Zucchini is a summer squash that can sneak up you. Large, prickly (edible) leaves shade the ground and defend against insects. They also hide the occasional zucchini, allowing it to reach horse leg proportions. In Britain, they call these epic squash ‘marrows’, but zucchini are generally harvested when much smaller and younger. According to Guinness World Records, the longest zucchini on record was over 8 feet long and the heaviest weighed in at over 64 pounds! Holy smokes! Imagine stuffing one of those monsters!
Before our zucchini ever reach those proportions, let’s learn more about how they grow and how we can help them be flavorful and productive.
How zucchini plants grow
Zucchini are members of the Cucurbit family, making them cousin to pumpkins and melons. Botanically, zucchini are berries - isn’t science fun? Adding zucchini to the garden or landscape is an excellent way to grow your own food. Like other gourds, zucchini have both male and female flowers. Both flowers are edible, with the pistil and stamen removed. Zucchini flowers can be deep fried, baked, sautéed, or added to soups or salads. Personally, I’d rather have the more substantial produce, so I leave the flowers alone. Honey bees and other pollinators are needed, so avoid using broad-spectrum pesticides near zucchini plants. If there are not enough pollinators, you can always hand-pollinate.
Zucchini is a very forgiving and productive plant and it loves our California weather. You can grow zucchini in large containers, straw bales, towers, raised beds, or in the ground. Seeds germinate best at 70° to 95°F and should be planted one inch deep. You can plant seeds individually or in hills. Individual plants should be spaced 3 feet apart. Hills (6-8” high and 12-24” wide) can support two or three plants. Zucchini plants do not handle being transplanted very well and they will benefit from a layer of mulch. Be sure to irrigate regularly. Water-stressed zucchini, and other squash, will taste bitter. This bitterness is caused by toxins that can be potentially dangerous. Don’t let this scare you off, just be sure to water your zucchini plants regularly. This will also help prevent blossom end rot.
Zucchini pests and diseases
Sporadic watering and insufficient calcium can cause blossom end rot in zucchini. Overhead watering can cause powdery mildew, downy mildews, and white mold, so irrigate regularly with soaker hoses. Other diseases include curly top, damping-off, fusarium crown and foot rot, verticillium wilt, and various viruses. Aphids (isn’t it always aphids?), earwigs, cutworms, cucumber beetles, crickets and grasshoppers, slugs and snails, flea beetles, armyworms, nematodes, loopers, leafminers, leafhoppers, thrips, squash bugs, squash vine borers, spider mites, wireworms, and whiteflies will all want some of your zucchini. The good news: you’ll still probably end up with more zucchini than you know what to do with!
Too much zucchini?
Zucchini plants are very productive. While harvested zucchini are very mild and can be adapted to many different dishes, sometimes you just need a change. After you have sautéed, stir-fried, baked, grilled, and broiled all the zucchini you can handle, try my family’s recipe for Chocolate Zucchini Cake. This particular recipe has been responsible for transforming the opinions of toddlers, teens, and skeptics for generations. Zucchini can also be pickled, and you can puree it and freeze it for later use. Don’t bother trying to freeze cubed zucchini - it doesn’t end well.
Zucchini and the cross-pollination rumor
Many gardeners worry about cross-pollination between members of the gourd family, but this worry is unnecessary. Natural cross-pollination can only occur within a species (we will not discuss genetic manipulation at the nano surgery level). This means that zucchini plants can cross-pollinate with other zucchini and summer squash varieties, but not with melons or cucumbers. This is actually how we get many new cultivars. When cross-pollination does occur, it has no affect on the current season’s fruit or vegetable. It does alter the DNA within next year’s seeds.
Even if you are a card-carrying Brown Thumb, give zucchini a try this year. It is a very rewarding plant and you can never have too much Chocolate Zucchini Cake!
Cucurbits refer to the gourd family and it includes squash, pumpkin, zucchini, melons and even luffas! Most of the 975 species are susceptible to frost and many are trailing annual vines.
Watering early in the morning allows the leaves to dry out before evening, helping to prevent powdery mildew and other fungal diseases. Because of the wide leaf coverage of most cucurbits, weeds are seldom a problem. Cucurbits are frequently attacked by squash vine borers and squash bugs, so squash those bugs whenever you see them!
Be sure to harvest fruits regularly, to ensure continuous production. Once plants believe they have completed their reproductive cycle, you generally won't get any more fruit.
I hope this information inspires you to grow more of your own food. You can ask your garden questions on my Home page.