Why Are My Pumpkin Leaves Turning Yellow?

What do you do when pumpkin leaves turn yellow? Why are my pumpkin plant leaves yellow? Should you cut off yellow leaves from pumpkin plants? Pumpkins are generally easy to grow as long as they get enough sun, have ample room to grow, and get the right amount of water. Pumpkin plant leaves may turn yellow for various reasons, such as age, nutrient deficiencies, infestation with pests, or diseases. In most cases, yellowing leaves are a sign of plant stress. 

Natural causes or Aging of Pumpkin Plant

Sometimes yellow pumpkin leaves don’t indicate a problem at all. At the end of the growing season, when the harvest is ready and the pumpkins are ripe, the older leaves at the base of the crown start to die back.

If the growing season is coming to an end, the yellowing leaves are likely to be part of the natural life cycle of the fruit and so yellowing of the leaves is not a cause for concern. Cutting off the dying leaves can help air to circulate around the plant and stop the rot. 

Older leaves become yellow over time because nutrients like nitrogen will go to the younger leaves where they are needed more. The edges of older leaves may become yellow because they have pores that secrete sap at night, which may have a mildly toxic effect on the edge of the leaves over time. 

Nutrient Deficiency In pumpkins

Yellow leaves could be a sign of a nutrient deficiency and doing a soil test can determine which nutrient is lacking. Pumpkin plants need plenty of nutrients and moist, well-drained soil.

Nitrogen is one essential plant nutrient and if you water the plants too much, this washes nitrogen out of the soil, making it unavailable to the plant. 

Spreading a layer of aged manure around plants without touching the stem helps to preserve the moisture in the soil and give the plant extra nutrients. When watering pumpkin plants, it is important for the ground to be moist but it shouldn’t be sodden. 

Just as much as over-watering pumpkin plants can be a problem, under-watering is not good either. Pumpkins typically need to be watered once a week.

This usually needs to increase to twice a week when the summer heat is at its peak. If the vines and leaves are turning yellow and starting to droop in the heat, they could need some extra watering.

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Pest Attacks and Bug Infestations

A number of different pests such as squash vine borers, spider mites, and whiteflies can cause pumpkin leaves to turn yellow. The pests live on the leaves and stem of the plant, sucking sap from them. When squash vine borers live inside the stem, the plant is unable to take in enough nutrients.

You will find yellowish-brown excrement near the base of the plant because the borers push it out through holes in the stem. Spider mites usually make fine webs under the leaves. Whiteflies are tiny, white insects that fly up in a cloud if disturbed. 

You need to check your pumpkin plants every week for any signs they are being eaten by pests. There are various methods you can use to control pests, such as using different types of sprays – natural or chemical-based. Removing plant debris over winter can also help to control pests and keep them healthy throughout the season.

Diseases In Creppers

Various diseases can cause yellow leaves, such as sudden wilt, downy mildew, or verticillium wilt. When pumpkin roots are infected with sudden wilt, they often turn darker and more straw-colored than healthy roots. Plants die quickly from sudden wilt.

Downy mildew can cause yellow spots on the upper leaves of the pumpkin plant and gray growth on the underside of leaves. Verticillium wilt causes the inside of roots and stems to turn light brown and the crown leaves to turn yellow before the plant eventually dies. 

Summary

To help prevent these diseases, you should rotate your pumpkin to a new growing area every year. Remove plant debris and do not overwater the plants. 

It’s best to water pumpkin plants in the morning so that the leaves have time to dry by nightfall. Never work with pumpkins when the leaves are wet and keep all your equipment sterilized to prevent the spread of disease.