My dad called me a few weeks ago with a cucumber question. His vines were growing well, looked healthy and had a lot of flowers, but he could see only one tiny cucumber.  He had noticed that he doesn’t have a lot of bees this year and thought perhaps that was the problem. 

The answer I found to his query was a real surprise. According to the UC Davis Research and Information Center, on a normal cucumber plant (Cucumis sativus), the first 10 to 20 flowers are male. For every female flower, which yields the fruit, the plant produces 10 to 20 male flowers. 

Before the outnumbered female flower develops into a cucumber, the pollen must be carried from male to female. Normally bees do this job, but other pollinating insects, or even a gardener with a tiny brush, can step in.

How can you identify a female flower? Look for the one with a tiny swollen pickle on the end. That’s the flower that must be pollinated to produce a fruit big enough to slice for your salad.

Plant breeders knew that a vine with more female flowers would produce higher yields. So they bred some new varieties that have a greater proportion of female flowers, and others that produce only females. As a result, some modern varieties bear fruit earlier and have higher yields than “normal” cucumbers. The vines with all-female flowers can be grown in greenhouses without pollination; consequently, the fruit they produce is seedless. If they are pollinated, seeds will form. 

Many gardeners complain about bitter cucumbers. Bitterness can be traced to two terpenoid compounds, controlled by two genes. One, a dominant gene, promotes bitterness; the other, a recessive gene, inhibits it.

Bitter compounds are usually concentrated at the cucumber’s stem end, as well as in the skin and just underneath. Contrary to one belief, you can’t affect the bitterness by how you peel the fruit.

The so-called “burpless” cucumbers are slender, long and thin-skinned. Through careful plant selection and breeding, most of the bitterness associated with indigestion has been removed. But any cucumber can develop bitterness if the temperature fluctuates more than 20 degrees, if the plant is water stressed, or if the cucumbers are stored near other ripening vegetables after harvest.

Cucumbers come in many varieties, from large slicing varieties for eating fresh, to pickling types, to tiny cornichons. The University of California recommends varieties  that do well in our area and are bred for disease resistance and minimal bitterness. 

Among pickling cucumbers, the university recommends Pickling, Liberty Hybrid, Saladin, County Fair 83 and two types, Pickle Bush and Pot Luck, that do well in containers.

Slicing types recommended for our area include Dasher 11, Sweet Success, Sweet Slice (burpless) and, for containers, Pot Luck, Salad Bush, Parks Bush Whopper and Spacemaster.

Remember that most cucumber vines are sprawlers, making it difficult to weed or work in the rows without damaging the plants. Consider training the vines on a cage, trellis or fence to keep the fruit off the ground, save space and avoid damage when harvesting. If vines are not trellised, gently roll the vines rather than lifting them when looking for harvestable fruit to avoid destroying the blossoms or kinking the vines.

Avoid growing cucumbers in cool or shady locations, water regularly, and provide ample nutrients.

Harvest cucumbers before they begin to turn yellow. Remove fruits by twisting them and giving a quick snap. This prevents vine damage and results in a clean break.

While many cucumbers have been bred for disease resistance, they can still be plagued by aphids, spider mites, leaf hoppers and mildew. If you suspect you have any of these problems, call or come into the Master Gardener office for information on cucumber culture and advice on solutions.

Napa County Master Gardeners (http://cenapa.ucdavis.edu) answer gardening questions Monday, Wednesday and Friday, 9 a.m. to noon, at the UC Cooperative Extension office, 1710 Soscol Ave., Suite 4, Napa, 253-4221, or

877-279-3065.