When To Plant Cucumbers – Timing Is Everything!

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Cucumbers are an easy, rewarding summer crop to grow in the garden. With a bit of extra effort, your plants can be healthy and productive all summer and into the fall.

One of the early decisions you need to make is when to plant your cucumber seeds. Your planting date can make or break your cucumber plants and the potential harvest.

So, in this article, you’ll learn exactly when to plant cucumber seeds. I’ll also go into detail about how to plant cucumbers, both indoor and outside, to set yourself up for success. Let’s get growing!

Cucumber seedlings in pots
Cucumber seedlings.

When To Plant Cucumber Seeds

The first thing to understand about cucumbers is that they are warm season crops. They are very sensitive to cold. As a result, the biggest mistake you can make is planting your cucumbers outdoors before the soil has warmed up.

In general, plant cucumber seeds in mid-spring after the soil has warmed to at least 65°F. Additionally, make sure the air temperatures are also warm, no lower than 60°F overnight. These ideal conditions typically come about 3-4 weeks after the last frost date.

Direct sowing vs. transplanting

Cucumbers can be sensitive to root disturbance, so some growers prefer to direct-sow cucumber seeds outdoors. However, transplanting is also possible, but it is important to be careful to avoid damaging the roots.

There are benefits and drawbacks to each method.

  • For direct sowing, you’ll avoid disturbing the roots, but germination can take longer, and you’ll have to wait for the soil to fully warm before planting.
  • For transplants, you can plant seeds earlier indoors, germination is faster, and you can get an earlier harvest.
Direct sowingTransplanting
No root disturbanceMay cause root disturbance
Must wait longer to plantSow seeds earlier indoors
Seedlings can be vulnerable to pestsCan plant other crops before transplanting
Germination may be slowerFaster germination with seed heating mat

For the best of both worlds, you can sow seeds indoors using bio-degradable pots. Then, simply transplant the entire pot into the soil where it will quickly decompose. The roots are minimally disturbed in the process, leading to a seamless transition.

Since cucumbers like it so warm, it is smart to plant early spring crops in the same location before cucumbers are planted outdoors. Some great options include lettuce, spinach, Asian greens, peas, and even brassicas.

My recommendation is to try both direct-sowing and transplanting to see what works best for you. Each gardener’s situation is different, so work with your environment for the best result.

Planting depth and spacing

When you are ready for planting, make sure you are planting at the right depth and spacing. Cucumber seeds should be planted about ½ inch deep, and plants should be spaced about 12 inches apart in rows.

Planting cucumber seeds
Planting cucumber seeds.

For best results after planting, I have some simple tips for growing healthy cucumbers. Learn how to support the plants, keep them healthy, and harvest properly.


Cucumber Growing Tips

Cucumbers can be grown with very little maintenance. However, there are a few tasks you can take care of during the year to maximize each plant’s productivity and health. Learn more about the ideal cucumber growing conditions here.

Trellising

First and foremost, cucumbers are climbing plants. They naturally produce tendrils which latch onto nearby objects, helping the plants stay upright. This vertical growth saves space in the garden while also providing better aeration for the plant foliage, reducing disease and producing straighter fruits.

Cucumber growing on vine

Provide your cucumbers with a trellis to climb up vertically. This can be as simple as a couple of wood stakes with trellis netting stapled between. You can also use a cattle panel to bend a simple archway over a raised bed.

The plants also might need a bit of help climbing up a trellis. Periodically train your cucumber plants to grow in the direction you want, and avoid overlapping branches and foliage.

Pruning suckers

To keep your cucumbers as tidy and productive as possible, pruning is essential. Much like you might do for indeterminate tomatoes, prune cucumber suckers to keep the plant’s energy focused on the main stem.

Suckers are side-shoots that will “steal” energy from the main stem of the plant. It is common practice to remove all but 1 or 2 of these. Learn how to recognize a sucker shoot and remove them while they are still small.

The resulting plants will have 1 or 2 main stems that are producing leaves, flowers, and fruits. This practice keeps your cucumbers tidy and avoids unnecessary crowding.

Harvesting

Perhaps just as important as pruning and trellising is harvesting your cucumbers at the right time. As fruits begin to grow and reach a mature size, harvest them promptly. This encourages your plants to keep producing continually for several weeks or even months.

Cucumber plants climbing tomato cages

If you wait too long and allow fruits to mature on the plant, bad things can happen. First, the fruits may become less appetizing, growing larger and tougher seeds inside. Additionally, the plants may stop producing other fruits altogether, as they focus energy on ripening the existing cucumbers.

Cucumber types

Another consideration to make before planting is the type of cucumber you are growing. There are 3 main types of cucumber plant that can be grown: monoecious, gynoecious, and parthenocarpic.

  • Monoecious varieties grow both male and female flowers, which do not require a separate pollinator. These plants produce fruits with seeds inside, but are the simplest to grow, especially outdoors.
  • Gynoecious cucumbers produce primarily female flowers, which means that a male-flowering variety must be planted nearby for pollination.
  • Parthenocarpic types do not require pollination to grow cucumbers. So, the combination of gynoecious and parthenocarpic is ideal, especially for growing under protective covering (in a greenhouse or tunnel).
Female cucumber flower closeup
Some cucumbers require a pollinator plant to produce fruits.

I recommend growing monoecious varieties or gynoecious and parthenocarpic cucumber types. This may seem complicated, but look for these terms on seed seller websites to know which types you’re planting in advance.

For more information, we have a dedicated article about cucumber types and which are best to grow.


Succession Planting

If you want to take your cucumber growing to the next level, you may want to consider succession planting. This practice is common in market and kitchen gardens, and helps to elongate the harvest window.

In essence, you’ll plant multiple rounds of cucumber seeds, every 2 weeks. Later in the season, the plants will produce their harvests in waves, leading to a more even and consistent harvest over a longer period.

Succession planting is ideal if your goal is to eat your cucumbers fresh, or if you plan to sell them at local farmer’s markets. The intention is to delay the harvest of some of your plants so that you consistently have fresh cucumbers.

On the flip side, for pickling and preserving, you may actually prefer to plant all of your plants at once to get all of your yields at once.


I hope this article helps you determine exactly when to plant your cucumbers in the spring. I love growing cucumbers from seed, as the resulting fruits are so delicious and versatile. Best of luck with your cucumber plants!

– Calvin

As an avid gardener for many years, Calvin is always excited to learn more about the fascinating world of plants. He has a particular fascination with peppers, as well as big, showy flowers like peonies and roses

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