14 May 2015, written by Ann Marie Hendry
One of the simplest vegetables for beginning gardeners to grow from seed is the zucchini, which is easy to care for, quick to grow, consistently prolific, and endlessly useful in the kitchen.
Although growing zucchini isn’t difficult, it took me some time to get a really good crop, so it’s worth taking the time to make sure the conditions are right. Here are my tips to ensure a steady supply of zucchini because, believe me, it can be annoying if every gardener you know is complaining about their glut when you’ve only managed to produce a few fruits late in the summer.
To reduce the chance of them going bad, plant zucchini seeds on their side so that water can drain off easily. Keep seedlings in a sunny location indoors until all risk of frost has passed after they have germinated (which typically takes about a week, give or take a day or two), then harden them off to acclimate them to outdoor conditions. If the weather is warm enough, you can also plant them outside under cloches or horticultural fleece (row covers). Don’t start growing zucchini too early because they can’t tolerate cold temperatures. Instead, use our Garden Planner to find the best times to sow and plant out your garden.
Zucchini require a lot of fuel in the form of nutrients from the soil and sunlight to help them photosynthesize effectively if they are to be highly productive. It is best to plant them in well-rotted manure or garden compost-enriched soil in a sunny area of the garden where they won’t be shaded by other plants.
Although many people successfully grow zucchini in containers (especially compact varieties), I personally never seem to get as good of a crop. It is important to stay on top of watering and feeding when growing in pots, but I must admit that I occasionally neglect my houseplants.
Keep cloches or fleece at the ready for cool nights. If the soil is dry, water the area frequently, and add mulch to reduce weed competition and help the soil retain moisture.
Your zucchini plants will initially only produce male flowers when flowering begins. My hypothesis is that male flowers are produced because they attract insects like bees who will return to the plants once the female flowers are produced, improving successful pollination.
Some of these male flowers can be consumed by deep-frying them, but be sure to leave enough on the plant for successful pollination. Female flowers have an immature zucchini fruit behind them, whereas male flowers are produced on long, thin stalks with no such swelling, so you’ll know when your plants have started to produce them.
As soon as flowering starts, begin fertilizing your plants with a liquid tomato feed or a home-made comfrey fertilizer twice a month. Continue to keep the soil well-watered.
One issue that is of significant concern is poor pollination. For successful pollination of zucchini, many bees or other pollinators must visit; otherwise, the fruits will not develop. The fruits will then stop growing, turn yellow, and possibly begin to rot. To prevent this, make sure your vegetable garden has a lot of pollinator-friendly flowers, and refrain from using any pesticides. You can also manually pollinate the flowers, which may be necessary during rainy summers when insect pollination is insufficient.
Make sure to keep plants well-watered and cover them with fleece or something similar if the weather turns cold because stressed plants may also abort their fruits.
In addition to zucchini, cucumber mosaic virus (CMV) also affects cucumbers, squash, pumpkins, and some other unrelated plants. CMV-affected zucchini will have mottled, puckered leaves and distorted, bitter-tasting fruits. By cultivating a lot of nectar-producing flowers that will draw aphid predators like lacewings, lady bugs, and hoverflies, you can control aphid populations and prevent the spread of disease. A strong water jet can also be used to spray aphids off of plants whenever you see them.
In hot, dry weather, powdery mildew can also affect zucchini, but fortunately it is easily avoided by spraying diluted milk.
An abundance of vegetables is not a bad problem to have, but there are limits… The zucchini glut is well known not only to vegetable gardeners but to their families, friends, neighbors, and casual acquaintances as well.
The key to preventing a glut of zucchini is to regularly pick the fruits when they are still small, up to about 20 cm (8 in). Additionally, eating some of the male flowers will aid in reducing output.
Even so, because they are so versatile, zucchini are likely to be a constant in your diet. They can also be grilled, fried, baked, stuffed, grated into sauces as a thickener, sliced thinly into salads, or made into fritters or zucchini bread. I like them best when they are roasted with other vegetables and added to pasta, but they can also be prepared in other ways. Contrary to what some chefs claim, you can freeze zucchini. However, because they become a bit mushy when frozen, they are best used in dishes where the texture isn’t as important, like zucchini soup.
If you have any advice for growing a fantastic crop of zucchini or for getting rid of an excess, please share it in the comments section below.
Leaves or Fruits Are Mottled or Distorted
Do your zucchini plant’s leaves look kind of funny?
They might be distorted or unusually small. Or maybe they have serrated edges or dark green blisters.
Any fruits that eventually develop will also be stunted and malformed.
Bad news. It’s likely zucchini yellow mosaic virus (ZYMV).
Mosaic virus can be contracted in several ways:
Unfortunately, once the mosaic virus has infected your plants, there is nothing you can do. Pull up the plant and destroy it. Don’t add it to your compost. Wash your tools well, and try again next year.
Make sure to tidy up your garden bed at the end of the year because the virus can overwinter in weeds in the soil. If you want to be safe, you might think about planting somewhere else.
There is one potential solution, however. If you live in a warm climate and this disease strikes early in the growing season, you might still be able to plant another crop in time for a harvest.
Always remember to clean your shovels, rakes, and clippers after each use in the future. Plant resistant zucchini cultivars, and keep aphids at bay.
What Causes Zucchini Fruit to Fall Off the Plant?
Lack of or inadequate pollination is the most typical cause of zucchini fruit falling off the plant. This indicates that your zucchini plant’s flowers were not properly pollinated for some reason, preventing the fruit from setting seeds. Remember, a plant’s sole purpose is to produce seeds. The plant will “abort” the fruit when it has demonstrated it won’t set seeds rather than expend valuable time and resources on growing it.
Blossom end rot is a less frequent cause of zucchini fruit falling off a plant. The fruit’s stunted growth and blackened ends are the telltale signs of this.
Stress is another cause of premature fruit drop in zucchinis and other squashes. Plants receiving less than eight hours of sunlight daily often attempt to make fruit that fails to develop. Container-grown plants can experience moisture stress, and in an attempt to conserve water to survive, the plant will sacrifice its crop by dropping it. Overwatered plants can develop problems such as powdery mildew, a fungus that coats leaves in a pale gray dust that inhibits photosynthesis and causes general plant decline, says Texas A&M AgriLife Extension. Water zucchini directly at the base of the plant, and never from above, because wet foliage encourages the development of mold and mildew.
After a brief biology lesson, differentiating between male and female zucchini flowers is simple. Almost always, male flowers are the first to bloom, are produced in large quantities, and are held away from the plant by long, narrow stems. Female flowers arrive later in the growing season and are located closer together along the vine. The ovary, which swells after pollination to become the mature, edible fruit, can be seen behind the flower appearing to be a miniature version of the future vegetable. For successful pollination, both male and female flowers must be present; new flowers open every day and are only open for a few hours.
If an area’s honeybee population is lacking or the zucchini is growing on a balcony, patio or hardscape such as a driveway, there simply won’t be enough visitors to the plant to get a good crop of zucchini going. If lack of insects is a likely culprit, try hand-pollinating the zucchini flowers. Use any soft, small paintbrush to collect pollen from the interior of a male flower, and dust it thoroughly onto the parts of the female flower, instructs the University of Florida IFAS Extension. Make sure you coat the female flower thoroughly; incomplete pollination can result in aborted or misshapen fruit. Pollinate daily, and early – flowers and pollen are freshest in the morning and degrade quickly as the day advances.
Summertime gardeners have a running joke: If a neighbor is toting a bulky bag of produce, it’s probably squash that he can’t bear to part with. The most frequent criticism of zucchini (Cucurbita pepo) is that there is always too much of it. But as soon as those first baby squash appear in the garden, excitement increases before the zucchini outstays its welcome. Observing those developing babies wilt and drop from the plant can be depressing.
The zucchini plant is monoecious, bearing both male and female flowers on the same plant, like other squashes. The task of transporting the pollen from the male flower to the female flower, where the fruit begins to develop, is typically carried out by bees and other insect visitors to the flower. The baby squash does not grow when this process is unsuccessful, according to the University of California Cooperative Extension; instead, it turns yellow, shrivels, and falls off the vine.