Growing Zucchini and Summer Squash is easy.
It’s one of those great crops that you need to harvest every day or two, otherwise, they become huge. Over-sized ones are called marrows, and are still great for many zucchini and summer squash recipes. I often freeze shredded zucchini marrows once they’ve reached a large size.
Zucchini tend to be long and thin in shape. Summer squash belong to the same family, however they come in many fun shapes.
This post will cover
- Zucchini and summer squash types and varieties
- Growing zucchini and summer squash
- When to harvest
- Dealing with problems like blossom end rot or lack of yield
Beautiful Varieties of Summer Squash
In general the colors are yellow, dark green (your typical zucchini at the grocery store) and other shades of green. Shapes can be round, or ‘patty pan’ which is a scallopini shaped squash. Bennings Green Tint is a very light green, almost white color. You can also enjoy Romanesco/cocozelle types that are ribbed and striped.
Below is ‘Bennings Green Tint’
This summer I’m trying ‘Total Eclipse’ from West Coast Seeds
‘Ronde de Nice’ (cute for stuffed recipes)
‘White Marrow’ summer squash
Growing Zucchini & Summer Squash
This is a warm season crop with no tolerance to frosts. You’ll need to make sure that your planting after your spring frost. Start seeds indoors 2-3 weeks before your last spring frost dates. If you start them too early indoors, they can get root bound and stressed. The other option is buying a seedling from your local nursery. Seeds can be directly sown into the ground, but they’ll take much longer to grow and you’ll be about a month behind for harvesting. Optimal soil temperature: 25-35°C (68-95°F). Seeds should germinate in 7-14 days. I’ve found our indoor grown seedlings usually germinate in our indoor greenhouse with grow lights in a few days.
Transplant zucchini and summer squash after your spring frosts.
I make two plantings, one in mid May, and a second early June
Zucchini and summer squash enjoy loose soil amended with compost. A nice balance of NPK is important. If calcium is too low, then blossom end rot will happen. Ideal pH: 6.0-6.8 and they need decently rich soil, so add fertilizer or decomposed manure and compost. I love adding sea soil underneath our seedlings.
Zucchini plants can take up a lot of space, when garden planning be mindful of that.
As Zucchini and summer squash are a fruit, pollination is needed.
As they are a fruiting plant, meaning they grow from the flower. If the flower isn’t pollinate = no yield.
That means you need bees, or to hand pollinate, to have harvests.
To hand pollinate you need to take the male flower to the female flower. The female flower is the one with the fruit that’s begun to grow. Once the flower opens, the male flowers which are on a thin stem, need to be take to the female flower once it opens. If you notice you don’t have many pollinators around, this will be something you need to do. It’s one of the most common reasons why zucchini fruit doesn’t produce anything
Zucchini Rotting on the Plant?
You might have blossom end rot if your zucchini is rotting or lack of pollination.
I discuss this problem in detail and offer solutions in this zucchini rotting post. Powdery mildew can become a problem towards the end of summer. Try watering at the base of the plant and in the morning so there’s less moisture on the leaves. Make sure there’s decent air flow for plant spacing to reduce.
When to Harvest Zucchini and Summer Squash
They’re usually ready in 45-60 days depending on the variety. They will keep on producing (many many) for at least a month. Keep picking smaller ones otherwise they’ll stop. After about 1 month of continuous harvesting, they tend to dwindle which is why making two plantings can help spread out those harvests.
The flower will dry out on the end once it’s ready to harvest.
I tend to be pretty eager to harvest zucchini early summer and harvest a few with the flower still on them. You can actually eat the zucchini flowers, in fact, they’re a delicacy fried in Italy. The make flowers tend to be chose over the female for that purpose. The variety ‘Costata Romanesco’ Squash has more flowers than other varieties.
In general, the smaller the size, the more tender flavor.