17 Tips For Growing Great Zucchini in Your Garden
Looking to grow some great garden zucchini this season? Growing a healthy zucchini harvest is more of an art form than science. These fast growers are a garden favorite, but it's always important to maximize your yields, and there are several ways to do just that. In this article, homesteader and gardening expert Merideth Cohrs provides her top tips for growing great garden zucchini this season!
Zucchini and summer squash are a true garden staple. This is a plant that doesn’t need too much to be happy. Plant it in full sun, give it enough water, fertilize, and it provides an abundance of fruit for our occasional attention.
If zucchini is properly grown and cared for, it will produce enough fruit that you can eat it with every meal and still have plenty left over for friends and neighbors. In a time where our world is experiencing great stress and division, I’d say we could all use a zucchini plant or two that allows this type of generosity.
So with the goal of having enough zucchini to share with the neighborhood, let’s take a look at the tips that will help you grow a bumper crop this year.
Although you can start zucchinis indoors or purchase starts from a nursery, they tend to do better when sowed directly in the ground. Luckily, they are extremely easy to grow from seed and you will likely see germination within 5-10 days of planting depending on the zucchini variety.
Plant 2-3 zucchini seeds about 1 inch below the surface of the soil, cover with soil, and press down lightly with your fingers. Lightly mist the top of the soil with a spray bottle or a very low flow hose.
You don’t want to pour water over the top or use a hard spray attachment over newly placed seeds since it can wash them away or force them too far under the soil. Place seed markers at the plant sites so you don’t forget what you planted!
You can soak zucchini seeds for 24 hours prior to planting, but this is 100% optional. I’ve gotten great germination rates with my zucchini plants and have always forgotten about this step!
When the seedlings are about 3” tall and have 2 sets of true leaves, thin out extra plants, leaving only one per hole. To do this, snip them off at the soil level with a pair of scissors or shears. Thinning your seedlings allows the strongest plant to grow without competition.
Zucchini is a warm season crop, meaning it shouldn’t be planted while there is any chance of frost. Like tomatoes and peppers, it’s better to wait until nighttime temperatures are consistently above 55 degrees. This will ensure that soil temperatures are warm enough to keep your zucchinis happy.
Zucchinis are very fast growers, often producing fruit 50 days after seeding! So even if you have a shorter growing season, I promise there is plenty of time for a bumper crop.
If you do choose to plant early in the season, you can use row covers to keep the soil and plants warmer than the outside air. Without such protection, early fruits can have pitted skin or other chilling injuries that can make them taste bitter.
Location, location, location. Zucchinis need to be planted in an area that receives full sun, meaning 6 or more hours of direct sun each day.
Southern exposure is ideal for most sun-loving vegetables where they receive light during the majority of the day but are protected from the strongest afternoon sun. Zucchinis can also tolerate a western exposure where the majority of sunlight starts after noon.
Anything less than 6 hours of direct sun is considered partial shade. If you plant your zucchinis in an area with this level of sun exposure, they will not grow as well or produce the amount of fruit you’d expect.
Zucchinis are heavy feeders and require an organically rich, fertile, well draining soil to thrive. If you are using raised beds or containers, choose a well-draining potting soil and add organic material at the time of planting.
If you’re planting seeds directly in the ground, you will likely need to amend your soil ahead of time. Make sure you aerate the soil around and under your planting site (this will prevent soil compaction) and amend it with rich organic material or compost.
Good drainage is also very important to zucchini plants. They prefer moist soil, but don’t want to sit in soaking wet conditions. If you struggle with heavy clay soil like I do, you may need to add amendments that improve drainage. Coconut coir is an excellent choice for this since it improves airflow even when wet, lightens heavy clay, and aids in moisture retention.
Practice Crop Rotation
Even in a home garden, crop rotation is important. This can help reduce soil-borne zucchini diseases from attacking plants year after year. This is especially important if you have dealt with disease in the past.
Ideally, you should avoid planting zucchini plants or other summer squash in soil that was used to grow other cucurbits (the gourd family) for 1-2 years. You can plant other types of vegetables there and relocate your zucchini.
Zucchini – like all summer squash and some melons – do really well when planted on hills. Hills are nothing more than a raised mound of soil, but this small change in elevation can do some great things for your growing plants.
Mounded hills will be slightly warmer than the surrounding soil. This will help your zucchini seeds germinate quicker and also allow you to plant a tiny bit earlier in the season if you want. These hills also allow for better drainage and air circulation since the soil is much looser and less compact than soil in the ground. All of this can maximize the growing environment of our zucchini plants.
You can also plant 2-3 zucchini plants on a hill. This close proximity will go a long way toward helping natural pollination and maximizing fruit production as the season progresses.
Give Them Room
Spacing is important when growing zucchini and all vegetables in general. Zucchini plants, in particular, have very large leaves and can take up a considerable amount of space. Providing enough space between plants and other vegetables, allows them to develop fully and lowers the risk of disease.
Zucchini plants are also heavy feeders (they need a lot of water and nutrients). If you space them too closely together, roots will have a hard time bringing enough nutrients to the plants.
If you are planting in hills, a general rule of thumb is to plant 3 zucchinis per hill (spaced in a triangle pattern) and space hills 3’-4’ apart. Spacing can vary greatly depending on the variety you choose and whether it is vining or bushing. Make sure to check the planting instructions on the back of the seed pack for variety-specific information.
If you are growing in containers, mound the hill in the center of the container and plant 3 zucchinis around it in a triangle pattern.
Provide Proper Support
Did you know you can train any type of zucchini plant to grow vertically? You can! Staking your zucchini plants (even non vining varieties) can save space in your garden, prevent soil-borne diseases, increase air circulation, and reduce pest pressures.
The time to add a stake or trellis is right after planting your zucchini (or after seeds have sprouted). This will prevent your stake, cage, or trellis from interfering with root growth. Place it about 2 inches away from the stem, giving the plant plenty of room to grow.
Loosely tie the stem of the plant to the stake when it’s about 6 inches tall. You can use string or repurpose tomato ties. This will train the plant to grow straight rather than fall down into the dirt. As the plant grows, continue to add ties to higher parts of the stem.
Tomato cages can be very beneficial for zucchinis if you have extra. The added supports will help hold the weight of heavy fruit laden branches as the plant matures.
A lot of garden plants are self-pollinating, meaning that the flowers have both male and female parts. Tomatoes and peppers are great examples of this. Zucchinis, on the other hand, have distinctly male and female flowers.
For the plant to set fruit, a pollinator has to take pollen from the male flower and place it inside a female flower. The fruit then develops from the female flower (the male flower will close and fall off after a few days).
Zucchini plants tend to produce a LOT of male flowers days before the first female flower appears. This happens by design. The large flowers are meant to attract a lot of pollinators so they are already in the area once the first female flowers open up. Unfortunately, the abundance of flowers without fruit can sometimes lead the home gardener to fear there is a problem when there really isn’t.
Pro Tip. Male and female flowers are easy to tell apart. Male flowers have a straight thin stem just behind the flower petals. You can see a load of pollen inside when the flower is open. Female flowers, on the other hand, have a tiny undeveloped fruit that sits just behind the petals.
When You Need to Hand Pollinate
If you’ve noticed female flowers that are not setting fruit, you may need to consider hand pollination. Zucchini flowers open in the morning and close before the heat of the day.
To hand pollinate, find an open male flower, dip a clean paint brush into the center, and coat it with pollen. Move to an open female flower and gently tap the pollen into the center. You can gently rub the brush against the stigma as well to maximize pollen coverage. But be gentle. Repeat this process for all female flowers that are open.
That’s it! You should see the closed female flowers start to swell and grow into a small fruit over the next couple of days.
Remember that you don’t need to let those male flowers go to waste. Fried squash blossoms are one of the best things about late spring and early summer!
If you like to eat a lot of zucchini, plan to preserve or pickle it, and want to have a lot left over to share with friends, consider succession planting! I just a little, but most people feel that they have more than enough with just a few plants. But if you’re like me and can’t get enough, consider succession planting.
Succession planting is simply planting vegetables a few weeks apart so you have a continuous harvest throughout the season. I do this a lot with salad greens, but I’ve also done it with summer squash. Simply plant your first hill early in the season, wait 3-4 weeks to plant the next hill, and another 3-4 weeks for the next. You can continue this process throughout the growing season until your first frost.
Pro Tip. Plan your second planting in mid-July or early August to avoid any issues from squash vine borers. Your plants will also grow more quickly than those sowed in the spring.
Monitor For Squash Borers
Found throughout the eastern US, squash vine borers love zucchini and are the bane of our existence when trying to grow early season squash plants. Adult moths overwinter in the soil and emerge in early summer (late June to early July) to lay their eggs at the base of your zucchini plants.
When the eggs hatch, the larvae burrow into the stem and begin to do their damage. As the pests suck sap and chew up the stem, it cuts off the flow of water to the rest of the plant and can quickly kill it. If you catch the problem early enough, you may be able to save the plant. Here is what to look for.
Monitor For These Signs
- Eggs. The eggs are tiny, flat, oval, and brown. They’re very difficult to see against dirt and mulch, but you may find them clustered together if you get close.
- Larvae.You’ll only ever see the larvae if you slit open the base of your zucchini stem. If the plant is infested, you’ll see the inch long fat, white body destroying your plant.
- Adult Moth. The adult looks a bit like a wasp, but is really a moth. If you see these in your garden at all, take immediate action.
Damage from squash borers are very distinctive. Once you see it, you’ll always know what you’re looking at. First, your plant will appear heavily wilted although it looked healthy in previous days. This is because water is no longer reaching the leaves.
But the most distinctive indication of infestation is an orange-yellow “frass”. This looks a bit like sticky sawdust and is the remains of the chewed up stem left behind by the vine borer larvae.
Squash Borer Prevention
The very best way to avoid vine borers from killing your zucchini plants is to wait and plant until after mid-July. When the adult moths come out of the soil, they’ll move on to other areas since there is no convenient squash plant to lay their eggs by. You can then sow your seeds directly or transplant young seedlings with confidence that they will be free from this particular pest.
If you’re set on an early season crop, though, there are a few things you can do to protect your plant. First is to not plant your zucchinis in an area where other cucurbits (gourd family) were planted previously.
Just like with fungal disease prevention, this will ensure your plants are in a different area from the overwintering squash borers. You can also place a ‘shield’ of aluminum foil around the stem of your zucchini (be sure to dig it under the soil line). This can make it difficult for young larvae to chew their way into the stem.
Zucchini fruits have a fairly high water content, so it is no wonder that zucchini plants are pretty thirsty. A general rule of thumb is to give the plants about an inch of water every week.
If they are in containers or small raised beds, plants will need to be watered more frequently than if they are planted directly in the ground. The best way to determine if your zucchini plant needs water is to stick your finger in the dirt about 2-3 inches. If the soil is dry, it’s time to water. If it’s still moist, give it another day.
During hot weather, you’ll notice that the leaves of your zucchini will wilt in the afternoon. This is 100% normal and does not mean that the plant needs more water.
The leaves should perk up again once temperatures begin to cool in the evening. If the leaves are still wilted in the morning, it’s definitely time to water!
Important Watering Tips
Water slowly and deeply. Most plants don’t like a deluge of water and zucchinis are no different. Think about the difference between taking a nice sip of water from a glass vs someone opening a fire hydrant for you. In an ideal situation, you can set up a drip system before planting.
This will deliver water to your plants in a consistent and manageable way. If you don’t have a drip installed, don’t worry. You can simply turn your hose on the lowest setting and just let it slowly stream into the soil. It may take a little longer than you want it to, but you’ll be happy about the end results.
Water the roots, not the leaves. A common mistake with new gardeners is to water the top of the plant rather than the soil underneath. This can actually cause a lot of problems with your zucchini including the spread of fungal disease (caused from wet soil splashing on the underside of the lower leaves), powdery mildew, leaf burn, and attracting pests.
Always aim to slowly water the soil either with a drip system or low flow hose. Add mulch to the base of your plant to maximize water retention, keep your soil at a consistent temperature, and minimize water splash back.
**Remember to always water your zucchinis in the morning and not during the heat of the day!
Mulch is incredibly important in your garden. It’s especially important in and around zucchini plants. Mulch provides protection against excessive heat, helps soil retain moisture, prevents water splash back (which can spread fungal disease), and discourages weeds.
You can use a lot of organic materials as mulch. Straw, grass clippings, wood chips, and crushed up leaves are all things you can repurpose from your yard (if it hasn’t been treated with herbicide/pesticide).
Keeping your garden clear from weeds can seem like a never ending task. The good news is that you can companion plant certain flowers and herbs with your zucchinis to take some of the work off your plate. Trailing nasturtiums, marigolds, chives, and basil all make excellent weed barriers around your zucchinis and have the added benefit of pest control as well!
Mulch will also have the added benefit of weed control in your garden. Anything you can do early in the season to make gardening in the heat of summer is a win!
Companion Plant Your Zucchini
Companion planting is one of my favorite things to write about. I think I have probably mentioned it in almost every article that I’ve written! I do this because it’s so important to an organic garden. Certain plants can deter pests, attract pollinators and predatory insects, stimulate growth, and even improve flavor.
Here are some great examples of herbs, veggies, and flowers to companion plant with zucchini.
Beans, Corn, and Squash
Zucchini is one of the three sister vegetables – beans, corn, and squash. This trio was typically planted together in indigenous peoples’ gardens and farms because of the very real benefits the vegetables brought each other.
Indigenous peoples also believed that the grouping was a “gift from the gods” and that they should be planted, eaten, and cherished together. It’s really quite beautiful.
The practical value of companion planting these three vegetables is undisputed. Beans (peas will do the same thing here) pull nitrogen from the air and add it back into the soil.
This directly benefits the other plants – especially heavy feeding zucchini – by providing them with vital nutrients. Corn provides a structure for vining beans to grow up, and the large leaves of squash plants provide natural ground cover that deters weeds. This truly is a top notch match that is the perfect example of what companion planting can do for your garden.
Most fragrant herbs – peppermint, dill, oregano, parsley – help deter pests from your zucchini plants. It’s helpful to choose only one or two of these, however, since the flavor of the herbs can be altered if too many different varieties are planted close together.
Here are some of my favorite herbs to plant near zucchini.
This is one of my all time favorites although it’s not often found at local nurseries (I have to order seeds). Borage is a flowering herb that pollinators and predatory insects swarm to. This will go a long way toward both natural pest control and natural pollination once your zucchini flowers start to bloom.
A strong smelling herb that repels pests like cucumber and flea beetles. Dill is a great herb to grow in your garden if you plan to make pickles this year!
Another one of my favorites, the sulfur compounds deter aphids and come back year after year. These are also great to add to your cooking wherever a light onion flavor is needed.
If you have issues with deer eating your zucchini flowers, mint can help deter them. Some mint plants like hyssop and sage have a smell that deer really don’t like. Try planting mint around the edges of your garden, but be careful since mint can take over a large space very quickly.
Flowers are incredibly important to encourage pollinators to check out your zucchini plants. Planting flowers natural to your area can really help this as well. But if you’re looking for some tried and true flower helpers, check out marigolds and nasturtiums.
French marigolds especially act as a trap plant and will attract pests like whiteflies, aphids, and squash bugs away from your zucchinis. You’ll need to plant these several weeks ahead of your zucchini for them to be large enough to make a difference. Plant them far enough away from your zucchini so the pests can’t easily migrate over.
Nasturtiums attract pollinators, predatory insects, and act as a trap plant specifically for aphids. When planted near your zucchini, they can also help enhance the vegetable’s flavor, vigor, and growth rate.
Avoid Plant Competition
While some plants are excellent companions for zucchini, there are a few you should avoid planting nearby.
Potatoes are very heavy feeders and can compete for nutrients with your zucchini plants. I actually prefer to grow potatoes in grow bags that are kept separate from the rest of the garden. This allows you to fertilize them appropriately, and it also makes harvesting a breeze.
Based on the fact that fennel is quite fragrant, you would think it would make a great companion plant. While it does deter some pests and attracts other beneficial insects, it can actually impede the growth of your zucchini.
Avoid planting any other gourd – pumpkins, melons, winter squash – near your zucchini and summer squash. Fruit production can be seriously impacted due to issues with cross pollination.
It’s now time to enjoy the fruits (literally!) of your labor. The amazing thing about zucchini is that you will continue to harvest fruit for quite some time. Get ready!
Ideally, aim to harvest your zucchinis when they are about 6-8” long. If you leave the fruit on longer than that, both the seeds and the rind will harden and make it inedible. Use a pair of sharp sheers and cut the fruit off directly at the stem.
Don’t try to pull the fruit off like you would a tomato. This will damage the plant. Make sure you look under all those big leaves and look for fruit that may be hiding. I have certainly discovered more than one jumbo sized zucchini that I just wasn’t able to see!
**Pro Tip. If you do find hidden jumbo zucchinis, you can either compost them or give them to a friend with chickens or other livestock, or even a petting zoo! Oversized zucchinis make great feed for animals.
Once harvested, you can use zucchini in a number of cooking applications from stir fry to soups to casseroles to a lovely side dish. I also shred and freeze quite a bit of my zucchini harvest to use in squash breads, muffins, and fritters throughout the year.
Now that you know how to keep your zucchini plant happy, pollinated, and safe from squash bugs, it’s time to enjoy the process. Zucchini can be an extremely rewarding garden plant, as long as it’s properly cared for. They grow quickly, and are one of the top garden plants for veggie gardeners that have thin patience levels! Now it’s time to enjoy all the zucchini you are about to harvest!