Cucumbers are a warm-season vegetable planted outside in the ground once the soil is warmed. As plants are frost-tender, it’s very important that you wait until there’s no chance of frost (at least 2 weeks after your last spring frost date).
An easy-care vegetable that loves Sun and water, cucumbers quickly as long as they receive consistent watering. Most varieties will grow in any amount of space, thanks to the plant’s ability to climb.
- Cucumbers are seeded or transplanted outside in the ground no earlier than 2 weeks after last frost date. Cucumbers are extremely susceptible to frost damage; the soil must be at least 70ºF for germination. Do not plant outside too soon!
- Before you plant outside, select a site with full sun.
- Soil should be neutral or slightly alkaline with a pH of 7.0.
- 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.
- 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.
- Plant seedlings one inch deep and about 36 to 60 inches apart, depending on variety. For vines trained on a trellis, space plants 1 foot apart.
- For an early crop, start 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.
- If you live in the cooler climates, you can help warm the soil by covering the hill or row with black plastic.
- Once the ground is warm, mulch with pine straw, chopped leaves, or another organic mulch to keep pests at bay, and 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.
- The main plant care requirement for cucumbers is water—consistent watering! They need one inch of water per week (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 get leaf diseases which will 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.
- Cover seeds with netting or a berry basket if you have pest; this will keep them from digging out the seeds.
- 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 1½ feet apart.
- If you’ve worked in 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.
- Cucumbers may not set fruit because 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 pollinator plants.
- Cucumber Beetles
- Bacterial Wilt
- Mosaic Viruses
- Harvest regular slicing cucumbers when they about 6 to 8 inches long (slicing varieties).
Harvest dills at 4 to 6 inches long and pickles at 2 inches long for pickles. 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.
- At peak harvesting time, you should be picking cucumbers every couple of days.
- Keep them picked. If you don’t, as plants mature, they will stop producing.
- 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.