2014: Year of the cucumber

Each year the National Garden Bureau selects a perennial, annual and edible to become the chosen plants of the year. This year they have chosen cucumber as the edible of the year. Cucumbers are a gardener’s favorite for eating fresh or for making pickles that can be enjoyed for months after the garden is put to bed for the winter. These easy-to-grow plants don’t need any special growing conditions except a sunny location and some room to grow.

Historical records indicate that this popular fruit originated in Asia and has been cultivated for more than 3,000 years. Cucumis sativus is a member of the Cucurbitacea family and is related to other common garden fruits like squash, watermelon and pumpkins. Cucumbers and these other cucurbits are all creep vines that will grow along the ground or up onto a support by gripping it with tendrils that appear along the stems. There are also bush-type plants that take up about half as much space and can still be as productive as the full-sized plants. You can also grow them on a trellis or cattle panel to save even more space and make harvesting easier. Large containers can also be used to grow cucumbers on a deck or sunny patio.

Plants are usually monoecious, meaning that they produce both male and female flowers on the same plant. Pollen needs to be transferred from the male flowers to the female flowers, usually by bees, in order for fruit to be produced. You can tell the difference in the flowers by looking for the ovary, a tiny immature fruit, which will be located right at the base of the female flowers. The male flowers will generally be on a longer stem and have visible pollen on the anthers inside the flower. There are times when cucumber plants may produce almost all male flowers, especially early in the season or during unfavorable growing conditions. When this happens, gardeners may notice that there are lots of flowers but very few fruit to harvest. This problem will usually get resolved with improved growing conditions and fruit will start developing again. If bees are not present or inactive, fruit production can be reduced as well. A gardener may notice that some of the fruit that does develop has an uneven shape. This results from poor pollination. The developing seeds inside the cucumber fruit stimulate development of the fruit itself. If only a few of the ovules were fertilized during the pollination process, there won’t be enough developing seed in the fruit to stimulate uniform development of the fruit.

There are some cucumber varieties available now that are gynoecious, meaning that most of the flowers produced are female flowers, so there is the potential for higher yields from these plants. But, those female flowers must still be pollinated with pollen from a male flower. So, some seed from a regular monoecious plant are included in the seed packet so that a supply of pollen will be available for all those female flowers to get pollinated. Parthenocarpic varieties are now also available. These special types of cucumbers can produce fruit without the flowers being pollinated. They are most commonly used in greenhouse cucumber production, where pollination can be a challenge.

There are hundreds of different varieties of cucumber. Here in the United States, they are typically broken down as either pickling or slicing cucumbers, but you may also see some further described as burpless. The pickling types usually produce fruit that is shorter and larger in diameter, but are harvested at an earlier stage of development, from about 2-6 inches in length. The slicing cucumbers are generally smaller in diameter, but harvested at a later stage of development — 4-10 inches in length but usually less than 2 inches in diameter. However, either type can be used for slicing and fresh eating or be pickled. Burpless varieties usually have a thinner skin, a sweeter taste and are easier to digest for most people. Gardeners can now find many other types of cucumbers, heirloom varieties and others from different areas of the world. Some of these vary in color and shape from very long and thin to round.

For more information about cucumbers and the National Garden Bureau, go to http://www.ngb.org.

A Question from Minnehaha County, SD

Do you have some information on growing hollyhocks — kind of fertilizer etc. to use?

Hollyhocks are a popular garden flower that has seen some revived interest in recent years. It will grow best in a full sun location that can also get a little protection from the wind. Most of the old-fashioned types of hollyhock are biennial, which means that if you plant them from seed in your garden, they will usually not flower until the second year. And then, unfortunately, the plants will usually die. But, if you let some of the plants go to seed, you will probably get new plants to grow and start having them bloom every year. Some of the newer varieties are considered perennial, so that they will more often survive for several years. If you remove the flowers right after they are done blooming, this will give the plants a better chance to come back again the next year because they did not use as much of their stored food reserves to produce seed.

Hollyhocks are pretty easy to grow. Probably the best way to get started is to look for potted plants for sale at your local garden center or greenhouse. Plant them in a sunny location, spacing the plants about 12-18” apart. Keep them well watered to help get them established. You can sprinkle a little 10-10-10 fertilizer around the plants and scratch that into the soil, maybe a couple of tablespoons per plant. Or you can use some of the water-soluble plant fertilizers too. Mix it up in a watering can and give them a good drink a couple of times during the summer.

There are few pest problems with hollyhocks, but one of the most common is called hollyhock rust. This disease causes rust-colored blisters to develop along the stems and all over the leaves. It usually does not kill the plants, but certainly makes them look ugly. It is difficult to control with most garden fungicides. Cleaning up all plant debris in the fall will help. But often gardeners decide to completely remove the infected plants and start over with new plants in a different location.

Hollyhocks are an old favorite plant that was a common sight growing along the foundation of most homes years ago. They now come in a variety of flower colors ranging from reds, pinks, whites, yellow and nearly black burgundy. The flowers can also be single or double. They usually bloom in mid-summer and can even be used as cut flowers.