Cucumbers can be a tricky crop to grow for many gardeners. This guide will review the growing needs of cucumbers and some strategies for minimizing pest and disease so you can grow your best cucumbers.
Posts may contain affiliate links, which allow me to earn a commission at no extra cost to you. This helps keep costs down so that I can continue providing high quality content to you for free. I appreciate your purchase through the links! (full disclosure)
Cucumbers are prone to diseases and pests, and may be finicky about soil composition, sun exposure, or the volume of water they have access to. Any of these elements may affect the health of your crop. Here are 12 ways to improve your chances of growing and harvesting an abundance of healthy cucumbers.
1: Encourage Healthy Soil
If you don’t have access to homemade compost or local livestock manure, adding store-bought worm castings to a small garden is a good idea.
Cucumbers enjoy a soil pH between 5.5 and 7. The higher the pH, the less susceptible to fungal disease the plants will be. If your soil doesn’t meet this specification and you really want to grow cucumbers, you will want to look for organic soil amendments that increase or decrease the pH to meet your needs.
Get a soil test to determine whether your garden soil is ideal for growing cucumbers. (If you need some guidance, your local extension office can help you out.)
2: Choose Resistant Varieties
Cucumbers are susceptible to a number of diseases and pests. By choosing varieties that resist disease, you’ll be one step closer to success. The following popular varieties are a few of those currently resistant to bacterial wilt (spread by cucumber beetles), mosaic virus, downy mildew, and powdery mildew.
- Marketmore 76 (slicing cucumber)
- Marketmore 80 (slicing cucumber)
- Salad Bush (slicing cucumber, dwarf–good for containers)
- Regal (pickling cucumber)
For more information, see Cucumber Varieties: Best Bets and Easy-to-Grow.
3: Plant in the Right Place
Cucumbers can be finicky about the amount of sunlight and water they receive. They like heat, moisture, well-drained soil, and evening shade, according to How to Grow More Vegetables.
Because cucumbers are susceptible to mildew, they prefer to be planted on the east side of the garden to access the morning sun. It will effectively dry the dew from the leaves and minimize mildew, according to The Impatient Gardener. Try planting something tall on the west side of cucumbers–such as sunflowers or dill–to provide some evening shade.
Cucumbers like consistent moisture, but they should not be grown where soil remains soggy. Try raised beds if drainage is an issue.
Because cucumbers are so susceptible to pests and disease, it will be important to rotate where you plant them in the garden from year to year. You’ll want to be aware of what was planted in a section before and after cucumbers. For example, melons, pumpkins, and squash are all related to cucumbers, so none of these plants should be planted before or after one another.
You will also want to take care not to plant cucumbers near potatoes or particularly aromatic herbs, according to Carrots Love Tomatoes.
4: Sow Correctly
Direct sow cucumber seeds in the garden once the soil temperature exceeds 60 degrees (Get a soil thermometer!). Although you can start cucumbers indoors and transplant them outside in April or May (depending on location), they tend to be more disease resistant when they are direct sown outside.
Plant a radish seed with every cucumber seed to protect against cucumber beetles, according to Carrots Love Tomatoes. You won’t eat these radishes, but rather let them grow, flower, and go to seed.
If you have had trouble with cucumber diseases in the past, it will be important to give your cucumber plants extra space so the leaves can dry out sufficiently. Plant them 48 inches apart and 1 inch deep.
To avoid the bulk of pest trouble, direct sow cucumbers on the late side of your planting window (usually June-July) to avoid the height of the damage. Or start sowing two weeks after your frost date, and sow continuously every three weeks until eight weeks after your spring frost date.
5: Grow Vertically
Cucumbers are natural climbers, so let them climb! Growing them on trellis netting will allow for better air circulation to minimize disease. A trellis will also make it easier to harvest. Here’s another DIY trellis idea.
While cucumbers like the ability to grow vertically, they will dry out more quickly which can be potentially problematic. Tips #6 and #7 will help remedy that!
Read more: 3 Reasons to Grow Cucumbers Vertically
6: Mulch or Interplant with Companion Crops
Cucumbers are sensitive to weed overgrowth, as weeds can cause crowding, which reduces air flow. Certain types of weeds can also harbor the dreaded cucumber beetle. Mulching the cucumber bed will help keep weeds down while keeping soil moist.
Another way to reduce weeds and keep pests at bay is to interplant rows of cucumbers with rows of companion crops that tend to offer a mutually beneficial relationship. Sweet corn, beans (I like Blue Lake bush beans), peas, radish, and lettuce are a few examples of crops that are said to be cucumber companions.
7: Water Cucumbers Appropriately
Since cucumbers are 99% water, it’s important to not let them dry out, according to The Self-Sufficient-ish Bible. If the leaves show signs of wilting due to dry soil, it is an indication that the plants are stressed, making them more susceptible to pest and disease according to Gardening When It Counts.
On the flip side, it will be important to water correctly, since cucumbers are susceptible to fungal growth if the leaves get wet frequently. Use drip irrigation to keep the leaves dry, or water cucumbers in the morning so they can dry off in the sun throughout the day, according to The Weekend Homesteader.
8: Attract Beneficial Insects and Pollinators
Cucumbers often have difficulty with pollination, which can result in misshapen fruit. Attract beneficial insects and pollinators to encourage good pollination. Sunflower and dill are cucumber companions that encourage pollination. Other perennial herbs could be planted as a permanent border near the cucumber bed. Some examples are tarragon, chives, comfrey, lemon balm, and yarrow.
Create permanent walkways in your garden. Rather than tilling a large area each year, create permanent beds and walkways. Pathways seeded with white clover will attract beneficial insects and pollinators, while pathways of wood chips will encourage beneficial fungal networks in the soil that will control cucumber beetles and the larvae.
9: Repel and Treat Disease
Your first line of defense against disease is prevention. It’s much harder (and usually impossible) to get rid of disease once it pops up.
As mentioned above, cucumbers are susceptible to bacterial wilt (spread by cucumber beetles), mosaic virus, downy mildew, and powdery mildew among others. Follow the other recommendations listed in this article to avoid creating the conditions for a fungal outbreak.
Use anti-fungal solutions to repel and treat fungal outbreaks. Nasturtiums, garlic, oregano, and chamomile are all anti-fungal and will benefit cucumbers when planted near them. Use their cuttings as a mulch.
As a preventative, try spraying plants weekly with an anti-fungal essential oil mixture that includes rosemary, thyme, and other herbs. Spray plants early in the day to protect them from fungal spores.
If you’ve spotted a disease on your cucumber plants (it usually shows up first on the undersides of the leaves), there are a few controls that can help keep it in check. You will probably not be able to get rid of it completely, but you may be able to extend the productive life of your plants.
If your soil is acidic, consider baking soda as a soil amendment that will increase soil pH and reduce the incidence of fungal disease at the same time. Dissolve 1 tsp of baking soda in 1 quart of water and spray on the tops and undersides of the leaves to control powdery mildew according to The Best of Organic Gardening.
A spray of chives or horsetail will dispel downy mildew according to Carrots Love Tomatoes. Horsetail contains 15-40% natural silica, which has long been used to protect against fungal diseases. Measure one ounce of dried chives or horsetail. Boil one quart of water and pour it over the plant matter. Let it cool for 5 minutes, then steep it for four hours. Strain, then dilute the compost tea with one gallon of water.
Alternatively, add 10 drops of horsetail extract to a 32-ounce spray bottle with water. Increase the concentration if you don’t see favorable results.
Read more: Least Toxic Controls of Plant Diseases
Photo via Julie Feinstein @ Flickr
10: Repel and Treat Pests
Adult cucumber beetles eat holes in the leaves, flowers, and stems, and chew on the fruit skin. They can transmit bacterial wilt and mosaic viruses.
Spotted cucumber beetles (Diabrotica undecimpunctata) overwinter in crop debris in the garden and lay eggs in the soil in spring. The larvae (also known as corn rootworm) hatch and feed on plant roots for 2-4 weeks. They produce three generations per year.
Striped cucumber beetles (Acalymma vittatum) overwinter in dense grass and weeds, feed on weed pollen, and then lay eggs. Larvae feed on the roots for 2-6 weeks, producing four generations per year.
The best line of defense against pests is to deter them as much as possible. Healthy plants will be less susceptible to an infestation, so take care to create optimal growing conditions.
Covering cucumber seedlings with floating row cover is the surest way to prevent cucumber beetles. When the plants begin to flower, lift the cover a few hours each morning so bees can pollinate, according to Rodale Organic Gardening Basics: Volume 7, Pests. If using a floating row cover, it will provide decent shade, so planting tall crops nearby won’t be necessary.
Tansy and catnip are said to deter the cucumber beetle, and would be good to have planted nearby. Chop these herbs frequently throughout the season and mulch around the base of the cucumber plants.
For a cucumber beetle infestation, mix one handful of agricultural lime with one handful of wood ash and add water in a 2-gallon watering can or sprayer, according to The Best of Organic Gardening. Spray the leaves of beetle-infested plants. Keep in mind that lime will increase soil pH.
Handpick beetles in the morning when they are slower to fly away and drop them in a pale of soapy water.
If you experience a pest or disease outbreak, it will be important to pull out and destroy or dispose of infested plants at the end of the season. These plants should not be added to your compost bin. Forage chickens in infested beds at the end of the season. They will hunt for beetles or larvae that may be hiding in the soil.
You will also want to take care to rotate crops properly after an infestation by not growing melons, squash, or cucumbers near the area in the following two years.
11: Harvest your Best Cucumbers
Now that you’ve taken such great care of your cucumber plants, it’s time for them to take care of you. Cucumber harvest usually occurs July-October, depending on location. Harvest cucumbers daily when they are six inches long, three inches long for pickling cucumbers. Plants will be more productive if they are harvested often.
Tip: Wear gloves! Prickly spines will hurt!
12: What to do with your Cucumber Harvest
Here’s the fun part!
Try two of my favorite recipes (cucumber chips and cucumber watermelon salad, yum!).
Pickles, of course!
Find more ideas for using and preserving cucumbers in this post.
Have you had success growing cucumbers? What’s your secret to success?