Are Your Squash Plants Dropping Flowers and Fruits?
Squash is one of the most productive plants in the vegetable garden; not only are they highly productive, but they also produce very early on in the season and the fruits grow rapidly.
Most of the time. When conditions aren't ideal, squash can be hesitant to flower and fruit successfully. Sometimes, the causes aren't as obvious, making it more difficult to diagnose the problem. Since squash plants require that female blooms are pollinated by male blooms, problems with fertilization are more likely to occur than they are with self-pollinating vegetables, such as tomatoes.
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| Female blossom recently pollinated on a Tennessee Spinning Gourd, also known as a Tennessee Dancing Gourd. |
If your squash plants are blooming like crazy but you're not seeing any fruits forming, be sure that the flowers aren't male. The male flowers are easy to tell apart from the female flowers; female flowers have a tiny little squash at their base, which is very easy to see. Male flowers will have a long, thin stem attaching them to the main vine.
When squash plants are young, they tend to put out a flush of male flowers. After a while, a female flower is produced. This might be a survival technique among squash plants; having several male flowers in bloom ahead of a female flower ensures that there is pollen available (and plenty of pollinators buzzing around) for the female when it blooms, increasing the chances of successful reproduction.
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| Look at the stem attached to this young bud; it is straight and smooth, with no young fruit. This is what a male squash blossom looks like. |
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| There are many different types of flying pollinators that visit squash flowers- and even some that don't fly, such as ants or beetles. |
Issues with Pollination & Accessibility for Pollinators
If you're seeing flowers but no fruit, one possible cause is a lack of pollination. Squash plants absolutely require that their female flowers be pollinated by insects or by hand. If you are growing your squash under a row cover to prevent insect damage, you will need to hand pollinate your flowers or uncover them so that insects can do the job. I've also heard about blue bottle flies being used for pollination for flowers, so this might be an option. (I am considering doing an experiment with blue bottle flies to see if it works.)
If your squash is uncovered and you're still having issues with pollination, take a look at the insect population in your garden. If you don't see you very many bees or flies, that's possibly the problem. Before you consider this though, ensure that you do have female flowers blooming, that your daytime temperatures are ideal, and that the plant is not suffering from a lack of sunlight or nutrients. Pollinators do their work very quickly, and they tend to be quite efficient. It doesn't take very many bugs to pollinate your garden. You do require a little diversity; however, this isn't usually an issue in most gardens. Even though bees and butterflies are what most people consider pollinators, there are many other different types of bugs pollinate as well. Flies, hoverflies, small mammals, beetles, and many other bugs are potential pollinators in the home garden.
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| What appears to be a squash bee pollinating a squash flower. Did you know that there are bee species that specifically pollinate squash? |
Blossom and Fruit Drop Due to Heat Stress, Environmental Stress
Like many other vegetable plants, stressful environments can cause blossom drop. One of the most common reasons for squash blossom drop is heat. Heat waves affect most of us during the summer months, and squash can become quite fussy once the temperatures begin hitting the upper 90s. If your temperatures have been rising, you might consider this as a cause.
If you're having bright sunny days and high temperatures, one solution that most people use is shade cloth. Shade cloth can help to lower the temperature by a few degrees by providing some shade to the plants. This also reduces the sunlight that the plants receive, providing some relief. The midday summer sun is relentless and unforgiving, sometimes it's simply too much for our plants to handle.
Sometimes water stress can be tied in with this. Be sure the soil is kept moist especially whenever the temperatures begin rising.
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| Female squash blossom blooming with young fruit attached. |
Lack of Sunlight, Competition for Light
When plants don't receive enough sunlight, their productivity usually takes a hit. If your squash is planted on the northern side of a structure, or if your yard is shaded, this might be the reason you're not getting many flowers or fruit. I recently discussed the issues surrounding planting to the north. Try to remove any possible obstructions to increase the sunlight that the plant receives. If possible, move squash that's planted in containers to a location with a clear view of the southern sky.
Weeds can also cause a lack of sunlight as they overtake the plant. Even other veggie plants in your garden can cause this problem; If your plant spacing is too tight, you're not giving each plant enough room to spread out and photosynthesize as they should. If your squash plants are tightly spaced, try using a trellis to give the vines somewhere to go. This DIY trellis I made was cheap and made of natural materials. Be sure that each plant has adequate spacing, and that the weeds are taken care of if this is the potential cause.
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| Happy little pollinator visiting a gourd blossom. |
Soil, Location, and Fertility
If your plants are yellowed, small, or don't seem to be growing to a large size, you may have an issue with your soil, location, or fertility.
Small, yellowed plants can indicate overwatering and waterlogging. If overwatering is the issue, allow the plant to dry out. Stick your finger an inch into the soil when you plan to water; If the soil feels moist, do not water. If your squash plant lives in a low spot on your property, see if the soil seems soggy. If water tends to pond there after a rainstorm, you may need to relocate the plant to higher ground. If your rainy season is short-lived, you could leave the plant in place, and it will recover when the weather dries out- as long as root rot or other diseases don't set it.
Small, yellowed plants can also mean there's poor fertility, such as a nitrogen deficiency. If waterlogging isn't an issue, look at your soil quality and scan neighboring plants for similar symptoms. If you used a cheaper soil type, such as topsoil, those tend to be blended forest products with lots of mulch and sand; they tend to be low in nutrients. A balanced fertilizer could help the plant to begin growing as it should if this is the case, allowing it to flower and fruit successfully.
If the plant is small, but isn't yellowed, it's possible that its roots could be facing problems, or there might be something inhibiting growth. If you're growing squash in a container, there may not be enough space for its roots, resulting in a smaller plant. Sometimes, pests and disease can strike beneath the soil's surface, making it difficult to notice that something is wrong aside from slow growth. Vine borers (see my video for treating vine borers by injecting BT into the squash vines) are one pest that's difficult to notice until it's too late; but they don't typically affect the growth rate of young seedlings. Lastly, there are plants that are allelopathic. These plants can prevent neighboring plants from growing, effectively reducing competition for resources and nutrients. If you happened to plant your squash beneath a walnut tree or another allelopathic species, you may encounter very poor growth and production.
I believe this was a Tatume Squash, but I may be wrong.
Giving Squash What They Need
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| I believe this was a Tatume Squash, but I may be wrong. |
For the best performance, try to give your squash an environment that they can thrive in. I know that's easier said than done, but here are the conditions that squash plants love:
- Squash plants prefer consistently moist soil, but not wet feet. Avoid low spots.
- Squash plants require full sun, but the midday sun can be overly harsh; plants may wilt down in high temperatures with lower humidity. Shade cloth can help.
- Fruit production will be lower when days approach the upper 90s, you may need to adjust your planting dates for future gardens, and you may need to utilize shade cloth.
- They require pollination by insects or by hand in a netted environment, this is key for fruit production.
- A balanced fertilizer is a good start for squash plants. A fertilizer with a slightly lower nitrogen value is a better option, but squash plants tend to put that nitrogen to use.
- Squash requires lots of space to grow and vine. It's a very competitive plant, but it can be outcompeted by other vines, perennial grasses, or even other squash plants.
Hopefully, with these tips, you'll harvest more squash than you know what to do with! Squash is incredibly prolific, and one of my favorite ways to store it is to dehydrate it. It's easy to slice, dehydrates evenly, and stores very well in the pantry as a shelf stable food. I do enjoy freezing it, but freezer space isn't as easy to come across as pantry or shelf space is.
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| Dehydrated zucchini and yellow crook neck squash. |