Cucumber plants wilting after transplant is a common problem.
But it’s usually easy to work out what’s causing it.
And sometimes, you can save the plant and return it to good health.
In this article, I’ll help you with that.
And if the plant can’t be saved, at the very least you’ll know what to avoid to make sure it doesn’t happen in the future.
Let’s dive in.
Cucumber Plants Wilting After Transplant: The Causes
There are a number of things that can cause your cucumber plants to wilt after transplant.
The most common are:
- Damage while transplanting them
- You didn’t harden them off
- Too much fertilizer added
- Too much water
- Too little water
- Diseases and pests
To solve the problem and stop your cucumber plants wilting you need to identify which one—or more—is affecting your plants.
So we’re going to take a deeper look at each of these in turn, to show you why they cause your cucumber plants to wilt and what you can do about it.
Damage During Transplant
If you’re not careful, it’s very easy to cause damage while transplanting. And this often leads to cucumber plants wilting.
The first type of damage to be aware of is root damage.
This often happens when people move plants outdoors. Particularly when the plant already has a well-established root system.
Another common problem is the tangling together of root systems when plants are grown indoors in overcrowded conditions. When separating them, make sure you do it gently to avoid damage.
To stop this problem occurring, try thinning your seedlings after germination.
When seedlings are allowed to grow with sufficient space you prevent their roots from tangling together. You also make sure they all have sufficient access to nutrients and water. And another benefit is reducing the incidence and transmission of disease.
When transplanting, some people make the mistake of shaking and brushing off the soil that’s clinging to the roots. This is unnecessary, and can lead to you accidentally cause them harm.
The roots aren’t the only part of the plant that you might have damaged.
Take a look to see if the plant’s vines have suffered any injury. It’s easy to see if they have become broken or bent.
Damage to the vines can cause all of the leaves connected to it to wilt. If the damage is severe enough, it could cause the plant to die.
Hardening off is the process of slowly letting your cucumber plants adjust to outside conditions.
Because your seedlings have been growing indoors they won’t have been exposed to the cold, heat, wind, rain, and insect pests that they are suddenly assaulted with when you transplant them outside.
The variability in environmental conditions can be a shock for young plants and could be the reason why they are wilting.
To avoid cucumber transplant shock caused by a sudden introduction to outdoor conditions, consider placing them in a greenhouse first to let them harden off. This will help to keep them warm even if it’s cold at night.
Another way of doing it is to place the young plants outside during the day when it’s warm and bring them back in at night when temperatures drop.
Choose a shaded part of your garden that’s protected from the wind. Each day, try to give them a bit more exposure to the sunlight.
It’s best to begin the process of hardening off your plants a couple of weeks before you intend on moving them permanently outside.
When you do transplant them outdoors, try to do it in the evening or late in the afternoon. This gives the plants a bit of time to adjust to the new conditions before they face the sun the next day.
As you transplant them into the ground, don’t leave them with their roots exposed to sunlight. Move each plant from the pot, tray, or container it’s been growing in, and place it straight into the hole you’ve prepared in the soil.
Because of the difficulties of transplanting cucumber plants without causing damage to them, many gardeners actually prefer to plant cucumber seeds into the ground outside rather than starting them off indoors.
But if you live in an area with a colder climate that only has a short growing season, this isn’t always possible. Your plants will die if they experience frost, which can still happen in the spring in some places.
When moving them outside, don’t do it when nighttime temperatures are below 50°F, as this can cause the cucumber plant leaves to wilt and become discolored.
Even temperature drops below 60°F can cause problems, and it’s recommended to wait until the soil temperature is at least this high before you transplant cucumber plants.
Too Much Fertilizer
Be careful when adding fertilizer straight after transplant. Too much causes fertilizer burn and will result in wilting leaves.
Fast-release fertilizers are more problematic, especially if you didn’t sufficiently water your plants.
Instead, consider using a slow-release fertilizer that will break down gradually over time, slowly releasing fertilizer into the soil for root uptake.
Organic fertilizers tend to be a good choice for this. But you can also get synthetic fertilizers in slow-release pellets or granules.
Too Little Water
Underwatering is a common cause of cucumber plants wilting.
It’s a natural mechanism that the plant uses to minimize water loss due to evaporation during periods of drought.
It does this by reducing the surface area of the leaves that are exposed to sunlight and the movement of air.
If your plants suffer without water for too long you may notice the leaves drying up and becoming crispy. At this point the situation is critical, and you have to act quickly to save them.
Fortunately, the solution is simple.
Too little water is more likely to be a problem if you’ve transplanted your cucumber plants into soil that’s fast draining. Or if your climate is hot, dry, and sunny.
Too Much Water
Unfortunately, some people go too far with watering their plants, and this causes problems as well.
Cucumber plants don’t like growing in waterlogged soil. It prevents the roots from absorbing oxygen and can eventually lead to fungal infections and root rot.
The damage done to the roots then makes it more difficult for your plants to absorb enough water. Leading to dry and wilting leaves.
Water the plants 1-2 times per week. Wait until the top inch of soil is dry each time before you water.
If your cucumber plants are growing in a container it should have decent sized drainage holes that allow the water to run easily from the bottom.
Diseases & Pests
Depending on how soon after planting you start seeing problems you may want to consider diseases and pests as a cause.
If wilting occurs immediately after transplant, it’s unlikely there’s been enough time for this to be the explanation.
But there are a number of diseases and pests that can cause your cucumber plants to wilt.
Of these, the most common is bacterial wilt.
This is spread by cucumber beetles. And it causes your cucumber leaves to turn yellow and wilt.
If your plants have those symptoms, you can confirm the cause by finding the cucumber beetles.
They’re easy to spot on a leaf. They’re about a ¼ of an inch long and are bright yellow with either striped or spotted black markings.
Because there’s no good treatment for cucumber plants infected with bacterial wilt it’s best to remove them from your garden once you identify this disease as the cause. The only way to stop the disease from spreading is to stop the beetles.
Other pests that feed on your plants and lead to cucumber plants wilting include the squash bug and the squash vine borer. Although they prefer feeding on squash plants and pumpkins, they will spread to cucumbers if you’re growing them nearby.
The Squash Bug
Squash bugs suck out the sap from the inside of the leaves, and do the most damage to young plants and cucumber seedlings.
Yellow spots that turn to brown show the locations of their feeding. And the leaves of the plant start to wilt.
You can identify them by their gray or brown body with striped edges. They grow to around ⅝ inches.
Hand-picking them off your plants can keep the numbers down. But be careful not to let them grow into an infestation, because then it’s a difficult problem to get rid of.
Neem oil or horticultural soap can help you if you need them.
Squash Vine Borer
Adult squash vine borer photo by Lisa Brown
Squash vine borer adults are easily visible. They look similar to wasps and have bright orange abdomens with black dots.
But the damage is caused by their larvae. They will bore into the stem of your plants. Once there, they block the passage of water and nutrients from moving around the plant as they feed on its insides.
Cucumber plants wilting and yellowing of the leaves quickly follows, with the plants eventually dying.
It’s difficult to save infected plants. But if you suspect you have squash vine borers in your garden you can try sprinkling a pesticide such as carbaryl around the base of your cucumber plant stems.
Many diseases that affect vegetable plants are spread by water or through the soil. As some cucumber plants grow along the ground, this makes them more susceptible.
So try using some form of vertical support to make them grow away from the ground, such as a trellis.
Or you can grow a bush variety of cucumber that doesn’t need the support.