Most people look at flowers and admire them for their colour, shape, size and or smell, unless the plants were planted to produce seeds or fruit (and then how the flowers look is secondary to what they produce).
Flowers are either complete or incomplete. A completed flower contains both the pistil, female part, and stamens, male part. Incomplete flowers contain either a pistil or stamens.
Pollination takes place when the pollen from the stamen enters the pistil. In a complete flower, this can be as simple as the plant swaying in the wind. With incomplete flowers and some complete ones, the pollen must be moved from one flower to the next.
Pollen can be transferred between flowers by wind, insect or man.
Most corn plants are pollinated by the wind. For this reason, it is suggested that corn be planted in groups or a number of short rows as opposed to one long row. There is more chance of the plants being pollinated if the wind can move pollen in any direction. It is important not to plant two different varieties of corn, decorative and edible, too close together as the plants will cross pollinate, resulting in mixed cobs.
Tomato flowers are complete. When left in the elements, they pollinate quickly but often need a nudge if they are under cover to dislodge the pollen into the pistil. Gently shaking the plant often is enough to cause pollination. According to the Stokes seed catalogue, the optimum time for pollination is between 10 a.m. and 2 p.m. People have also had good results pollinating tomatoes by running a feather over all the flowers.
There is a product on the market to get tomatoes to set. Spraying the liquid directly on the flower puts the pollen in contact with the stamen.
Cucumbers, pumpkin, melons and squash flowers are incomplete. The male flowers usually appears first, followed by the females a week or so later. It is easy to differentiate between the two as the female flower is attached to a very small fruit.
If there are enough insects in the vicinity, pollination will occur when the insect moves from one flower to another. If insects are scarce, it is up to the gardener to pollinate the flowers. It can be accomplished by rubbing a Q-tip on the stamen of the male flower, then the pistil of the female flowers. Picking the male flower, removing the petals and rubbing the stamen on the pistil of the female flower will also result in pollination. The miniature fruit will whither, turn yellow and drop to the ground if the flower has not been pollinated.
Apples, cherries and grapes have complete flowers but most varieties are not self pollinating. This is why it is suggested that there is a need to purchase two plants or a pollinator. Urban gardeners might want to scout out their neighbourhood to see if there are already pollinators established in other yards. The plants do not have to be the same variety to work. A crab apple will pollinate an apple tree. To be successful, the flowers have to be open at the same time.
Pollination is not a concern in the typical flower garden unless seed is being saved. Newer hybridized varieties of annuals, the ones that do not have to be deadheaded, do not set seed. Spent flowers are only removed to improve the aesthetics of the garden. Removing spent flowers before seed can form will help some of the older varieties to bloom for a longer period of time. With perennials, it can produce a second flush of flowers. Flowers are an attractive and useful part of the garden. Managing the flowers has a huge impact on the output of the garden.
Linda Tomlinson is a horticulturalist who lives near Rocky Mountain House. She can be reached at firstname.lastname@example.org.