is very easy to accomplish. All you need is a small paintbrush or cotton Q-tip swab. With squash, pumpkins and cucumbers, start with the male flower. (The male flower does not have a small fruit attached to it.) For fruit trees, start with any flower on one tree. 

Take the paintbrush or cotton swab and gently brush the inside of the flower. You want to gather pollen on the tip of the brush. Do this to a few male flowers before moving to the female flowers. For fruit trees, visit a few flowers on the same tree. Check the tip of the brush to see if there is pollen on it.  You will be able to easily see the pollen. If you can't, brush a few more male flowers until you can see the yellow pollen.  In this picture I am gathering pollen from one of my apple trees.


Once you have enough pollen to see it on the end of the brush, move to a female flower and gently brush it. You should have enough pollen on your brush to pollinate a few female flowers. For fruit trees, move to the second tree and brush a few of the flowers. 


For squash type vegetables, visit two or three male flowers for every female flower. You can also cut the male flower off the plant (at the stem) and bring it to the female flower. Using the male flower as the brush, gently swab the female flower. 

Technically, the pollen needs to be deposited on the stigma of the flower. However, the parts of a flower can get really complicated because self-fertile plants have flowers that are different from plants that have both male and female flowers. So, the short lesson here is to make sure you brush all over the interior of the flower.

This process isn't time consuming. It shouldn't take more than 10 minutes to pollinate four or five plants. One note of caution, if you are planning to hand pollinate more than one type of plant, clean the brush between plant varieties. Pollinate all the squash, clean off the brush, (or get a new Q-tip) then start on the pumpkins. Repeat the process in four or five days.

If this process sounds like too much work for you, you can always become your own bee keeper! That has added benefits of harvesting your own honey supply!

Really, your best bet is to set up your garden to encourage all kinds of bugs to visit. Yes, you will get some of the bad bugs, but you will get many more good bugs to keep your garden in balance.  Lots of good bugs visiting your vegetable flowers, is the best guarantee for a good harvest!

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