Fertilizers, Pests and Harvesting Techniques for Squash

Once squash starts to emerge, maximize the output of your plants -- and protect them from predators -- with these easy tips.
squash bugs can do major damage to healthy plants

squash bugs can do major damage to healthy plants

The squash bug: this intruder can do major damage to healthy plants. Keep a watchful eye out for these pests and eliminate them early to prevent serious harm.

The squash bug: this intruder can do major damage to healthy plants. Keep a watchful eye out for these pests and eliminate them early to prevent serious harm.

Once the squash have come up, you'll need to cut out the weakest ones to leave room for the strongest to continue growing. By leaving only the strongest, you'll get more yield, or bigger harvest from the remaining plants. This is a good way to encourage natural selection, especially if you plan on taking cuttings or using seeds from your garden.

To get a continuous harvest of your favorite vegetable, it may be necessary to plant it several times during the growing season. This is called successive planting. For squash the harvest duration is about 1 and a half months so it should be planted several times to get an endless summer supply. Another reason gardeners like successive planting is so they can reserve part of the harvest for later use. Summer squash can be easily frozen or canned for use in colder months. A few squash plants can produce enough to feed an entire family, add a few more and you've got food for the whole year.


Squash need a lot of fertilizer. When you planted your seeds you put a small amount of 10-10-10 around the planting locations. Now that the plants are coming up, they need another small dose. Do this by sprinkling the granules on the ground around the base of the plants. Read the package to see how much to use for each plant. This will provide the nutrients needed for the fast growth the squash will have over the next few weeks. Water in the fertilizer well so that the plant roots won't burn. Too much fertilizer will do more damage to a plant than no or not enough fertilizer, so be sure to read the directions on the package or ask a professional at your local garden center. Remember to always wear a mask and gloves when using fertilizer.

Controlling Pests

One of the best things a gardener can see in the garden is a bee. Bees are responsible for pollinating the flowers on your vegetable plants. Without pollination, a vegetable plant will never produce fruit. These yellow and black visitors are so important that many farms raise their own bees to get adequate pollination. If you see bees in your garden, don’t harm them. They're doing a very important job for you.

There's another yellow and black guest that no gardener ever wants to see, the cucumber beetle. They attack young plants and fruit. A few cucumber beetles can wipe out your squash beds. The best way to get rid of these beetles is to pick them off with your hands, but make sure you have on gloves. Another unwanted pest is the squash bug. It attaches itself to a stem and sucks out the juice, leaving the plant yellow and wilted.

Squash bugs are tan to black and look like a small armored battleship. Both of these pests can be controlled with pesticides, but garlic spray and insecticidal soap are better first steps since they're less toxic. Whatever pest control you buy, make sure you carefully follow the instructions on the package. And, as with fertilizers, wear gloves, mask and goggles when using pesticides.

Squash vine borers are small larvae that drill into the base of the plant stem and eat the inside, keeping the plant from getting water and nutrients into the leaves and fruit. There are several types of organic treatments such as beneficial nematodes and garlic spray. One of the most popular ways to prevent vine borers from attacking young plants is to wrap the stems with tin foil. This keeps the borers from getting to the plant by creating a barrier they can't cross.

Squash are also prone to a variety of diseases like cucumber mosaic virus, powdery mildew, downy mildew and root nematode disease. The best way to protect your garden from disease is to make sure that your rows are not overcrowded and pick off any diseased fruit or limbs and discard them immediately. One way to make squash more resistant to mildews is to water in the morning, not at night. This gives the leaves a chance to dry out before dark, the time when mildew grows best. Since these diseases are fungi, you may need to use a fungicide, a chemical that destroys fungus, to cure extreme cases of mildew.


The secret to harvesting any type of summer squash is harvest early and harvest often. Once a squash plant begins to produce check it every day for harvestable fruit. Yellow squash and zucchini are harvested when they're 4-8 inches long; any longer and they begin to get bitter. Patty pan squash can be harvested when they're very small. The smaller the patty pan the more flavor it has, any larger than 4 inches and they begin to lose their great taste. Overripe or large fruit can actually slow down a squash plant's production because it tells the plant that it doesn't need to start any new fruit.

The best way to harvest squash is by using a clean knife and using your arm to go directly into the plant where the fruit is sprouting. Since squash have small spikes, you might get scratched up if you try to reach across the entire plant. Once you grasp the fruit use your knife to cut the stem. Push the blade away from your hand so that you won't cut yourself. A knife makes a clean cut that heals over more quickly than a break. Pests can attack your plants at breaks so be sure and make the cut as smooth and clean as possible.

Check on the zucchetta rampicante you planted on the trellis. Its fruit will be very long and slender; this variety is harvested when it's bigger than most zucchini.

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