Growing Summer Squash (Zucchini)

Planting, Growing, and Harvesting Summer Squash

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Summer squash, especially zucchini, are a garden staple and vigorous grower. Each plant will produce several squash a day during peak season! But that doesn’t mean they’re trouble-free. In our Squash Growing Guide and video, we’ll share tips and tricks to sidestep common squash problems, as well as tips on how to harvest and cure, so you have a successful squash season!

Chances are that you’ll end up with more zucchini harvest that you can handle. But that’s OK! See our recipes below for all the different ways you can enjoy (or preserve) zucchini. Plus, zucchini is full of nutrients! You can’t go wrong…unless you forget to harvest and end up with giant baseball bats! (More on how to harvest later.)

Squash are generally divided into two categories based on when they’re harvested and how they’re used:

Summer squash are warm-season crops harvested in the summer before they reach full maturity. Because they’re harvested early, their skin is edible and they have a relatively short shelf life. Summer squash varieties include zucchini, yellow squash (straightneck squash), and crookneck squash.
Winter squash are harvested in autumn after or just before they reach full maturity. This leaves their skin inedible, but gives them a longer shelf life (some varieties are capable of keeping through the winter—hence the name “winter squash”). Winter squash varieties include pumpkins, butternut squash, spaghetti squash, and acorn squash.

Most summer squash now come in bush varieties, which take up less space, but winter squash are vining plants that need more space. Bush varieties will need to be thinned in early stages of development to about 8 to 12 inches apart.

Thanks to their regular bumper crops, you usually only need one or two zucchini plants—and you may still find yourself giving zucchini away to neighbors or baking lots of zucchini bread!

A Common Ancestor

Would you believe that pumpkins and zucchini come from the same species of plant? That’s right—they’re both cultivated varieties (“cultivars”) of Cucurbita pepo. Despite the great diversity of squash, most commonly-grown cultivars belong to one of three species: Cucurbita pepo, C. moschata, or C. maxima. Over generations and generations, these plants have been cultivated to produce fruit in all kinds of shapes, colors, and flavors.

Planting Dates for SQUASH (ZUCCHINI)

Planting Calendar for all Plants

Planting

When to Plant Summer Squash

Sow squash seeds directly outside at least a week after your last frost date. The soil needs to be warm (at least 60ºF/16°C at a two-inch depth). The Garden Planner will calculate your exact planting dates for squash based on your location.
If you wish to start seeds indoors, sow 2 to 4 weeks before your last spring frost in peat pots.
Warm the soil with black plastic mulch once the soil has been prepared in early spring.
Do not rush. Waiting to plant can help to avoid problems from squash vine borers and other pests and diseases common earlier in the season.

Choosing and Preparing a Planting Site

Pick a spot with full sun, shelter from wind for good pollinations, and well-draining soil.
Squash plants are heavy feeders. Add plenty of garden compost or well-rotted manure to the soil before planting.
When you plant their holes, scatter in some organic fertilizer as well.

Learn more about soil amendments and preparing soil for planting.

How to Plant Squash

Sow seeds in the ground about 1-inch deep and drop in 2 seeds. Pop a clear jar or half a plastic bottle over the top or use a cold frame protection in cold climates. Leave until the seedlings are up, and then remove the jar, and remove all but the strongest seedling.
Alternatively, plant as a “hill” of 3 or 4 seeds sown close together on a small mound; this is helpful in northern climates, as the soil is warmer off the ground. Allow 5 to 6 feet between hills.
If you wish to get a head start: Sow under cover in a greenhouse a couple weeks earlier. Fill small pots or seed trays with potting mix and sew one seed in each pot. Prepare small plants for life outdoors by “hardening off.” Set the pots outside for a week or two for a short time and increase the length of time. Plant after no risk of frost.
Plant squash at least 2 feet apart. (The Garden Planner will calculate spacing for you.)
Thoroughly water after planting.
Adding a layer on top of mulch (such as garden compost) to lock in soil moisture.

Demo: See How to Grow Zucchini and Summer Squash

Care

How to Grow Summer Squash

Squash thrive in moist soil. Water very thoroughly whenever it’s dry. For all types of squash, frequent and consistent watering is important for good fruit development. Water most diligently when fruits form and throughout their growth period. Water deeply once a week, applying at least one inch of water. Do not water shallowly; the soil needs to be moist 4 inches down.
Remove any weeds that manage to poke through. To keep plants tidy, cut off any dead or shriveling weeds.
Top up mulches, using organic matter such as garden compost, to help roots stay cool and moist.
When the first blooms appear (which will be male flowers), apply a small amount of fertilizer as a side dress application. After harvest begins, fertilize occasionally for vigorous growth and lots of fruits. If your fruits are misshapen, they might not have received enough water or fertilization.
- Tip: If your weather is cool, damp, or you’re not seeing pollinators, you can hand pollinate your squash blossoms for better yields.

Pests/Diseases

Pesky pests, diseases such as powdery mildew, accidental damage, and incorrect harvesting and storing can all take their toll on your crop.

Two troublemakers often pay an unwelcome visit, usually early in the season. The best solution is to get ahead of them before they arrive.

Squash bugs feed on sap, weakening plants and threatening fruit production. Protect plants when the bugs are most active, early on in the summer, by using row covers or fleece. Then continue to check for eggs at least twice a week. Rub or scrape off the eggs. Adult bugs can be knocked or shaken off plants into a bucket soapy water. (If you keep chickens, offer them a treat!)
Squash vine borers are found in the eastern half of North America. They burrow into stems, causing them to rot and foliage to wilt. They are most active earlier in the summer. Row covers can help keep them off, or wrap stems in foil to prevent eggs from being laid at the base of plants. It’s possible to cut the grubs out by making vertical cuts into the stem using a sharp knife. Once you’re done, bury the stem with moist soil to encourage new roots.

As far as diseases go, powdery mildew can be an issue on the leaves later in the season. It’s a common fungal disease that forms a white powdery coating on both sides of leaves. Keeping plants well-watered and leaving plenty of space between them for good air flow should slow the spread of this disease. If your squash does get powdery mildew, don’t worry about it; plants will usually cope.

In worst cases, powdery mildew stalls growth by preventing leaves from absorbing enough sunlight. A common reason for powdery mildew is irregular watering, which stresses plants, leaving them more susceptible to infection. If plants do become infected, remove affected leaves straight away. A great way to prevent powdery mildew altogether is to mist leaves with a solution that is ⅓ milk to ⅔ water.

Spray the milky mixture onto all surfaces, early on a dry and sunny day. Repeat every 10 to 14 days throughout the growing season.

Blossom-end rot is an occasional issue as well. If the blossom ends of your squash turn black and rot, then your squash have blossom-end rot. This condition is caused by uneven soil moisture levels, often wide fluctuations between wet and dry soil. It can also be caused by calcium levels. To correct the problem, water deeply and apply a thick mulch over the soil surface to keep evaporation at a minimum. Keep the soil evenly moist like a wrung out sponge, not wet and not completely dried out.

Fruits left on the ground can get blemished or rot in wet weather. Slip a tile or slate under the young fruits as they begin to swell. Sprawling varieties of squash look stunning on vertical trellises, but be careful to support the fruit as they get large. Tie a sling into place with fabric or old tights. (See video below.)

How to Avoid Common Squash Problems

Watch this excellent video for tips and tricks to sidestep common squash problems so there’s no barrier to your successful harvest!

Harvest/Storage

Havesting Summer Squash

Summer squash and zucchini are harvested the moment they reach a usable size. Just cut them free and store in the refrigerator up to a week.

We harvest summer squash when the fruits are quite small (about 6 to 8 inches) Smaller fruits are more tender and flavorful with a denser, nuttier flesh. Believe us, smaller fruits have a far superior taste. If you have ever had a negative experience with zucchini before, it’s probably because they were left to become bruisers.

Plus, picking frequently leads to a larger crop. Check zucchini and summer squash EVERY DAY once the plant gets going.

Most varieties average 60 days to maturity, and are ready as soon as a week after flowering. (Check the seed packet for more exact information.)
Cut your squash from the vine with a sharp knife rather than breaking them off. Leave at least an inch of stem on the fruit.
Should you miss a picking or two, remove the overripe squash as soon as possible to reduce demands on the plants for moisture and nutrients.
Summer squash is very susceptible to frost and heat damage, so you do want to pick them all before the first fall frosts arrive.
Store unwashed in the refrigerator until you’re ready to use. Fresh summer squash can be stored in the refrigerator for up to ten days.

Recommended Varieties

Summer Squash

‘Cashflow’: cylindrical zucchini type
‘Cocozella (di Napoli)’: zucchini heirloom; dark green, slender
‘Goldbar’: yellow summer squash
‘Horn of Plenty’: yellow crookneck type
‘Sunburst’: pattypan/scallop type
‘Tigress’: zucchini type

Wit & Wisdom

Squash flowers are edible and make a tasty treat when fried in a light batter.
Pumpkins and other squashes are nutritional powerhouses! Learn about squash’s health benefits.

Recipes

Cooking Notes

Zucchini can be overwhelming once it starts producing. If you have too much to use, see tips for freezing zucchini. Find more of our Best Zucchini Recipes for ways to use this abundant crop!

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Reader Comments

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Squash production

I've planted Zucchini for several years. This year since my 125 year old American Elm died last year, I moved my garden to a sunny spot where nothing grew under the tree before. My Zucchini plant is about three times as big with leaves over two foot wide but only about one zucchini every three days. This is my first year for Acorn squash the vines are several feet long with several squash. What is with the Zucchini if others are producing?

one zucchini every three days

Can’t help myself; have to ask: how much is enough? One zucchini every three days sounds like a healthy harvest. An excess of nitrogen in the soil can lead to (exceptionally) large foliage in lieu of fruit but you’ve got the fruit and the foliage. Next year set out more zucc plants.

Zucchini...can I train to grown on supports/cages??

Planted just one this year and it’s coming along nicely. I put a cage around it early ...in an attempt to keep it from taking over my small 6’x12’ garden allotment. Will it work...or should I remove the cage now?

growing zucchinis vertically

Yes, you can definitely grow zucchinis in cages! Older varieties may have a more vining habit while newer cultivars tend to be the bush type. In either case, be sure that the cage is a good size for the plant habit, and is secure (perhaps supported by stakes) so that it won’t topple with the weight. You may need to loosely tie a few stems to the cage wire to help. Also make sure that you will be able to easily harvest the zucchinis (wide enough mesh or top opening). In addition to saving space in the garden, growing zucchinis vertically helps with air circulation, which helps to prevent disease. It also gets the squash off the ground, which helps to prevent rot. Great idea!

zucchini

Years ago during the summer when I lived in Northern California you always locked your car when visiting friends. Reason was while you weren't looking someone put a bag or 2 of zucchini in your back seat. LOL

Zucchini that doesn’t look like zucchini

It is fat about 4 “ across and only 5 “ long. Dark green with white flesh and when cooked it has a tougher skin taste good. Sweet but doesn’t taste like zucchini but the plant smells like zucchini

Spagetti Squash

I have many male flowers and so few female, this is second year with the same problem.
This year I put in more plants 10 in all. I have only 5 growing on 5 plants and only in the last few weeks did they start to get large. I planted them at the end of May and June. I live in Winnipeg Manitoba . How do I get them to produce more fruit? Thank you

Cranking seed on zucchini fruit

the seeds inside zucchini fruit crank a lot. i don't know why?

Zucchini Squash monsoon season

Zucchini Squash can be cultivated during monsoon season?

Summer Squash

First time ever planting squash and I way over did it. They are out of control growing in their designated space. Can I prune them back or will that cause damage to them producing? Also, I am not seeing any fruit only blossoms. Is there a difference between male and female blossoms? Definitely learned my lesson for next season planting as far as spacing is concerned. Please help! Any information is greatly appreciated!!

Summer Squash

I am planting yellow squash in a raised garden (a truck canopy turned upside down - GREAT garden), but I need to make a cover to keep out the deer and the feral cats from using it as a litter box. I need to know how high they grow, so I know how tall to make my cover. I have never grown it before and have searched the internet and cannot find this information. Thank you.

Squash Height

Do you know which variety you are growing? The height of the plant will depend on the variety, but squash plants generally get to be about 3–4 feet tall when full mature. Making your cover 5 feet tall would be a safe bet.

Summer Squash

Where I am, we have shorter season. I use greenhouse tarp to cover my garden after I have tilled it. Use coiled wire(I buy from Dollar store) to make large staples to press into the edges of the tarp to hold tarp down. Simply cut small X's leaving the tarp and plant. Keeps out the animals and weeds and keeps in heat and moisture. Great way to extend your season too. After season simply roll up and put away for the winter. Oh I also shred the leaves around here with my mulch bagging lawnmower and till these under making a great compost. Come spring you won't even notice the leaves were there.

Surprise gift

Last year I put a whole Princess Pumpkin in a raised box, got sick and forgot it. This year I started to plant an heirloom tomato plant in that box. I put on my shovel and found the runny insides of the pumpkin. It was a beautiful orange. I just shoved it over and planted anyway. The surprise was the hundred seeds started making plants. I started transplanting plants. There are beautiful flowers just starting.
Here is my question? I would like to plant acorn squash because I know these regrow on their own and more of the winter squash if I knew they would grow. Have you ever heard of this? Does it work? I live in cold area on Oregon. This would give me a head start. Thank you.

surprise gift

First, congratulations on your success!

Here’s an attempt at an answer to what I think is your question: Acorn and other squash are annuals. They grow one season and die. However, seeds from their “fruit” can be the source of the next year’s crop; this is the purpose for saving seeds—salvaging them from the harvest. You got lucky in so far as you did not need to harvest and save your seeds; they survived on their own. That does not always happen and can not be predicted. You say you are in a cold area; that may have helped to preserve the seeds (freezing is a technique) but, again, it’s only a hunch. If you’re asking if you should plant acorn and winter squash now to allow their seeds to get going earlier next season…you could, on a bet and see what happens. Or you could plant, harvest, and save the seeds of this year’s harvest. BTW, hybrid plant seeds do not reproduce true to the original plant, so grow heirlooms.

Zucchini getting yellow and soft at flower tips

My zucchini starts to come in nicely, however, at about 3-3.5" in length the flower ends begin to turn yellow and become soft. What am I doing wrong? I have had to remove 3 zucchinis from the plants. Others are growing and I want to avoid having problems with those.

zucchini rotting on the vine

It sounds like blossom end rot, an unfortunately common occurrence due to excess moisture and inadequate calcium in the soil. See here for more specific information: https://www.almanac.com/pest/blossom-end-rot

Female flowers

I have a zuchinni plant that has so far only bloomed female flowers. I have 2 females so far and it looks like the next one to bloom will also be female. They have 2-3" fruits on them but they don't seem to be getting bigger since the bloom opened. Should i be concerned?

It sounds like they have not

It sounds like they have not been pollinated. If you don't have bees to move the pollen from the male flowers to the female ones, the fruit will not continue to grow. You can do this with a Q-tip or other small object. I have never had a zucchini that did not have male flowers along with the female ones, this is a necessity for the fruit to continue to grow.

Powdery mildew

I am having a hard time with a couple of my zucchini plants already. My plants are less then a month old and I think a couple already have powdery mildew. They are in a raised bed. I made sure to prep the soil, added compost and manure, etc but yet 3 out of my 6 squash plants are showing signs of disease. I have Battled PM but this time it looks different. The leaves are growing with white along the veins. Is it still mildew or am I doing Somethjng wrong? The size of the plants are beautiful and all my other plants are growing well. Please advice.

Ps. I did use a copper fungicide and it helped one of the plants.

powdery mildew causes and cures

We think you have identified the problem. See these pages for more information:

• How to identify—and confirm—that it’s PM: https://www.almanac.com/pest/powdery-mildew

• More pictures/examples of PM and remedies: https://www.almanac.com/blog/gardening/garden-journal/powdery-mildew-rem...

Winter & Summer squash

I am planting a three sisters garden in the arid southwest. I would like to have a combination of summer and winter squash. My corn is about 6 inches tall and I am ready to sow squash and beans. Can I plant both summer and winter squash in the same garden? With moderation of course...

Squash

Yes, there’s no reason not to plant more than one type of squash if you have the space.

Stunted growth

I live in growing zone 9 but it has been unseasonably cool this spring. I planted my seedlings of which most were very slow to germinate. All have finally germinated however each plant has been so slow to grow and are rather stunted. I just noticed that the plants, while still very small are trying to produce flowers (of which I know will yield a very poor crop of any at all). Now that the temps are a bit warmer, should I just start over and replant or will the existing plants eventually recover?

chilly squash

It’s hard to say, but they might possibly recover fine if the temperatures keep on the warm side, although there is the possibility that they may not be as vigorous. You might pinch off just these early flowers, so that the plant can focus on growth. You could also certainly add a few new plants, though, to be sure of a good harvest.

I would suggest keep trying

I would suggest keep trying with the plants you have. If you want, go ahead and plant one more to see which one seems better, but I have zucchini started in a little 6" pot, and since the warmer temperatures have come around, they are definitely starting to thrive more

Yellow crookneck squash

In Florida can squash planted in august do well ? Thank you.

planting dates for squash

See our planting dates for summer squash customized to your zip code here: https://www.almanac.com/gardening/planting-dates

Albino squash?

I've had two white squash grow on the same plant. They are about the size and shape as a butternut but one is pure white the other pure white with a very slight yellow stripe on it. I have no idea what kind they are or when to pick them. Any suggestions?

white squash

Another grower asked this question a bit ago (scroll) to see. Short answer: it is likely a mutation. The squash is fine to eat and will taste like any green one—yummy!