Questions on: Cucumber

Ron Smith, Horticulturist, NDSU Extension Service

Q: In the past, my cucumber plants have not always fared well. I would like enough for pickling, but just get enough for slicing. The leaves either turn yellow or the fruit resembles a ball. There is a tree very close to the garden. Could the tree be giving too much shade or maybe taking most of the nutrients from the garden? Also, last year I grew zucchini for the first time, but the plants stopped growing right after planting. Any advice would be greatly appreciated. (Minot, N.D.)

A: Get your garden soil tested, either at the local garden center or by sending a sample to our soil testing lab at NDSU. No more than a sandwich bag full of soil is needed. There is a nominal charge for the standard test, which includes testing for pH, organic matter content, phosphorus, potassium and soluble salts. Try to plant cucumbers and any other fruit producing vegetable crops in full sun, which means eight hours of direct sunlight each day. Avoid overhead watering. Carefully soak the soil around the base of the plants to avoid disease problems. Bees are being wiped out by mites, so they often are in scarce supply to do the needed pollination. You might want to try a couple of other tactics, such as hand pollinating or planting some borage among the plants in your garden. Borage is one of the best bee attractants in nature. While the bees are working on the borage flowers, they also will pollinate the cucumber and squash flowers. Tree roots and canopies can have a negative impact on vegetable gardening. Evaluate your priorities by determining if you want the tree or the garden. I hope you can save the tree and locate your garden in a sunnier location.

Q: I have had a problem growing cucumbers. I start them out as seeds, but as soon as they get a few inches tall, they fall and start to die. I have tried plant supports for them to grow along or lean in to, but that doesn’t work. Any suggestions? (e-mail reference)

A: The plants need to be started in sterile or pasteurized potting soil, not soil from the outdoor garden. It sounds like they are being wiped out by a common pathogen from a nonsterile media. This is known as "damping-off." Try again, following my suggestions. Don't overwater, provide plenty of light (fluorescent bulbs) and provide a little air circulation over the surface of the plants, using a fan if needed.

Q: The cucumbers that I liked the most this year only had "cucumbers" listed on the nursery stake. I want to have some again next year. How do I dry and store the seeds for sowing next year? I do have a food dehydrator. (e-mail reference)

A: Using a dehydrator is not recommended. Allow the seeds to dry by spreading the seeds on blotting paper or paper towels. Keep the seeds away from humid locations, such as a bathroom or kitchen, and make sure the room has good air circulation. When the seeds are completely dry, put them in a paper envelope, and seal it to keep the seeds cool and dry.

Q: Someone asked me what to do with her cucumbers. Every year the leaves turn brown and eventually the plants dry up without producing fruit. She dug up a spot on the opposite side of her yard but had the same problem. Any suggestions? (E-mail reference)

A: Cucumbers need good drainage and plenty of sunlight. They shouldn't be watered from above. Use a drip irrigation system or very carefully water them with a hose so as to not get any water splashing on the foliage. She should continue to rotate her planting site.

Q: I had a gardener ask me why the blossoms would suddenly fall off his tomato plants. Can you explain that one? Also, why would cucumbers suddenly quit blooming? (Mandan, N.D.)

A: One answer to both questions, high temperatures and a lack of adequate moisture. While both like warm temperatures, the hot weather we've been having and the lack of consistent rainfall will cause both blossom abortion and non blooming. Even our zucchini plants are way down on production this year and that's saying something!

Q: How do you know when cucumbers are ready to be picked? What size do they need to be? (E-mail reference)

A: It depends on the variety of cucumber. That information is on the seed packet. When in doubt, pick early or smaller, rather than larger. The common slicers get about six to eight inches long.

Q: I have a cucumber problem. I have straight 8's that are growing fine but the fruits are only about 2 inches long and about as thick as a pencil. They have been fertilized numerous times. Could over-fertilizing be the problem? (Bismarck, N.D.)

A: Back off on the fertilization. They should thicken up as they mature. Straight 8's are extremely dependable at producing a crop. The bees might not have properly pollinated them this season because of our fickle weather.

Q: This is probably very elementary, but can you tell me if the "old wives tale" about leaving cucumbers on the plant until they turn yellow make the plant quit bearing any more vegetables? Will they no longer produce? (Bismarck, N.D.)

A: That is one tale that has some truth to it. Fruit production will slow and stop if it is not picked on a regular basis. The plant will read that as completing it's life cycle, having set the fruit with the seed within and allowing it to mature. So if you want your garden to continue productivity, keep picking the young tender fruits as they develop and you will be able to extend the harvest beyond just a single picking.

Q: Can you tell me why my mother’s cucumber leaves are turning yellow? (Napoleon, N.D.)

A: She could be overwatering, or she simply could be seeing the cotyledons (seed leaves) drying up, which is natural. As long as the rest of the plant looks normal, she need not worry. If it continues, tell her to give them a shot of nitrogen.

Q: I am growing cucumbers for the first time, and they are getting large, but they are also turning yellowish in color instead of green. Can you tell me why? (E-mail reference)

A: Yellow cucumbers could be the result of planting a yellow fleshed cultivar. Otherwise it could be a virus, too much water or nutrient imbalance. I would suggest picking those that are turning yellow to encourage more fruit set to see if they emerge green.

Q: For the last two years, I have had plenty of blooms and healthy looking vines, but very few cucumbers. Can you tell me why with so many blooms, the production is so low? Out of nine hills, I barely had enough to eat, let alone for canning. The zucchini did fairly well. (E-mail reference)

A: Try another variety or at least a couple of different ones. It may be that you got stuck with a bunch of male flowers that will not produce anything. If the same thing happens again this year, look for the male flower and move it to the female blooms for pollination. The female flowers are the ones with little cucumbers attached. What you are actually seeing is an ovary, the basal portion of the pistil. If this does not get fertilized it withers and dies; if it does it develops into a cucumber. It could also be that you had low pollinating insect activity at the time due to weather conditions.

Q: Last year I planted "Straight Eight" cucumbers in my back yard garden. The cucumbers were bitter. I watered evenly and consistently with the exception of one week that I was away and we did not receive any rain that week. Could there be some type of deficiency in the soil? Should I just try a different type of cucumber? (E-mail reference, Casselton, N.D.)

A: I am sorry to report that it was the dry week that caused the bitterness. Cucumbers need 1 inch of water per week -- every week -- and any water stress results in the fruits being bitter. Straight Eight is a good variety, as I have planted it many time with good success. I would encourage you sticking with that until something else catches your fancy.

Q: I am going to buy some shop lights to start my cucumbers inside and was wondering if it would be better to buy 8-foot bulbs that are 60 watt or 4-foot bulbs that are 40 watt. Does it matter? There is also one called "high output" that is 110 watt.

I was reading in the book "Great Garden Shortcuts" that a good way to start cucumbers is in little plastic pint baskets that strawberries come in. You line it with paper towels or newspaper and then snip off the bottom of the box when planting. I've heard that cucumbers are very touchy when you disturb their roots, and I thought this might be a good idea. What do you think? Would you leave about three plants per box? How many per hill? (e-mail)

A: The shop lights selection would make little difference. You would simply have to have the lower watts closer to the seedlings and run them for a longer time. Generally, the 4-foot bulbs work best, with one being a "cool white" and the other being a "warm white" type. For what you are going to use them for, I would suggest staying with the 40 watt.

Sounds like a good idea with the strawberry baskets. Leaving three per basket and hill would be appropriate. They are fussy about being moved once they have started, so either direct sow or transplant as you have described. Might not hurt to do both to spread the season out a little.

Q: We have a book on all different insects and it talks about if you have aphids that you shouldn't plant cucumbers, pumpkins or squash for one year. We did that but it did not help. This summer we got very few cucumbers. They came up really good and as soon as they started vining out the problem started. The leaves start to curl, get dry around the edges and then the vine starts drying up. We have sprayed and powdered, but nothing seems to help. Do you have any idea what it could be and what can we do about it? Is there something we could put in the garden to get rid of the problem? (Stanton, N.D.)

A: The first thing I would suggest is a soil test which will cost less than $20. Get the pH, soluble salt, organic matter, and the nitrogen, phosphorous and potassium (N, P and K) tested. Send about a pint of soil to NDSU Soil Testing Lab, Waldron Hall, Fargo, ND 58105. Something must be wrong with the soil, I suspect, for the plants to react that way consistently.

Q: With the harvest of garden produce upon us, here is a hint I learned years ago about peeling cucumbers. You may think some cucumbers are more bitter than others. The bitterness is not actually in the cucumber but in the way it is peeled. To prevent it from tasting bitter, peel it from the blossom end toward the stem end. See if you have any more bitter cucumbers. (Fargo, N.D., e-mail)

A: Sounds interesting! I haven't met a cucumber that I didn't like--yet. I never peel my own, eating them more or less like a carrot. I prefer the English Telegraph, a nice long, slender one, about 10 to 12 inches long. It is seedless and has a nice tender taste.

Q: Can you tell me what is wrong with my cucumber and tomato plants? (Pettibone, N.D.)

A: Your plants appear to have the advanced stage of anthracnose and a bacterial leaf spot. First, I would suggest selecting only those plant cultivars that have disease resistance bred into them. Next, continue to rotate your plantings, tomatoes with beans, cucumbers with cabbage, etc. Avoid any overhead watering to keep this from recurring, and spray with a copper-based material to control further spread of the bacterial disease (if it hasn't developed too much). For the anthracnose, try Bravo or mancozeb as a protectant.

Q: All of my squash, gourd, pumpkin, melon, and cucumber plants have begun to die. It begins with one runner wilting and yellowing and then proceeds to the entire plant. There are no bugs, ground rodents etc. visible. Plants have been sprayed and fertilized. The plants are scattered throughout the garden and were not previously planted in current locations. Any ideas? (Avon, S.D., e-mail)

A: It sounds like Verticillium wilt to me. This is a fungus of the root system that attacks plants under the right environmental conditions, and we are seeing a lot of it this year--on cukes, squash, flowers, trees and shrubs. All you can do is remove the dead plants this year, and plant resistant cultivars next year--looking for the initials VFN after the names, which indicates Verticillium, Fusarium, and nematode resistance.

Q: Can you tell me why my cucumber plants are dying? (Marion, N.D.)

A: It appears the cucumbers are being hit by a disease known as verticillium wilt. This soil-borne organism will become active when it comes into contact with susceptible hosts--which it appears your plants are. My only recommendation is to remove the symptomatic plants as quickly as possible. Next year plant the cucumbers in a different location in the garden and be sure to select resistant cultivars.

Q: Is there such a thing as seedless tomatoes and cucumbers? (Carpio, N.D.)

A: Your question is a simple one, but the answers are tough. It took some calls to producers, and here is what I found. There are no seedless cultivars of tomatoes or cucumbers out there, but there are nearly seedless ones.

Your best bet probably is to call companies offering these cultivars. Two such firms are Stokes in New York, at 1-800-396-9238, and Tomato Growers in Florida, at 1-888-478-7333.

Q. I'm not very good at writing letters, but will do my best. I had a vine growing in a flower bed this summer and can find nobody in Williston who can tell me what it is. The vine looks like a cucumber with blossoms. It tastes like a mild cucumber also. Will send sample and a leaf from the vine. Sure hope you can help me. Many thanks. (Williston, N.D.)

A. The plant you sent in is a cucumber, but it doesn't quite know how to look like one! The baseball shape is an indication of something going haywire with the development of the fruit--incomplete pollination, weather extremes, etc. The fact that it showed up in your flower bed could be due animal activity--birds or rodents, most likely. You could also be seeing a second generation from a hybrid cucumber; that would allow for the shape.

Q. Can you tell me if there is something to put on my garden ground before I plant next year? I have blight in my garden. It is on my tomato and cucumber plants.

Enclosed are the leaves. Please let me know what the disease is. (Pettibone, N.D.)

A. The disease is known as late blight or Phytophthora. There isn't much you can do about it now. The best bet next year is to get into crop rotation and avoid overhead or splashing water when irrigating.

I have enclosed extension circular PP-469, "Plant Disease Management in the Home Garden," which will also help you. Others may obtain a copy of this publication at their local county extension office or by contacting the NDSU Extension  Distribution Center, Box 5655, Morrill 10, NDSU, Fargo, ND 58105-5655.

Q: During this summer’s growing season I had a problem with cucumbers. They were slow growing and there were a lot of blossoms but few cucumbers and they tended to curl. I believed there were plenty of bees for pollination since we had a lot of flowers. What product can be used to control blight on tomatoes and other vegetables? I have a dusting power which I have had for some time. It is called "Tomato Vegetable Dust" by Ortho. I cannot find this product now and the closest think I can find doesn’t mention controlling diseases, only insects. Is there a product which can control both insects and certain plant diseases on vegetables and flowers? Also, I have a method of making compost which is to freeze the waste such as vegetable peelings, lettuce, cabbage and things of that nature in milk cartons, then thaw and bury this in the garden. Of course, throughout the growing season, I add other soil nutrients. Is this type of compost acceptable? (Barnesville, Minn.)

A: There is a product called "Home Orchard Spray" which contains both Malathion and Captan that will control insects and diseases. It should be available in any major chain outlets that handle garden supplies or certainly in local garden centers. As for your cucumbers, I’d suggest another variety. Obviously the one you had didn’t like the environment. Your freezing stops the composting action. What you are putting into your garden is not compost by any definition. Compost is a mixture of decomposed vegetable matter, whose constituent parts are not recognizable. What you are adding will eventually become compost, but you can’t call it that now.

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