Everyone’s favorite fall fruit is the pumpkin. From pumpkin pies to pumpkin spice lattes, these orange gourds are having a serious moment. While simple to grow in theory, you may still run into issues with growing pumpkins at home.
Some of the top problems encountered when growing pumpkins are foliage-hungry pests like cucumber beetles and squash-vine borers. Powdery mildew and other bacterial infections can also attack pumpkins. Check your pumpkins for pests daily and treat them with an antifungal agent to fight infections.
Read on to learn everything about the top problems growing pumpkins and how to fix them. In the following article, we will answer all of the questions you may have about growing pumpkins. We will address issues like:
- pumpkin plant turning yellow
- pumpkin rot on vine
- pumpkin plant not growing
- pumpkin plant not producing
- pumpkin ants
- pumpkin leaves burning
- pumpkin frost tolerance
Are your pumpkins dying for seemingly no reason? Let us take a closer look at what might be happening.
A pumpkin that is dying is often having an issue with water; either it is getting too much or too little. If your pumpkins are getting too little water, the first sign will usually be yellowing or wilting leaves. The leaves are vital to the patch’s success, growing broad and fanning above the top of the gourd. These leaves shade the fruit from the summer heat, protecting them from burning and preventing their roots from drying out.
If your pumpkin is getting too little water, the leaves will die first. After this, the fruit will start to wilt and die. You can combat this by providing the plants with a healthy soaking twice a week until the leaves have some strength. Further aid the plant’s recovery by supplying the pumpkin patch with a shade source while the leaves re-grow.
If your pumpkin is getting too much water, you may not notice until the pumpkin becomes soft and squishy, at which point it is likely too late to save them. The best chance you have of recovering your pumpkin patch at this point is to remove and discard any of the affected pumpkins. Hopefully, the moisture has not affected all of the pumpkins yet, and you can still save some of them.
You will have to reassess your watering practices as well. Once a week should be enough for your pumpkins until the peak of summer, when you may need to water twice a week.
Pumpkin Plant Turning Brown
There are a few different reasons why your pumpkin is turning brown.
If the cucumber beetle has infested the plant, it could easily have been infected by a harmful bacteria known as Erwinia tracheiphila. This bacteria causes bacterial wilt, which attacks the stems and vines of the plant.
The vines clog and eventually wilt, turning brown in the process. The best offense for bacterial wilt is a good defense against the cucumber beetle. Use a carbaryl-based pesticide to defend your garden.
Another infection–this time fungal–can cause ugly spots on your pumpkins. Alternaria blight attacks the pumpkins by causing them to mold and rot. You will likely spot this attack because of the brown and black spots that will spread across your pumpkins.
You can defend against the Alternaria cucumerina fungus by treating your plants with fungicides that contain captan and thiram. However, if your crop is attacked, it is unlikely you can save it, and you will have to clear the garden completely so next year’s plants do not die, too.
Pumpkin Plant Turning Yellow
Pumpkin plants that turn yellow are almost always under-watered. This effect is most likely to occur in the summer when the heat is at its peak. On average, pumpkins only need to be watered once a week; this need increases to twice a week when the weather is scorching.
If you notice the vines and leaves of your plant are turning yellow and look sad (aka, visibly drooping), then you should give the plant a few weeks of generous watering to help combat the drought. You can also remove the leaves that have turned completely yellow, especially if they have started to shrivel up. Eventually, these shrivelled leaves will turn brown and fall off completely, so you can remove them if you wish.
Pumpkin Rot on Vine
A pumpkin rotting on the vine is likely suffering from a fungal or bacterial infection. These dangerous diseases are prone to occur in warm, wet weather. The moisture will sit on the pumpkin’s surface and soak into the soil beneath it, while the warm temperatures promote the growth of these harmful bacteria.
If you live in a very humid or rainy area, you can help combat this by elevating your pumpkins’ fruit slightly off the ground. By lifting the gourds just a little, you remove a lot of the surface contact between the damp earth and the fruit.
Pumpkin Plant Not Growing
A pumpkin plant that doesn’t develop fruit is likely a plant that was not successfully pollinated. These plants grow their long vines first, laying a path for the bountiful fruit to appear, but first, male and female flowers shoot up, which require pollination by bees.
The male flowers bloom first, tempting the bees to add the pumpkin plant into their daily routine. One to two weeks later, the female flowers arrive, and the plant is ready to be pollinated. If there are no bees in the area, the plant will not be pollinated, and no fruit will be produced.
Similarly, if the weather is too hot too early in the summer, the female flowers will hold off on blooming. The window for pollination then becomes shorter, and the plant may fail to produce and fruit.
The situation can also occur where the plant will begin to form fruit, but the tiny gourds will be aborted. The plant sometimes does this when stressed, preserving the health of the vines above the fruit.
Hot weather, cold weather, extreme humidity, and nearby pests can cause the plant to get stressed and drop its fruit before it grows to a reliable size. Help defend your plants by providing extra water on the hottest days and laying a plastic sheet over them on the coldest nights.
Pumpkin Plant Turning White
Powdery mildew is an extremely common plight of pumpkin plants. This infectious mildew is quick to spread and produces a white layer of powder across your plants. In particular, the pumpkin leaves are affected, which can give your garden a ghostly appearance. It may sound perfect for Halloween, but this spooky stuff can kill your pumpkins if left unchecked.
The best way to combat powdery mildew is by combating it with either neem or jojoba oil. These plant-based oils are excellent warriors in the battle against powdery mildew. Apply the oil to the affected areas, and they will set to work to disinfect your pumpkin plants. Natria Neem Oil is an easy-to-apply product that can save your pumpkins if they have been turning white.
Pumpkin Plant Wilting or Drooping
A pumpkin plant that seems to be wilting or drooping is likely being under-watered. High temperatures can cause your plant to use up its normally-satisfying water supply in a much shorter amount of time.
The best tactic for watering a pumpkin patch is to thoroughly soak the plants and the roots once a week in the morning. By watering in the early hours, you ensure that the water evaporates off the plants’ surface throughout the day. Nighttime watering can leave the moisture sitting on the surface of the plants and promote bacterial growth overnight.
Pumpkin Leaves Drying Up
Your pumpkin’s leaves could be drying because the plant is receiving too much sun. While pumpkins are generally full-sun plants, they need enough water to survive the extreme temperatures. Too much sun can scorch plants, especially when they are young and thirsty.
Make sure you are watering your plants thoroughly, once or twice a week. As they mature and the weather cools, then once a week should be enough.
Pumpkin Plant Not Flowering
Are you eagerly visiting your pumpkin patch every morning to check for the first signs of buds, only to find green vines and nothing else? You’re likely running to the patch too soon. It takes pumpkins 6-8 weeks from the time they are planted to produce any blooms.
During these two months, pumpkin plants will establish a stable root and vine network for the incoming fruit. The pumpkins’ leaves must be lush enough to guard the tiny gourds against the scorching summer sun. Once this network has been stabilized, the plants may feel healthy enough to produce flowers.
Alternatively, you may be frequenting your garden at a time when the flowers are not open. The male flowers of the plant are produced first and only last a day. These flowers open up in the morning to help attract bees, but since there are no female flowers for the first two weeks after the males appear, the male flowers simply drop off. You might miss this process altogether, depending on what time of day you examine your pumpkins.
Pumpkin Plant Not Producing
Generally, a pumpkin plant that is not producing any fruit was not successfully pollinated. Either there are not enough bees around to aid in the pollination, or the female flowers were stunted due to intense heat.
In less common cases, pumpkin plants will not produce fruit due to an excess of nitrogen in the soil. Nitrogen is healthy for the plant in small doses, but it will stunt the growth when too much is present.
To compensate for the increase of nitrogen, you can try and add some phosphorus to the soil. Phosphorus is a key component in the plant’s ability to produce flowers, so you may accelerate the process by adding it. Burpee Organic Bone Meal Fertilizer is rich in phosphorus and calcium while providing a low nitrogen content.
Ants are usually beneficial to have in the garden. While a few types of ants eat pumpkins, most of them are there to feed off other soil things. These ventures into the dirt help to aerate the earth, which provides better drainage for your plants.
There is one situation where having ants on your pumpkins should be taken seriously. Ants have a symbiotic relationship with aphids, which are sap-sucking insects that feed heavily on plants. These aphids can decimate your crop, and the ants will help them to do it. Ants protect aphids, so they can feed on the sweet substance the aphids produce while the aphids feed on your plants.
You can easily eradicate the ants by blasting your pumpkins with the hose. Ensure that you rinse off the underside of the leaves as well. If the aphids continue to return, visit your local garden store and pick up a colony of ladybugs. They will feed on the aphids, and help defend your garden, naturally.
Pumpkin Leaves Burning
Pumpkin plants love the sun though it is possible that extreme heat can cause the leaves to burn. However, it is more likely that your plant suffers from a chemical burn than a simple sunburn.
To treat pests and mildew, you may spray your plants with a chemical. A water and sulfur mix is a common defense against powdery mildew, but this mixture burns your plant, causing its leaves to curl back and die.
Try electing for organic treatments whenever possible; this will minimize the destruction of your pumpkins from chemicals.
Pumpkin Leaves Holes
Leaves with holes in them are usually a signifier of an attack on your plants. Several bugs could perform this attack, but bacterial infections are often the culprit as well.
To determine what is attacking your plants, you may have to make a few midnight trips to the garden. Many common pests are more active at night, feeding freely on the leaves when their predators are asleep. Take a flashlight with you and examine the tops and bottoms of the pumpkin’s leaves. If insects are to blame, you will likely find them feeding there.
Some of the top leaf-eating bugs are:
- Flea beetles
- Cucumber Beetles
- Squash-vine Borers
- Cabbage White Caterpillars
No matter the type of insect attacking your pumpkin’s leaves, you should defend your garden. The leaves provide the pumpkins with shade and feed the plant through photosynthesis. If bugs kill the leaves, they kill the pumpkins.
Safer Diatomaceous Earth is an effective way to kill bugs in your garden. This natural product is made up of extremely fine-grind silica or tiny glass particles. The earth grains are so small that the product is harmless to humans– some people even eat it– but when the pests come in contact with the silica, it is effectively damaging.
Be careful not to use diatomaceous earth if you will also buy ladybugs to hunt the aphids. The earth is deadly for the ladybugs as well.
Pumpkin Seedlings Leggy
Early on in their growth, pumpkin plants will be stretching out, reaching for the light. However, your plants should be creating strong vines from which a large pumpkin can safely grow. If your seedlings are very thin and leggy, they are likely not receiving enough sun.
Pumpkins are a full-sun plant. They defend themselves from the heat by creating a canopy of lush leaves. If you have placed your pumpkins in the shade, then the seedlings will become scraggly and leggy, reaching for the light.
It is near impossible to save your crop at this point. The plants are too young to be relocated, and supplementing their growth with a plant light is not realistic. You can hang a white sheet near the pumpkin patch to bounce more sunlight onto the growing leaves, though there is no guarantee this will make up for the lack of sun.
Pumpkin Frost Tolerance
Pumpkins are quite frost tolerant. While an early frost could kill a young pumpkin, mature pumpkins can sit happily in frosty temperatures as low as 28ºF (-2ºC). With that being said, the vines of the pumpkin plants are not very frost tolerant. The leaves and vines will die off in the cold, but the mature pumpkins will live on without them for a few weeks.
To extend the vines’ life, you can cover your pumpkin patch nightly as the temperature starts to drop. The pumpkins will stay warmer, and the frost will settle on the plastic sheet instead of on the pumpkins.
Pumpkins are a hardy fruit that loves sunshine. They can grow in full-sun areas, but if temperatures exceed 85ºF (29.5ºC), the plants can suffer greatly. They are also prone to drought in extreme heat and need a lot of space to grow.
Many bugs enjoy frequenting pumpkin patches as there is no shortage of greenery to eat, and these pests can also be detrimental to your garden. You can defend your plants against these ailments by spreading diatomaceous earth on the soil and watering your plants thoroughly once a week.
From a botanical point of view, the pumpkin is a fruit; however, it is considered a vegetable for culinary purposes. This dual description probably makes it hard to identify which problems pumpkins are susceptible to, right?
If you are having problems growing pumpkins, it has more to do with the inadequate space for growth, incorrect temperature levels, and poor watering practices rather than the right categorization of the plant. Also, pests and disease pose a significant challenge for the healthy growth of pumpkins.
Pumpkins are annual plants, so you have a short period to identify the problem and rectify it. Otherwise, you will end up with no harvest at the end of the growth cycle. This article offers a detailed look at the above problems and what you can do to fix them.
Space Restrictions That Curtail the Sprawling Vines
The pumpkin is a sprawling type of plant. This means that their vines need plenty of space to spread and grow. The vines are considered the umbilical cord of the plants because they sustain food and nutrient flow to all parts of the pumpkin.
Pumpkin vines of giant pumpkin varieties need at least 50 to 100 square feet per plant to produce an optimal yield. That typically applies to pumpkins like the Big Max and Atlantic Giant, which can produce pumpkins weighing hundreds of pounds at harvest.
Mid-sized pumpkins like the Jack-O-Lantern and the Autumn Gold need to be planted about four feet apart to accommodate their vines. The miniature varieties like Baby Boo require just two feet between plants because they do not spread too much.
Because pumpkins are sprawling plants, the question arises: Is it possible to plant them in a bag or container? The small variety of pumpkins can be grown in a box, but it must be placed outside. Since there may be a little sprawling, it is best to choose a pot of about 10 gallons in size for the smallest pumpkins variety. Plant only 2 to 3 seeds in one container.
An alternative for people who prefer to contain their pumpkins is growing them in a raised bed near a fence and training the vines to grow on a trellis or the fencing. This can work with small and medium pumpkin varieties.
Of course, with time, you will need to drastically prune the longer vines to ensure the plant remains healthy and productive. However, although the vines are prolific growers, they are also very delicate. So, take extra caution in handling them to avoid damaging the remaining vines.
Shallow Watering That Results in Stressed Pumpkins
Pumpkins are thirsty plants that require a lot of water to remain healthy and productive. Ensure that you water your pumpkin patch deeply at least once a week and maintain one inch of water in the ground throughout the week. That means that the plant has about 16 gallons of water in the soil in the week. During the fruit set, you may need to water it a little more.
However, it is essential to make sure that the fruit and leaves do not get saturated with water. Too much water on these parts makes them susceptible to rotting and other fungal diseases.
As your pumpkins grow, you need to apply mulch to them to keep the soil moist at all times. Mulch also suppresses the growth of weeds, which compete with the plants for nutrients. It is best to control weeds around pumpkins by mulching rather than using a hoe to remove them. That is because pumpkin plants have shallow roots that you can easily damage when trying to remove the weeds by hoeing.
Slow irrigation works best for pumpkins because it ensures that the soil doesn’t dry out at any one time. Place the sprinkles next to the base of the plant so that the water goes directly to the roots. This approach prevents the leaves and fruit from getting wet.
Nutrient Deficiency Causing Poor Yields
Pumpkins are also very heavy feeders. The best way to tell if they have any nutrient deficiencies is by testing the soil before planting. You can either send the soil to experts or carry out a home test using a testing kit bought from a gardening store.
Pumpkins do well in slightly acidic soil, so it should have a PH of 6.5 to 7. The plants are unable to thrive in soils below this PH because of the high levels of acidity. Highly acidic soils prevent the pumpkins from absorbing nutrients from the ground efficiently.
On the flip side, soils above a PH of 7 are too alkaline, allowing the pumpkin plant to take in too much of the nutrients available. As a result, the plant is unable to process the excess nutrient, leading to the pumpkin dying.
Manganese and Magnesium Deficiency
Manganese and magnesium deficiency are both characterized by discoloration, and the pumpkin leaves falling off. Before they fall off, you will notice the pumpkin plant wilting.
Magnesium and manganese deficiency is rectifiable by keeping the PH of the soil at the 6.5 and 7 levels. You can rectify the soil PH by adding water-soluble lime or Epsom salts depending on the acidity of the soil.
Nitrogen deficiency results in the pumpkin plant turning yellow and rapidly dying off. Potassium deficiency is aptly named “hidden hunger” because the plant rarely shows signs. However, when it is severe, it looks as if the pumpkin leaves are burnt due to the scorched leaf tips.
Before planting, make sure that you use aged organic compost in the soil. Most of the above-mentioned nutrients can be added naturally into the soil using organic compost.
However, after the PH test is done, you can also add some fertilizer to the soil. Experts recommend making sure the plant receives the right nutrients from the fertilizers.
For example, use magnesium and heavy manganese fertilizers in deficient soils and make sure that you apply nitrogen fertilizer on the plants. Nitrogen from the compost may be tied up in the organic matter, becoming unavailable to the plant. The fertilizer releases nitrates, which are easily absorbed by the pumpkins. Nitrogen is crucial for healthy plants and promotes rapid growth.
Pumpkin gardeners may find that applying different fertilizers at the various developmental stages of the plant is a winning formula for a bumper harvest. Using a nitrogen-heavy fertilizer in the early stages of growth promotes good health in the plant.
A phosphorous-heavy fertilizer when the plants begin to flower causes the pumpkin to produce a lot of blossoms. The more the flowers, the more the chances of pollination and the higher the number of fruits produced. When the pumpkin fruits sprout, utilize a potassium-rich fertilizer to make the fruits healthy.
Frost Damage Due to Cold Temperatures
Pumpkins are warm-weather plants meaning they thrive best in warmer temperatures. These plants are extremely sensitive to frost. You need to start your pumpkin seeds indoors about three weeks before the last frost on the ground. The timing gets them ready for immediate transplanting at the beginning of the warm weather, increasing their exposure to warm conditions.
The ideal indoor temperature for the seedling to germinate is 70°F (21°C). Since the top coat of the seedling can be hard, try and soak the seeds in warm water an hour before planting to weaken the coat and speed germination. You can achieve a warm temperature indoors by using fluorescent lights and keeping the soil moist.
If you are directly sowing the seeds into the ground, ensure that the last frost is completely gone, and the soil temperature has risen to about 65 to 70°F (18 to 21°C). For gardeners in cool summer regions, it is recommended to grow quick maturing pumpkin varieties. Those in areas with scorching summers should plant their crops in late winter for the temperatures to be agreeable.
Pumpkin frost tolerance is limited to a light frost, which will not damage your pumpkin. It is advisable to harvest the pumpkins before the temperatures fall to the mid and low 20°s.
If your pumpkins are exposed to temperatures below 27°F (-3°C), the cold injury could be severe. Such frost damage kills the vines cutting off the food to the fruit. In this case, you have to harvest the salvageable fruit and place it in a sunny patch to cure. If they are too green to ripen, use them for decorative purposes.
Also, harvesting when the temperatures are still warm ensures that the pumpkins can be cured effectively. Pumpkins need temperatures of between 80 and 85°F (27 and 29°C) for curing to harden their skin and close up any cuts.
Delayed Pollination Resulting in No Fruit
It is quite common for a pumpkin not to produce fruit. The direct consequence of missed pollination is a pumpkin plant not flowering. You can tell your plant is not pollinated when the vines are healthy, but the plant is completely devoid of fruit.
The pumpkin plant relies on bees for pollination. Pumpkins produce male and female flowers, with the males appearing first to attract the bees. The female flowers appear at least two weeks after the males have appeared. Female pumpkin flowers only open for six hours per day, so pollination will not take place if bees miss their opportunity.
If the weather is not favorable, the female flowers may delay coming in. As a result, the plant misses its pollination period, or if pollination takes place, the fruit set produced is too weak and develops poorly before the colder seasons set.
Too much nitrogen in the soil can also cause the growth of the male pumpkin vines, but no flowers come from an otherwise lush plant. Additional causes for a pumpkin plant not producing fruit include drought stress and waterlogged soils.
Some gardeners prefer to take matters into their hands by hand, pollinating the flowers. Hand pollination should be done before 10 am every morning on the day the female flower opens up. You have to monitor the female flowers for a few days to get them on the right day. Use a soft brush, cotton swab, or even your finger to transfer the pollen from the male to the female.
Pest and Diseases Afflicting the Plants
At first sight, the squash bug can be confused for a stink bug. Both bugs have the same oval abdomen and square-shaped thorax with a flat back. They both also produce a terrible odor when crushed. Unfortunately, the squash bug is an even bigger menace because they are hard to get rid of and cause a lot of damage in a short period.
They have piercing mouthparts that allow them to make holes in the foliage of your pumpkin plants. Within six to eight weeks, the squash bug has hatched from an egg and matured into an adult. In the 120 days it takes for your pumpkin to produce fruit, these pests will have eaten through the leaves and flowers, resulting in an inferior yield.
As their name suggests, these pests target the vines of a pumpkin plant and suck the moisture from them. The larvae are the main culprits. As soon as they hatch from the eggs, they proceed to bore into the nearest pumpkin vine. They may escape notice because they spend most of their time within the vine, eating it from within.
However, you should inspect your plants for green or yellow frass that the larvae leave on the stems of the plant, especially near the feeding site. Unfortunately, there is no way to salvage a wilting pumpkin vine that has been infested by vine borers.
Management of vine borers needs to be a preventative effort to eliminate their chances of infesting the crop at all. Since they infest the crop in July and August when their life cycles begin, treat the plant with insecticide right before this period, around mid-June. Follow up treatments must also be scheduled for every five to seven after the initial treatment.
Apply the insecticide at the base of the vines because this is the area most susceptible to vine borers. Also, consider covering the vines with Kaolin clay. Finally, try planting vine borer resistant varieties like the Dickenson, Connecticut Field, or Small Sugar pumpkins.
Anthracnose is a fungal disease that spreads quickly in pumpkins because it thrives in warm environments. Earlier, this article mentioned that when watering your pumpkins, avoid getting water on the foliage and fruit. This disease is the primary reason why it is crucial to keep these parts dry.
It manifests as sunken black spots on the fruit, pumpkin rot on the vine, and brown spots on the leaves. Anthracnose is caused by spores spreading from infected plants through water and even your hands and equipment. This disease appears after the pumpkin has formed a healthy canopy of leaves. Sometimes you may notice the pumpkin leaves with holes because the disease causes patches of the leaves to drop out.
Anthracnose can result in complete defoliation of the pumpkin plant, especially since it begins attacking the older leaves before finding its way to younger leaves.
One of the primary ways to prevent this disease is by purchasing clean seeds for every planting season. Saved seeds may have the anthracnose spores resulting in an infected crop.
Gardeners should also avoid working in their pumpkin patch while it is wet.
Destroy any infected pumpkins at the end of each season and use fungicides against the disease. Consider crop rotation without planting any crops in the pumpkin family for at least three years.
Another fungal disease that commonly afflicts the pumpkin plant is the powdery mildew. It appears as powdery white fuzz on the leaves and vines of the plant. Powdery mildew thrives on pumpkin plants because they grow in warm weather with plenty of water around.
The pathogen that causes this disease can be carried by wind to the pumpkin patch. However, it can quickly become a problem when it finds three consecutive days of hot and dry days with warm, humid nights.
The white fuzz quickly covers the vines and the lower part of the leaves on the pumpkin. It targets these parts first because they are away from the sun. Soon enough, however, the fuzz spreads throughout the leaves, covering the top part as well.
Classic symptoms of mildew are yellowing of the leaves, followed by the pumpkin plant drooping and dying. This disease can quickly be taken care of using fungicides. You can also opt to plant pumpkin varieties that are resistant to powdery mildew.
It is not hard to care for a pumpkin plant. They are healthy and thriving as long as you remember that:
- Pumpkins love warm weather.
- They need plenty of water despite loving warm temperatures.
- The vines need to be controlled periodically to maintain a healthy plant.
- They need to be pollinated so make the garden a bee-friendly zone.
- They don’t do well in a competing environment, therefore, clear nearby weeds.
All types of pumpkins take the same amount of time to grow from seed to fruit. And they all need the above conditions to thrive.
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