When it comes time to harvest cucumbers, a few problems can rise. Here are some questions and answers from horticulturists at Iowa State University Extension and Outreach.
To have additional questions answered, contact the ISU Hortline at 515-294-3108 or at email@example.com.
Q: When should I harvest cucumbers?
A: Pick them promptly when they reach the desired size — every two to three days. If you don't, they may be monsters by the next time you visit the garden.
Pickling cultivars should be harvested when the fruits are two to four inches long.
Slicing cucumbers should be six to eight inches long and 1 ½ to 2 inches in diameter, but still dark green and firm.
Over-mature cucumbers left on the vine inhibit additional fruit set.
Q: Why are some of my cucumbers misshapen?
A: Poorly shaped fruit are usually the result of poor pollination, and poor pollination may be due to cool, wet weather and improperly applied insecticides that limit bee activity. When insecticides are necessary, select an insecticide with a low toxicity to bees and apply it early in the morning or late in the evening to reduce the risk to bees.
Q: Why are some of my cucumbers bitter?
A: Bitterness is produced by the compound cucurbitacin, normally found in the leaves, stems and roots of cucumber plants. The cucurbitacins spread from the vegetative parts of the plant into the cucumber fruit when plants are under stress. Hot, dry weather is usually responsible for bitterness in cucumbers in the Midwest.
Cucurbitacins tend to be concentrated in the stem end of the cucumber and just under the skin. To eliminate most of the bitterness, cut off the stem end of the fruit and peel the remaining portion of the cucumber.
To avoid this problem in the first place, try planting bitter-free cucumber cultivars, such as ‘Sweet Slice’ and ‘Sweet Success.’ Watering cucumber plants once a week during hot, dry weather may also be helpful.
Q: Some of my cucumbers rot at the blossom end. Why?
A: The rotting is probably due to blossom-end rot that is a physiological disorder that occurs on tomatoes, peppers, eggplants and cucurbits. On cucumbers and other vine crops, the blossom-end of the fruit begins to rot and within a short time the entire fruit has rotted.
Blossom-end rot is caused by a lack of calcium in the developing fruit. In most cases, there is no need to apply calcium to the soil. Try to maintain an even moisture supply by watering once a week during dry weather. Also, do not over-fertilize plants. Uneven moisture supplies and excessive nitrogen inhibit calcium uptake.