Posted On April 6, 2020
An easy-care vegetable that loves sun and water, cucumbers grow quickly as long as they receive consistent watering and warmth. Most varieties will grow in any amount of space, thanks to the plant’s ability to climb. Of course, these prolific veggies are perfect for pickling!
There are two types of cucumber plants: vining cucumbers and bush cucumbers. The most common varieties grow on vigorous vines shaded by large leaves. The growth of these plants is fast, and the crop yield is abundant if you care for them properly. Vining varieties grow up a trellis or fence. They will be cleaner—versus those that grow atop soil—often more prolific, and easier to pick.
Bush cucumbers, however, are nicely suited to containers and small gardens. Make successive plantings (every two weeks for continued harvests). In already-warm summer soil, cucumbers will grow quickly and ripen in about six weeks!
If you’re interested in making pickles, we recommend several prolific varieties below that are bred especially for pickling, such as heirloom ‘Boston Pickling’. For crispy pickles, be sure to prepare them within a few hours of harvesting!
When to plant cucumbers
- Cucumber plants should be seeded or transplanted outside in the ground no earlier than 2 weeks after the last frost date. Cucumbers are extremely susceptible to frost and cold damage; the soil must be at least 70ºF for germination. Do not plant outside too soon!
- To get a head start, sow cucumber seeds indoors about 3 weeks before you transplant them in the ground. They like bottom heat of about 70ºF (21ºC). If you don’t have a heat mat, put the seeds flat on top of the refrigerator or perch a few on top of the water heater.
Choosing and preparing the planting site
- Select a site with full sun. Cucumbers need warmth and lots of light.
- Cucumbers require fertile soil. Mix in compost and/or aged manure before planting to a depth of 2 inches and work into the soil 6 to 8 inches deep. Make sure that soil is moist and well-drained, not soggy and compacted.
- Soil should be neutral or slightly alkaline with a pH of around 7.0.
- Improve clay soil by adding organic matter. Improve dense, heavy soil by adding peat, compost, or rotted manure. (Get a soil test if you are unsure of your soil type; contact your local county cooperative extension.) Light, sandy soils are preferred for northern gardens, as they warm quickly in the spring. See our guide to soil amendments.
How to plant cucumbers
- Plant seeds 1 inch deep and about 2 to 3 feet apart in a row, depending on variety (see seed packet for details). For vines trained on a trellis, space plants 1 foot apart.
- Cucumbers can also be planted in mounds (or “hills”) that are spaced 1 to 2 feet apart, with 2 to 3 seeds planted in each mound. Once plants reach 4 inches in height, thin them to one plant per mound.
- If you live in the cooler climates, you can help warm the soil by covering the hill or row with black plastic.
- After planting, mulch around the area with straw, chopped leaves, or another organic mulch to keep pests at bay, and also keep bush types off the ground to avoid disease.
- A trellis is a good idea if you want the vine to climb, or if you have limited space. Trellising also protects the fruit from damage from lying on the moist ground. See how to build a trellis and support for vining vegetables.
- Cover freshly planted cucumber seeds with netting or a berry basket if you have pests; this will keep them from digging out the seeds.
How to grow cucumbers
- The main care requirement for cucumbers is water—consistent watering! They need at least one inch of water per week (or more, if temperatures are sky-high). Put your finger in the soil and when it is dry past the first joint of your finger, it is time to water. Inconsistent watering leads to bitter-tasting fruit.
- Water slowly in the morning or early afternoon, avoiding the leaves so that you don’t encourage leaf diseases that can ruin the plant. If possible, water your cucumbers with a soaker hose or drip irrigation to keep the foliage dry.
- Mulch to hold in soil moisture.
- When seedlings emerge, begin to water frequently, and increase to a gallon per week after fruit forms.
- When seedlings reach 4 inches tall, thin plants so that they are at least 1½ feet apart.
- If you’ve worked organic matter into the soil before planting, you may only need to side-dress your plants with compost or well-rotted manure.
- If you wish, use a liquid fertilizer from your garden store such as vegetable plant food which is low nitrogen/high potassium and phosphorus formula. Apply at planting, 1 week after bloom, and every 3 weeks, directly to the soil around the plants. Or, you can work a granular fertilizer into the soil. Do not over-fertilize or the fruits will get stunted.
- If you have limited space or would prefer vertical vines, set up trellises early to avoid damage to seedlings and vines.
- Spray vines with sugar water to attract bees and set more fruit.
- Little or No Fruit:
- If your cucumber plants do not set fruit, it’s not usually a disease. There is probably a pollination issue. The first flowers were all male. Both female and male flowers must be blooming at the same time. This may not happen early in the plant’s life, so be patient. (Female flowers are the ones with a small cucumber-shaped swelling at the base that will become the fruit.)
- Lack of fruit may also be due to poor pollination by bees, especially due to rain or cold temperatures, or insecticides. To rest assured, you could always hand pollinate. (Dip a Q-tip into the male pollen and transfer it to the center of the female flower.)
- Remember, gynoecious hybrids require companion pollinator plants.
- Squash bugs may attack seedlings.
- Aphids are always a nuisance for any vegetable plant but easily managed.
- Powdery mildew can be a problem if the leaves get wet (water at the soil level). Apply fungicides at the first sign of its presence.
- Cucumber Beetles may attack the vines and can cause disease.
How to harvest cucumbers
- Don’t let cucumbers get too large or they will taste bitter.
- At peak harvesting time, you should be picking cucumbers every couple of days. They’ll grow quickly!
- Harvest regular slicing cucumbers when they about 6 to 8 inches long (slicing varieties).
- Harvest dills at 4 to 6 inches long and pickling cucumbers at 2 inches long.
- The large burpless cucumbers can be up to 10 inches long and some types are even larger.
- Cucumbers are best picked before their seeds become hard and are eaten when immature. Do not let them get yellow. A cucumber is of highest quality when it is uniformly green, firm, and crisp.
- Any cucumbers left on the vine too long will also get tough skins and lower plant productivity.
- How to pick? Using a knife or clippers, cut the stem above the fruit. Pulling the fruit may damage the vine.
- Keep them picked. If you don’t, as plants mature, they will stop producing.
How to store cucumbers
- Cucumbers are over 90 percent water. Store wrapped tightly in plastic wrap to retain moisture.
- They will keep for a week to 10 days when stored properly in the refrigerator.
- ‘Burpless Bush Hybrid’ is a popular bush form of cucumber.
- ‘Boston Pickling’ is our favorite heirloom variety bred especially for pickling.
- We also recommend disease-resistant ‘Sassy’ or ‘Calypso’ for early yields.
- Long, thin ‘Parisian Pickling’ is great for making gherkins or cornichons.
- Lemon cucumber is a smaller cucumber many folks find reliable.