There are several reasons cucumber seedlings die.
A main reason is bacterial wilt. This causes your cucumber to have droopy leaves all the time. Bacterial wilt is caused by cucumber beetles where the Erwinia tracheiphila bacterium is found.
The spread is gradual, and you may think it is just a natural occurrence for some parts of your cucumber to wilt during the day, but you will notice that your cucumber seedling is generally wilting, and this shows that the infection has spread on the entire plant.
Another reason you should consider why your cucumber seedling is dying maybe because of over-watering. Cucumber seedlings require watering, especially during summer, and when it is hot outside.
It will have the same effect whether your plant lacks water or if it is waterlogged. If you check the soil and it is dripping with water, you may be watering it too much. If the soil is dry when you pinch it, then it lacks water and is slowly drying.
Reasons To Consider When Your Cucumber Seedling Is Dying
Examine if your plants have holes in them, or there are missing parts on the leaves. An indication that something is feeding on them. The usual culprit is cucumber beetles, they are tiny, small, and have a voracious appetite. They can feed on your cucumber plant, and this can start its destruction.
Not only do they spread Wilt Disease, but they are highly damaging to cucumber plants.
Whiteflies are also harmful to cucumber plants cause they feed on the leaves and lay their eggs on the undersides of the leaves. They only not feed on the leaves, but they also suck on the plant sap causing it to turn yellow.
The best way to treat your cucumber plant is to spray it with an insecticide that can kill both pests mentioned.
Wrong Soil Temperature
If the soil is too hot or too cold, your cucumber seedling will have a hard time germinating, and it can slowly die. The ideal temperature of soil should be between 65 to 75 degrees Fahrenheit.
The chilly air and the soil that is too cold will not help your cucumber seedling to germinate. A bottom heat source should be used for stony soil.
Incorrect Depth During Planting
If you plant the seeds too shallow, then too much light can get to them, and they will not grow. When you plant your seeds too deep, they will also not germinate as the sunlight can’t reach them.
This is the type of disease that can affect the growth or the germination of your cucumber seeds. It occurs when the condition of the soil is too wet or overly soaked in water. The pathogen will thrive on such soil conditions and kill the seeds before they can even grow.
Other causes of this disease include poor soil drainage, less air circulation, dirty pots or containers, cold and wet soil.
Moss or Mold
When your seeds are planted in a container and left soaked in water, this may cause moss and mold to appear. Your cucumber seedlings can slowly die with the appearance of such.
The water will rot the roots of your cucumber, and it will not grow at all. Once it is also matched with no sunlight, there is no way for the soil to drain or for the water to evaporate.
Presence of Cutworms
Cutworms can eat away on the stems, roots, and leaves of your cucumber. You will see these pests curled and hidden under the soil and slowly eat away your cucumber seedlings, and there won’t be any growth soon for your cucumber.
The cucumber seeds may be too far from sunlight or any light source. Sunlight is required for the growth of your cucumber. When you don’t place them where they can enjoy the sunlight, they will have difficulty germinating. The soil is also prone to different bugs and pests.
Too Much or Too Little Fertilizer
There is also fertilizer burn when you add too much fertilizer to your cucumber seedling and when you do this often. The best way is to feed them fertilizer when you plant them in a container or directly into the soil and then not to follow it up for a time.
If the soil is also deficient in nutrients, it can stop the growth of cucumber seedlings. The soil may not have the proper mix of nutrients, and you have to supply the needed fertilizer, so the cucumber seedlings will continue to grow.
When you place too many seedlings in one area or a container, you are not helping your cucumber seedling to germinate fast. The seeds will fight to survive and may lead to wilting or dying in the long run.
Such soil quality will have lack air space and have poor drainage. There is no space for water to exit, and it will just soak the soil leading to rotting seeds in the long run.
Just like having the plants away from sunlight can cause them to wilt or die, excessive sunlight can also cause damage to your cucumber seedlings.
Too much sunlight can dry the seeds and induce stunted growth, or the cucumber seedlings die slowly in the process.
The provision of sunlight should be for 12 to 14 hours, and there should be a rest period for your cucumber seedlings.
Presence of Fungus
There is also fungus that can grow on your cucumber seedling before they can even germinate. The appearance of white, powdery film in your plant is a sign that there is fungus thriving on it and will suck the nutrients from your young plant.
Even if your cucumber seedlings grow, they will have poor growth and no longer sturdy.
The best way to fight off such fungus or mildew is by using neem oil on the surrounding soil. Ensure that you do not apply the oil when it is scorching outside and wait for a temperature below 80 degrees Fahrenheit before application.