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. This growing guide will fill in every blank and answer most of the questions you've ever had about zucchini.
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 didn't start using this technique until a few (maybe a decade actually) 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 but remember to make sure your soil is amended for that. (lots of compost or some organic fertilizer)
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←
Shiela Foreman
Do summer/yellow squash benefit from growing like this? How about bush cucumbers?
Karen
Hi Shelia. It does work for summer squash since they grow the same way. For a bush cucumber they can be trellised but it wouldn't be quite as tidy as the zucchini. Even as a bush variety cucumbers are kindda bossy and sprawly. ~ karen!
Judy
Love this idea for growing more zucchini. Thank you. I noticed your drip irrigation. Can you tell me what you use. The drip irrigation hoses I have bought do not work. They split and some plants wind up getting flooded with water while others get little or no water. I would appreciate any advice you have. Thanks for your great tips.
Karen
Hi Judy. I have a whole post on installing a drip irrigation system!
shannon s
my grandfather would take an old hose and employ me as a small child to mark on the hose every 3 feet and then he would come by and make a small hole. He did stuff like that even before things were able to be purchased in stores. It still works. The cheapest hose you can find will work.
Kirsten
Based on your article, I’m going to give zucchini one more try. I also have the problem of the ends yellowing and then rotting. Is it lack of calcium?? Any tips?
Melissa
I had that trouble too last year. After much googling, it was decided that either it didn’t have enough calcium OR the flowers weren’t getting pollinated. About mid-July I started hand pollinating the zucchini blossoms, and then I was overwhelmed with zucchini! Might be worth a try for you too. 😁
Laurie
Are the zucchini shown here the bush type? Do you have any recommendations for gorwing the vining type? Maybe a trellis?
Thanks!
Courtney
Hi there! A little confused on the spacing instructions. Are you truly saying 1' (1 foot) apart and in 1.5" (1.5 INCH) rows? Or did you mean 1' (foot) apart in 1.5' (foot) rows?
Looking forward to trying this. thank you!
Carl Prather
Numerous people have asked this question with no reply. Normally spacing between rows is 1.5 time the distance between plants in most planting instructions that I've seen. I intend to try this method, but will use 1' and 1.5 ' as planting distances.
Jennifer Bolton
Hi there,
I will definitely be trying this for my zucchini. I always seem to have a great harvest, but would love to save the room for other plants. I always seems like zucchini takes too much room. I am curious about your water system. We have tried a couple of ways, but didnt seem to have great luck last year. It was a very undeasonable HOT, DRY summer so that could contributed, but curious how you have your set up for garden boxes.
Rowan
1' apart is probably a typo. I assume they are 1" apart.
Erin
This is revolutionary!!! Thank you!
Do you think it would work with pumpkins?
Rhonda Brookens
Can you do this with yellow summer squash? Also do you have any tips on getting rid of squash bugs?
Karen
Hi Rhonda! You can do this exact technique for any summer squash. :) I mainly ignore squash bugs but you can use Neem Oil on them. I have a post on controlling squash bugs here that you can take a look at. ~ karen!
Tinker Iddins
You must have a great arm, throwing all those zucchini through open car windows! If I didn't lock my car in the 70s, there was a good chance of coming back to a full size grocery bag full of bowling pin size zucchini!
Thanks for the great idea, served up with wonderful humor!
Karen
You're very welcome Tinker! ~ karen
Nasreen Kabir
I cook the zucchini leaves too.
Freda
I heard that if you get to many male flowers and not enough female you should cut some of the male flowers away do you think so? Mine are 2 to 3" and turn yellow also. But your advise on pruning should help. Do you water a lot? I see your drip hoses.
Kat - the other 1
I just picked and ate my 6th home grown zucchini of the year!
Which is at least twice as many as I've ever gotten before!
I thought when I put the plants out this year that it was string training for both tomatoes and zucchini... it is difficult to string a zucchini, but I did it! Lol!
Between that and trimming back the leaves it has done so much better than any other year!
I usually get 1 - 3 inch zuke, then the plant gets grey and fuzzy and dies. :(
Next year ill definitely try a stake instead, lol.
Thank you for sharing!
I read your supposed to pick them every day, but I'm only getting one a week. I wouldn't mind 2-4 a week, especially since mom's been stealing them, but , I'm getting 1 a week! Yay!
So much more than ever before. :)
Kat - the other 1
I spoke too soon and jinxed it. The bugs ate it right after. :( *cries*
Marty
Cool beans! Well, cool zucchini! I always wondered why I ever got few zucchini and always got mildew! I just gave my 3 plants (unfortunately planted in a mound together) a leaf-cut, and I’ll make a Mildew “dressing” to keep it at bay. Thank you Karen, I always learn something from you, win, win! You rock.
Kat - the other 1
Stupid question incoming...
What about the teeny tiny itsy bitsy pumpkins?
Or the the fist sized ones?
Surely being so much smaller it might work??
Ps. Never grown pumpkins yet... on purpose. lol.
Karen
Hi Kat! Those don't work because they grow on a different kind of sprawling vine that can get 12 or 14' long. And then those stems have multiple branches that branch off of them. Whereas a summer squash (zucchini in this case) has 1 single stem that doesn't grow to great lengths. ~ karen!
Kat - the other 1
Oh! Ok. Thanks!
(For answering my stupid question ;)
Bruce Williams
Well, zucchini may not have shown their ability at complex math... yet, but apparently a type of one celled animal, affectionately though inaccurately called a slime mold, has. Here's a link to a fascinating article about it:
https://www.sciencealert.com/this-creeping-slime-is-changing-how-we-think-about-intelligence? utm_source=pocket&utm_medium=email&utm_campaign=pockethits
Karen
I refuse to read an article where a single celled animal is smarter than I am.😆 ~ karen!
Bruce Williams
Now, now.., don't be chauvinistic - do you resent monarch butterflys for their astonishing navigational abilities, do you? Come on, give the slime a chance; it really is very interesting. I could also send you an article about the intelligence of the forest ecosystem that's also pretty amazing... Intelligence seems to come in a variety of interesting packages. Cheers!
Donna
Thanks for this info. I’m going to try it. In one of the photos there is a white tent in the garden. Im looking for something like this for my broccoli and cabbages. Can I ask where you purchased this?
Thanks
Karen
Hi Donna! I built all the structures in my garden and I have a LOT of things covered up like that, lol. This particular structure is just lengths of bendable PVC conduit from the hardware store stuck into the ground to form a hoop. To make the hoops more secure I hammer 2' lengths of rebar into the ground which the PVC pipes can fit overtop of. 1' or so of the rebar is hammered into the ground and then the pipe just slips over what's out of the ground. It makes the hoops very stable. I run a few of these over the bed and then cover with row cover like this. Hope that helps. ~ karen!
Shelley
Thank you for this! This year I am Trying this method for zucchini and the string method for tomatoes. I live In the Pacific Northwest so growing season is in full swing… so far, so good!!!
Charlie Davies
Hi there
Not sure what happened, I posted a comment to ask if you can do this with Pumkins but it doesn’t seem to be showing?
Karen
Hi Charlie! Well I'm not sure what happened. :) But I can tell you that it won't work with pumpkins. Their vines are too long and sprawling. :/ ~ karen!
Charlie Davies
Ok, thank you 😊
Charlie Davies
Don’t know if this is of use to you Karen, but I found this video on YouTube for growing pumpkins vertically https://youtu.be/-5NIFrh5QDI
Mary Todd
Squash Burrowers are the worst. I love zucchinis but hate these burrowers. I’m trying again this year with tying and staking, I also heard they radishes so I’m growing them almost on top of my zucchini’s and summer squash-I’ll let you know if anything helps. I hate to go through an entire 6 weeks of grown with nothing to show for it. I also heard growing marigold and Cosmos nearby help to promote happy local ladybugs who love to eat all the threats to zucchini’s and squash. I’ve grown marigolds in the past which did nothing to help my zucchinis and squashes.
Karen
Yeah. I've never seen results from marigolds yet everyone continues to plant marigolds like they're the miracle flower, lol. ~ karen!