Cucumbers can be a tricky crop to grow for many gardeners. In this guide, learn how to grow cucumbers organically, including strategies for dealing with pests and disease.
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Ask most gardeners who have grown cucumbers, and chances are their crop has succumbed to a disease or pest at one time. When I see the yellow and black cucumber beetles show up in the garden, my stomach turns. I know I’ll have my work cut out for me to save the crop!
Cucumbers are finicky about soil composition, sun exposure, and the amount of water they have access to. Any of these elements may affect the health of your crop.
Fortunately, I’ve developed a plan for growing the best cucumbers that takes all of this into account! Here are 12 ways to improve your chances of growing and harvesting an abundance of healthy cucumbers.
1: Encourage Healthy Soil
I like to make my own compost (in my compost bin as well as in my worm bin). However, if you don’t have access to homemade compost or local livestock manure, adding store-bought worm castings is one of my favorite store-bought amendments.
They 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, look for organic soil amendments that either increase or decrease the pH.
Get a soil test to determine whether your garden soil is ideal. (If you need some guidance, your local extension office can help you out.)
2: Choose Resistant Varieties of Cucumbers
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 that are currently resistant to bacterial wilt, a disease spread by cucumber beetles.
These varieties are also resistant to 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 Cucumbers 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.
Plant cucumbers on the east side of the garden so they can access the morning sun. Since they are susceptible to mildew, the morning sun will dry the dew from the leaves and minimize mildew, according to The Impatient Gardener.
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, rotate where you plant them from year to year. You’ll also 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.
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4: Sow Correctly
Direct sow cucumber seeds in the garden once the soil temperature exceeds 60 degrees (Get a soil thermometer!). Although cucumbers can be started indoors and transplanted outside in late spring, 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’ve had trouble with cucumber diseases in the past, give your 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. For example, my planting window is typically the last week of April through the first week of June. So I would plant in June. This way, you’ll avoid the height of the damage.
Or start sowing two weeks after your frost date. Sow continuously every three weeks until eight weeks after your spring frost date. This way, if you have some early losses, you’ll still have younger plants coming up later.
5: Grow Cucumbers 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 is to interplant rows of cucumbers with rows of companion crops that 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.
Watering cucumbers is tricky, however, 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
First: Repel 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, 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 antifungal solutions to repel and treat fungal outbreaks. Nasturtiums, garlic, oregano, and chamomile are all antifungal and will benefit cucumbers when planted near them. Use their cuttings as a mulch.
As a preventative, spray plants weekly with an antifungal essential oil mixture that includes rosemary, thyme, and other herbs. Spray plants early in the day to prevent fungal spores.
Second: Treat Disease
Look regularly on the undersides of leaves for disease. If you spot something, there are a few things you can try. You may not be able to get rid of it completely, but you can extend the productive life of your plants.
If your soil is acidic, baking soda can increase soil pH and reduce 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 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 herb. Boil one quart of water and pour it over the plant matter. Cool for 5 minutes, then steep it for four hours. Strain, then dilute the compost tea with one gallon of water.
Alternatively, add one to three scoops of horsetail powder to a 32-ounce spray bottle with warm water and shake to dissolve. May need to strain through cheesecloth to avoid clogging the sprayer. 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
First: Repel 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 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. Learn more about the life cycle and habits of bumble bees!
A floating row cover provides sufficient shade, so planting tall crops nearby won’t be necessary.
Tansy and catnip are said to deter the cucumber beetle, so plant them nearby. Alternatively, chop these herbs frequently throughout the season and mulch around the base of the cucumber plants.
Second: Treat Pests
For a cucumber beetle infestation, mix one handful of agricultural lime with one handful of wood ash in a 2-gallon watering can. Then add water, 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 and drop them in a pale of soapy water.
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. Allow chickens to forage in infested beds at the end of the season. They will hunt for beetles or larvae that may be hiding in the soil.
Rotate crops 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 in late summer to early fall. With all the care that’s gone into growing your best cucumbers, harvest at the peak of freshness!
Plants will be more productive if they are harvested often. Harvest cucumbers daily when they are six inches long, three inches long for pickling cucumbers.
Tip: Wear gloves! Prickly spines will hurt!
12: What to do with your Cucumber Harvest
Here’s the fun part!
- Granny’s Bread and Butter Pickles
- How to Make Kosher Dill Pickles
- 4 Ways of Preserving the Harvest
- Cucumber Mint Jam
- Cucumber Picante Sauce
- Are Raised Beds Right for You?
- Grow These Low Maintenance Crops
- Storing Seeds for Long-Term Seed Saving
>>> Get my free 19-page Guide to Organic Soil Amendments for more ideas:
Have you had success growing cucumbers? What’s your secret to success?