Cucumbers are some of the easiest vegetables you can grow. They grow quickly from seed, or you can go the easy route and get starter plants. With either method, you will need to transplant your cucumber seedlings.
Transplanting is a delicate part of the growing process that should be done at the correct time. So, in this article, I’ll teach you everything you need to know about transplanting cucumbers properly.
When To Transplant Cucumbers
Timing your cucumber transplant is important. Most growers plant cucumbers in small pots, transplanting them out a few weeks after the seeds sprout.
Are the plants ready?
First, your plants should be old enough to be transplanted. Check the roots by gently removing the soil from the pot. If your plants are ready, you’ll see a healthy, well-developed root system.
If you see roots reaching the bottoms and sides of your containers, then your cukes are ready for transplanting. Whether you are moving to a larger pot or into the ground, strong root development is the best sign that they are ready.
Time of year to transplant
If your seedlings are ready for up potting, you should determine the correct time of year to transplant. Cucumbers are warm weather crops, so moving them into the ground too soon can be a big mistake.
We recommend transplanting cucumbers outdoors about 3-4 weeks after your last frost date. Avoid overnight temperatures below 60°F. For example, here in Zone 6A we transplant in early June.
Another method for timing it right is the soil temperature. Cucumbers like warm soil, so only transplant when the soil is at or above 65°F (you can test this with a soil thermometer).
Keep in mind that cucumber vines grow quickly! These plants often reach harvest in a matter of 8-10 weeks from seed. So always wait for the weather to cooperate before transplanting outdoors. Cold weather can ruin your cucumber crop!
How To Transplant Cucumbers
Once you are ready to transplant, now comes the fun part: moving the plants to their new home. While this process is quick, you should be careful to avoid root damage and potential transplant shock.
How to transplant cucumbers:
- Dig a hole the size of your plant’s root ball. You can either dig out a small hole with a garden trowel, or use a shovel handle to press a hole into the soil’s surface. Try to make the hole about the same size as your seedling pots.
- Gently remove the plant from its pot. Cucumbers do not like root disturbance! Gently squeeze the outside of your pots to loosen the soil from the container. Then, tip the pot over to allow the entire rootball to slide out.
- Place the plant into the hole. Avoid handling the roots too much and move the plant directly into the prepared hole. There is no need to plant cucumbers deep like you would tomato seedlings. Instead, plant at the same depth that they were at in their pots for best results.
- Surround with soil and compress. Fill in any air pockets with the surrounding soil and compress firmly.
- Add mulch. Mulch is optional but highly recommended for growing cucumbers. Use leaf mulch, straw, grass clippings, or wood chips to add a thick layer around your transplants. This helps avoid soil borne fungal diseases that are a common problem with cucumber plants.
- Water thoroughly. After planting, water the area slowly and deeply to integrate the seedlings into their new home.
Avoiding transplant shock
During transplanting, your goal should be to barely handle the roots of your cucumbers. These plants are very sensitive to root disturbance, which can lead to transplant shock.
Tips to avoid transplant shock:
- Don’t detangle roots. When you remove the root ball from its container, move quickly to transfer it to its new home. Don’t bother detangling any over-grown roots, as this will do more harm than good.
- Try Cow Pots. Cow Pots (or alternatively, peat pots) are decomposable plant containers. These are made for sensitive-root crops like cucumbers and melons. Instead of removing the rootball at transplant time, you can simply plant the entire pot in the soil and allow it to break down over the growing season.
- Transplant on a cloudy day. If you are moving cucumbers from indoors to outside, it is best to harden off the plants first. If you can’t manage this, transplant cucumbers on a cloudy day to adjust them to the sunlight more gradually.
- Try direct sowing. Planting cucumbers from seed outdoors eliminates the need to transplant all-together! Since most varieties mature in a matter of 8-10 weeks, even cooler climates have plenty of time to reach the harvest window. Wait to sow seeds until after any danger of frost, or until the soil has reached at least 70°F.
If your plants seem to be affected by transplant shock, your only option is to wait for them to recover naturally. However, this stress leads to a weaker plant, making them a good target for pests and disease.
Helpful Tips For Transplanting
When preparing for transplanting day, these common questions may arise. Use these simple tips and tricks to have healthy plants from the start.
How cold can cucumber plants tolerate?
Cucumbers like warm weather and will not tolerate cold well. Wait to transplant outdoors until temperatures won’t fall below 60°F (16°C) overnight.
Why are my cucumber seedlings leggy?
Cucumber seedlings may appear leggy, even if they are healthy. Since they are vining plants, cucumbers tend to have a tall and slender appearance, especially as early seedlings.
If your seedlings are falling over from being too tall, you may need to provide better lighting. Also, a gentle breeze with a fan indoors helps strengthen young cucumber stems.
What is the ideal cucumber plant spacing?
Cucumbers are vining plants, meaning that they like to climb and spread out over time. It is best to space cucumber plants at least 12″ apart for vertical growth, and up to 24″ for the best air circulation.
How many cucumber plants per square foot?
If you are growing vertically (which is recommended, especially for small gardens), you can fit 1 cucumber plant per square foot. If you allow the plants to sprawl along the ground, they will take up much more space in the garden. Plan ahead and provide a trellis or similar for the cucumbers to climb.
How much sun do cucumbers need?
Like most vegetables, cucumbers prefer full-sun conditions. This means at least 6-8 hours of direct, unobstructed sunlight, every day. They may grow in lower light conditions, but expect slower growth and smaller yields.
How to avoid pests early in the season
Cucumber beetles, squash bugs, aphids, and other pests can impact your cucumber plants from a young age. Covering your garden with insect netting is a good idea to protect your vulnerable plants from infestation. Remove this covering once the plants begin to flower.
Trap crops are commonly used to deter striped cucumber beetles from your main food crops. However, if you have an active infestation, insecticide treatment may be necessary to save your harvest.
Should I mulch around cucumbers?
Adding a thick layer of natural mulch around your cucumbers is highly recommended. This has many benefits, including weed suppression, avoiding soil pathogens splashing on the lower leaves, and even adding nutrients to the soil as the mulch breaks down. We recommend leaf mulch, compost, straw, or grass clippings.
Do I need to prune cucumbers?
While pruning cucumbers is not required, don’t be afraid to remove any dead, dying, or diseased foliage during the season. You can also thin out any overly-dense foliage. Excessive leaves can reduce airflow, potentially leading to powdery mildew, downy mildew, and other plant diseases.
What To Plant With Cucumbers
Perhaps just as important as transplanting cucumbers properly is finding the right plants to go along with them in the garden. Here are a few recommended cucumber companion plants:
- Flowers. Flowers are the best companions for the entire veggie garden. They attract beneficial insects, are easy to grow, and some are even edible!
- Garlic and onions. Since cucumbers are best grown vertically, garlic and onions are good plants to grow nearby. These alliums have a small footprint in the garden and can even help deter some critters.
- Dill, thyme, and other herbs. Most herbs are low-growing plants that will not compete for sunlight with your cucumber vines. Fresh dill, rosemary, thyme, and oregano can all be used to make delicious pickles with your harvests!
I hope this article helps you with transplanting your cucumbers successfully. These are some of the most rewarding warm-weather crops to grow from seed in almost any climate!