You probably think you already know how to grow a zucchini plant but if you live in North America ... you might not. Here's a way of growing zucchini to make your plants live longer, take up less space and produce more.
Zucchini is touted as one of the easiest and most prolific vegetables you can grow in a home garden. And that's mainly true.
Planting zucchini can be done by any fool. You stick a seed in the ground, go inside to watch television for a few weeks, come back outside and BOOM you have a zucchini plant.
But there are a few things about growing zucchini that you probably don't know. Even I, who has a 40' x 40' vegetable garden, who is a contributing writer for The Old Farmer's Almanac, who grows almost all of her own vegetables, didn't know these things until a few years ago.
1. Zucchini need to be pruned and staked. For real. Like you prune a tomato.
2. Zucchini can be planted VERY close together. 1 per square foot.
3. Powdery Mildew CAN be halted.
The most interesting fact about zucchini is they can do complex math equations.
No they can't. We're very alike zucchini and I.
If you're looking for a really rewarding challenge that's a little more mysterious than zucchini take a look at my expert tips on how YOU can grow luffa sponges at home.
Table of Contents
Growing zucchini
- Zucchini are a summer squash so these tips and techniques can be applied to any other summer squash like yellow, crookneck or patty pan.
- Seeds or seedlings can be planted into warm soil at the start of summer (typically the end of May).
- Zucchini fruit develop around 50 days after planting. Once the fruit form, zucchini grow very quickly - especially if it's hot out and they get plenty of water.
- Zucchini don't need a lot of soil amendments. Add 2-3 inches of mature compost on top of your planting site and you'll be rewarded with enough zucchini to fill a clown car.
When to plant Zucchini
- Zucchini are heat loving plants so wait until your soil temperature is above 65℉ (18ºC) to plant out seeds or seedlings.
- You can plant 2 weeks earlier if you lay plastic mulch on your planting area which will increase the temperature of the soil below by 10 degrees. Garden centres sell black plastic mulch, which is often biodegradable but any black or clear plastic will work. Get biodegradable black mulch here.
- Planting 2 weeks earlier also means you will be harvesting 2 weeks earlier!
- If you're starting seeds indoors, plant them 3 weeks before your last frost date.*
Because zucchini grow so quickly and don't always transplant well there's really no need to start them inside. They usually do better when direct sown under plastic mulch. Just cut an X into the thermal plastic and push the seed down into the soil through it.
Where to plant
- Zucchini needs to be planted in an area that gets 6-8 hours of sun per day.
- Plant near companion plants like beans and peas (which fix nitrogen into the soil).
- Surround zucchini with pollinating flowers like borage, catmint, dill or dahlias to attract pollinators to that area of the garden. (zucchini need pollinators to hop from their male to their female flowers in order to produce fruit)
How to plant zucchini
Supplies
- Zucchini seeds or seedlings
- Large pot or 1' square of soil
- Water
Instructions
STEP 1 - Make sure your garden is weed free and rake it smooth.
STEP 2 - Apply a 2-3" layer of compost on top of the soil and rake smooth. If you're laying down plastic mulch to speed up your planting and harvest date, now is the time to do it.
STEP 3 - When the soil registers 65℉, plant seeds to a depth of 1" which is about the distance from the tip of your index finger to your first knuckle. For seedlings, plant them so the soil line of the seedling matches the soil line of the garden. Then push the seedling down a little to firm it and add more soil to fill the space if needed.
STEP 3 - Cover the seed with soil and water well. Make sure the soil doesn't dry out at all until you see the seeds sprout.
STEP 4 - Maintain moisture for the rest of the summer with at least 1" of water a week. Zucchini LOVES water. And don't worry about getting water on the leaves. Water doesn't exacerbate or cause powdery mildew. In fact, water helps wash it off of the plant. Powdery mildew is triggered by dry conditions - not wet.
THESE are the two tricks to growing zucchini better than anyone else: staking & pruning.
How to stake zucchini
Growing zucchini vertically might not be your first thought but it's exactly what you should do.
North American gardeners haven't really adopted this technique yet but it's common in Europe.
STAKING
- Drive a 4-5' stake into the ground before planting, so you don't damage the roots. I use lightweight coated metal stakes.
- Plant your seed or seedling right next to the stake so as it grows you can tie the stem to the stake.
You may not have noticed it before, but a zucchini plant only has one stem. That stem is just usually sprawled and dirty on the ground covered in decaying leaves. So you can't get a good look at it.
But trust me. Zucchini have one stem, that can be staked just like a tomato.
The earlier you do it the easier it is though.
Above you can see a zucchini plant that's only been staked and tied once, earlier in the season with the rest of the growth just flopped over. The leaves are being eaten by bugs, there's no air circulation and the lower leaves near the soil are getting powdery mildew.
Here's the same zucchini plant after staking it properly and removing all the lower leaves.
Just like tomatoes, zucchini benefit hugely from pruning. They'll be susceptible to less disease, have a more open formation that allows easier access for bees to pollinate and they'll take up less space.
How to prune zucchini
Why prune?
- The developing zucchini gain all their energy from ONLY the leaves growing above them. The leaves below, are just taking energy away from the rest of the plant.
- Pruning away diseased and damaged leaves helps prevent and slow powdery mildew by creating greater air circulation.
- Pruning away the larger, lower leaves that aren't contributing to the plant means you can plant more zucchini in a smaller space.
- The flowers are easier for bees and butterflies to access.
PRUNING
- Locate the lowest growing zucchini on the plant.
- Cut off all of the leaves growing from the stem below that zucchini. Cut right close to the stem.
- As the plant grows continue cutting off any leaves that are below the lowest growing fruit.
Fun Fact
Zucchini leaf stems are hollow UNTIL they get to the stem of the plant. There they turn solid again. Prune your zucchini leaves right up to the stem of the plant so you don't have any of the hollow stem left.
- Hollow stem portions can harbour disease and bugs so make sure you get right close to the plant stem when removing the leaves.
Pre staking & pruning
Post staking & pruning
See the difference from the left photograph and the right one?
Spacing Zucchini
Plant zucchini 1' apart. Rows should be spaced at 1.5' apart.
A lot of guides tell you to place zucchini plants at least 24" apart. You don't need that much room between them.
If you're staking & pruning them this is all the room they need.
Unpruned zucchini
Pruned zucchini
SOME MORE GOOD VEGETABLE TIPS FOR YOU
SAVE Your Zucchini and Squash from Squash Vine Borer
My Leek Growing Technique - Based on Eliot Coleman's
Make Paper Pots with a Wine Bottle
Make a Soil Grader for Levelling Your Garden from a Wood Pallet.
Disease
Powdery Mildew
- It's the kiss of death for zucchini plants, but luckily it's a long, slow, torturous death.
- Most zucchini plants seem to be able to withstand powdery mildew for quite a long time - months even.
- To help prevent powdery mildew, stake and prune your zucchini like I've shown you.
- If you notice powdery mildew has made its way onto your plants you can spray with this homemade Powdery Mildew spray for zucchini. It's just vinegar and water but it works.
Pests
The number 1 killer of zucchini plants are squash vine borers. These maggoty stem eating bits of grossness can kill a plant before you even realize it's sick.
Squash vine borers bore their way into the stem of the zucchini along the soil line and then proceed to eat the entire plant from the inside out.
There's usually only one vine borer per stem, so all you have to do is check your stems for signs of it at the end of June and into the summer.
I have a whole post on how to remove squash vine borers from your zucchini, winter squash, pumpkins and other gourds.
How to Grow Zucchini Plants
How to grow zucchini plants the right way! And I bet it's different than how you're doing it now.
Materials
- 4-6' long stakes
- twine
Tools
- scissors or knife
Instructions
Plant your zucchini 1.5" apart. They aren't going to need all kinds of room to grow and sprawl anymore because you're growing them UP.
Plant a stake right next to the main stem of the zucchini plant.
Using string or twine tie the plant's stem to the stake so it grows upright.
Remove all those huge leaves that are growing at the base of the plant (only the leaves below any developing fruit)
Monitor the plant once a week to see if you need to tie it to the stem again as it grows.
Notes
Zucchini should be grown basically like tomatoes! Stake them and remove older leaves that aren't doing anything productive for the plant other than making it vulnerable to disease.
Staking is easiest if you do it when the plant is first put in the ground, but you can wrangle an older plant into submission as well.
Cut your leaves off as close to the stem of the plant as you can.
If you see signs of powdery mildew developing you can wash the plant. Yes. Wash it with water. Powdery mildew HATES water and thrives in dry, hot conditions.
Powdery Mildew can also be controlled (not cured) with this simple spray recipe:
4 cups of water + ½ Tablespoon of Vinegar.
Spray the top and bottom of the leaves once a week.
Zucchini can be picked at any time. All sizes are edible. Yes. Even the big ones. Larger zucchini will need their seeds removed.
Absolutely. Zucchini are perfect for pots, especially if you use this staking and pruning method to control their size.
Zucchini season runs from June to August. The plant begins to produce fruit around 50 days after planting. To extend your season, plant first at the end of May and then again at the end of June. This way if you lose plants to disease or pests, you'll have another crop on the way.
If your zucchini grow to about the size of your pinkie finger, and then rot and fall off you have a pollination problem.
This is caused by the female flower (which has the fruit) not being pollinated by the male flower. You either need to attract more pollinating insects to your garden OR I can show you how to hand pollinate.
Apply what you've learned here and you'll have your biggest zucchini crop ever.
You might be wondering why would you want them to produce even more? Zucchini are already insanely productive. Well, because of the obvious. They’re fun to throw through people’s open car windows during zucchini season.
Zucchini may not be able to do complex mathematical equations but they can add up like nobody's business.
→Follow me on Instagram where I often make a fool of myself←
Joanna B
This is a game changer!!!! Best zucchini year yet! Fortunately I found this post after purchasing my newbies at the nursery and I can say this has been (so far!) The only year my zucchini haven't has mildew. Only problem so far has been the usual aphids. Try out her cage free tomato string method as well. Another excellent find this year. Thank you!!
Karen
Hi Joanna B. I'm glad the tips are working for you! :) Happy gardening. ~ karen!
Cecelia
Hello
My first year growing zucchinis, thank you for the tips.
Do you have any tips for cutworms? I had a beautiful zucchini started and one morning it was cut but those little)$&@!
I sowed some more, with half toilet paper rolls around them.
Tonight, I ll pour some dish water on my seedlings, I hope to at least get one plant! 🙄
Karen
Cutworms are infuriating! I'm a bit worried the toilet paper will just rot. If the stems are small enough use a straw (the big fat kind like you get from a fast food place) and cut it lengthwise to make it easily slip around the stem. Make sure it sticks into the ground about an inch. This will help because the plastic won't rot away or fall over, plus it's closer to the stem so there's less chance that a cutworm will come up from the soil between the barrier and the stem. ~ karen!
Mandy
If Zucchini is already pretty established do you need to tie it further up or only the one at the bottom? Can you do the same for squash and any recommendations to keep squash bugs permanently away? I’ve been killing the eggs but these little suckers won’t go away.
Karen
Hi Mandy. You have to keep tying it up as the stem grows. You can't use this method for winter squash because they're so much larger and vigorous plants. For squash bugs, I just squash them and also tear the portion of the leaf with eggs off. You can try Neem Oil if the problem is really, really bad. 1/2 tsp Neem Oil in 2 cups of water and spray. ~ karen!
Jacqueline Divino
When staking 4 of my zucchini plants I accidentally partially severed the main vine of the largest one. It had gotten quite heavy. I continued the staking; the vine is still attached but weakened. I am now worried I have damaged the plant beyond help. Any thoughts? I am leaving it alone to just see how it does but not optimistic.
Jenny
I usually plant 2-3 zucchiy seeds in one spot, in case they won't all germinate, though often they all come up. The plants kinda each go their own way and spread out. I already planted mine but am going to stake because they are still fairly small and I just learned about this. Simcey each hill seems to have 2-3 plants, should I dig one up and spread them out? They seem way to close together for staking. Just worried if I move them they'll not transplant well since they're already in the ground (and not coming from a tiny seedpot)
Janice
Can you tell me what you use as ties? I don’t want to use anything that will cut into the plant. Thanks
Tracy
I am a novice Gardner , first time trying various vegetables in a raised bed and containers. I have been on You Tube and reading as much as I can. And my questions are many times so silly to me. For instance, how do you tell male from female flowers on a zucchini plant. Once I know that maybe I can pollinate because my plants have produced nothing so far. Thank you!!
Elle
Is this the same for yellow squash as well?
Karen
Yes it is. ~ karen!
Dave P
I would be very careful about trimming yellow squash plants. Maybe I was too aggressive and trimmed too much. Or, maybe I should have waited until the plant actually produced usable squash. After trimming the unnecessary leaves, my plant withered up. And, it's not for lack of water as we've just emerged from several days of rain.
Dave P
I was wondering this, as well. I'm staying vigilant for the borers. I've squashed (no pun intended) many of the moths recently. Now I know what to look for after reading the article about the borers.
Luci Stoddard
Hi Karen,
Thank you for the great information about zucchinis! I’ve been gardening in our new home in MD for just a few years now - it’s a great growing season here, and I’ve had mixed luck with my zucchini. Last year it just wilted away and died, I planted it a second time and the same thing happened. The year before it was very prolific! I will try staking it this year, my question is how did you tie up the leaves? They don’t look tied to me at all, it just looks like the stake is placed in the middle of the plant and the bottom leaves trimmed. Thank you!
Karen
HI Luci. If it wilted away and died (fairly quickly), chances are you had vine borer. I have a post on that here. https://www.theartofdoingstuff.com/squash-vine-borer-control/ ~ karen!
Greta Johnson
Vine borers eventually take out all my zucchini even though I try to be on top of it and cut out/kill the grubs and pack wet soil over the wound. I finally gave up growing the typical type of zucchini. I now grown Tatume squash. It is a vining type that has oval/round, nutty tasting squash much like zucchini. It is commonly grown in the Mexicos and Texas. The plus and minus of it are this:
pluses: heavy production till frost
smaller, harder vines that do a MUCH better job repelling vine borers
wonderful flavor/ideal shape for stuffing
heavy blossom production for eating the blossoms
leave them on the vine to ripen and they make delicious "winter" squash
they are open pollinated, so one can save their own seeds for the future plantings
can be grown up a trellis
Cons: Take up a lot of space with their prodigious vines, but vines root at many of the plants nodes
nodes, so if a vine borer does succeed, you can simply cut off that part of the vine
and it continues grow and produce without interruption
Years ago I ran an organic market gardening business and customers couldn't get enough of these!
If
Jeff
What about Summer squash? Can they be staked like this? They seem to be so much like the green ones and grow just like this so I am hoping the answer is yes.
Karen
Hi Jeff. Yes, summer squash can be staked like this. Winter squash, cannot. :)~ karen!
Cara
I am so doing this this year. My past few years I have had horrible powdery mildew. I hope this helps. Thanks for sharing
Jeff
I use Garden Safe Brand Fungicide3 for powdery mildew. It is organic. I didn't choose it because it was organic. It seems to be the only thing that helps. My plants still get the mildew but it seems to slow it down. I am growing yellow squash, gourds and cucumbers.
Cassie
Hello,
How early can you start pruning the leaves?
I see that you have to prune under the zucchini but when do you start pruning-when you first see an actual zucchini or can you start earlier when you see flowers about to form?
I am a novice if my question seems worded in non gardening terms!
Thanks!
Karen
Hi Cassie! Just leave the leaves so the plant can gather as much energy as possible until fruit starts to form. :) ~ karen
Keri
What material would you use to tie the plant to the stake?
Karen
Hi keri. I honestly just use whatever string I have around, but anything that's not biodegradable is best because cotton string or anything like that can degrade before the summer is over. I usually use green nylon string that I reuse in the garden year after year. ~ karen!
Tiffany
I have a question. I have one large zucchini plant and 5 small ones. They were all planted at the same time, but for some reason 5 of them haven’t grown like they should. They look fine and are starting to bloom . Any idea what could be going on?
Karen
HI Tiffany. If they're really small you should remove the blooms because it sounds like they're not ready to set fruit and you don't want their energy going towards making fruit when it needs the energy to increase the size of the plant. It's possible they just got a little bit of shock at some point and that slowed their growth. ~ karen!
Guy Harrison
Hi Karen,
Thanks for the article. I am growing heirloom zucchini for the first time (a Bonnie variety) and am noticing that I am getting secondary stems on my plant. Should I be cutting these off like I do the suckers on my cherry tomato plants?
Thanks!!
Karen
Hi Guy! Are you certain that they're secondary stems? If it's an heirloom zucchini it must be Black Beauty. There shouldn't be any secondary stems but sometimes it's easy to think that's what's happening because it can look that way when the zucchini is setting fruit and growing new leaves and flowers. Double check just to make sure. So at this point, no I wouldn't be trimming anything off. :) ~ karen
Mary
But I’m confused if you have toes cut the leaves blow the first fruit do you obviously wait until it starts bearing fruit
Madison
I'm so excited to try this this year. I have a dumb question though, does it matter what you use to tie up the vine on your stake? I'm worried about strangling the plant.
Also, has anyone tried this with Spaghetti Squash? Thanks
Madison
Just kidding, I just saw a previous comment on Spaghetti Squash.
Karen
Oh, lol. ~ karen!
Karen
Hi Madison! This technique is meant for summer squash. It won't work for winter squash which have much longer and vigorous vines. You can use anything to string it up as long as you don't tie it so tight that it cuts through the vine. I use a lot of nylon string because I can use it over and over again in the garden whereas twine, though biodegradable, will sometimes fall apart before the season is even over. ~ karen!
Debbie Conley
Hey Karen
Just needed some clarification. On planting you wrote a foot apart in 1.5 inch rows? Did you mean a foot apart in 1.5 foot rows?
Thanks
Karen
Yes! Thanks for the correction, I'll fix it. ~ karen!
Irene
Can you tell me how to get started with zucchini plant lease. Is it from seed or a part of actual zucchini
Karen
Hi Irene. I'm happy to help but, I'm not sure what you mea by "zucchini plant lease". ~ karen!
AkSonya
Thank you, the tip I didn't know I needed. Here in Anchorage, Alaska we are the land of the midnight sun so I am bless to grow zucchini the size of watermelons.
I am excited to try your staking trick so I can double my space. I use the square foot method and give them 2' each, you just gave me a lot of real estate back, thank you very much. I am excited to see if my zucchini and squash will be bigger now with having more air and less leaf issues.