Summer squash is one of the easiest vegetables to grow, and it’ll provide you with a constant bumper harvest all summer long. In fact, just two plants will feed an entire family if you follow our tips. Plus, you’ll have some spare to share with your neighbors.
To grow summer squash, you need a large sunny spot in the garden. Plant it in warm soil with plenty of added organic matter and a soil pH of 6 to 6.5. Seeds should be sown around ½ inch deep in slightly raised mounds to allow for good drainage. Water daily when it’s hot but only apply water to the roots.
Here are 11 top tips on how to grow summer squash successfully.
1. Choose Either Bush Or Climbing Varieties
While there are numerous different varieties of summer squash that you can grow, these are grouped into two distinct growth habits. There are bush varieties that are confined to a large bushy plant and climbing varieties that will trail and climb over everything.
Whichever one you choose, you have to allow enough space for each plant to grow. Bush varieties should be grown fairly close together to ensure good pollination. You should plant them no more than two to three feet apart (60 to 90 cm). It doesn’t matter if the individual plants grow into one another as long as it’s still easy to harvest the crop.
For climbing varieties, you’ll need to provide some sort of support for them to climb over. Otherwise, they’ll climb all over your other vegetables and smother them. You can use a trellis but make sure that it’s sturdy because the plants will be quite heavy once they’re fruiting.
2. Plant A Number Of Different Varieties
As mentioned, one or two plants will feed an entire family, but there are so many different varieties to choose from, why only grow one? If you grow a selection of different varieties, you’ll have a continuous bumper crop that will keep your family guessing as to what you’re going to have for dinner each night.
For example, zucchinis such as “Black Beauty” are a bush variety that is very easy to grow. These are ideal for making zucchini fritters, adding to a stir-fry, or making zoodles.
Then, there is button squash in a variety of colors, including white and bright yellow. These are ideal for adding to stews or roasting in the oven with some root vegetables.
Don’t forget Yellow Crookneck squash. This variety is bright yellow and has a curved neck. It keeps well in the fridge and is ideal for adding to stir-fries because it readily absorbs the flavorful spices you’re going to add.
And, if you love stuffed summer squash, try the Lebanese variety. This produces lovely fat fruit that you can slice in half, stuff with whatever you want, and bake in the oven for a quick and delicious mid-week meal.
3. Prepare Your Soil Well Before Planting
Summer squash prefers a soil rich in organic matter, but that is well-drained. You’ll get the best results if you add some aged compost to your soil before planting your seeds or transplants.
Ideally, the soil pH should be between 6 to 6.5, but summer squash is fairly forgiving if you can’t get this exactly right. In fact, these plants can tolerate acidic soils as low as 5.5 pH. As long as you provide them with plenty of water and fertilizer, they’ll reward you with a bumper harvest.
It’s a good idea to create little hills or slightly raised rows for planting your summer squash. This allows for better drainage and means the plants won’t be sitting in water if you get too much rain or forget to turn the drippers off.
Another great way of growing summer squash in the garden is to use a raised bed system. This provides the necessary drainage and makes it easier to harvest the fruit.
Summer squash can also be grown in pots or grow bags. However, make sure you select a fairly large pot to accommodate the spread of the plant. If you want to grow a climbing variety in a pot, you’ll also need to add a trellis or some other type of support for the plant.
If growing in pots, it’s a good idea to have one plant per pot but have two or more pots placed quite close together. This will help with pollination and ensure that your plants produce as much as possible. You might even like to choose two different varieties.
4. Select Whether You Want To Plant Seeds Or Transplants
Whether you choose to start your plants from seeds or transplants is entirely your choice. Remember, though, that growing from seed will take a little longer to produce your first harvestable fruit. It usually takes around 45 to 60 days from the time you plant the seed to when you can harvest your first squash.
This means that seeds should be planted in early spring once the threat of frost is completely gone. This will ensure that you’ll have plenty of summer squash all through the warmer months.
Most seeds should be planted around ½ to 1 inch deep in the soil spaced around two to three feet apart. You should plant at least two to three seeds per hole to ensure that you get good germination. If all three seeds germinate, you might like to thin them out so that you only have two plants on each mound.
Transplants can go into the ground anytime in spring as it won’t take as long for them to start producing. Especially if the weather is warm and the plants get plenty of moisture and fertilizer.
Plant two plants on each mound and then leave a space of around two feet and plant another two plants together. Continue along the row until you’ve planted all the seedlings that you have.
5. Add A Layer Of Mulch Or Cover The Soil With Plastic
Summer squash like warm soil (at least 60 degrees Fahrenheit or 16 degrees Celsius) to thrive and grow happily. You can help your plants stay warm by covering the soil once you’ve planted your seedlings or your seeds have started to germinate. There are two ways that you can cover the soil to keep your plants happy and their roots nice and warm.
- Cover the soil with plastic. If you use any type of plastic, it helps to insulate the soil and keep it warmer. Black plastic is great because it will absorb the heat from the sun and warm up the soil beneath. This also helps to stop the moisture from evaporating too quickly which means less watering for you.
All you need to do is get a length of plastic and cut some holes for the plants to grow through. Carefully place this around your plants, making sure to keep the plastic away from the plant stems. You can also just lay a length of plastic along either side of the row if you don’t want to take the time to cut holes.
- Use a thick layer of mulch. Laying down mulch will not only help to keep the soil warm but it will also hold the moisture in the soil. Clean mulch such as hay, straw or pea mulch is best for this purpose. Just spread a thick layer around the base of your plants, keeping it a little away from the plant stem.
Another benefit of using mulch is that it will eventually break down and add valuable nutrients to the soil.
Apart from keeping the soil warm and helping it to retain moisture, these methods will also help to keep the summer squash fruit clean and stop the soil from washing up onto the plants. This is one way of keeping your plants free from soil-borne diseases too.
6. Choose A Sunny Spot In Your Garden
Summer squash loves the sun and needs at least 6 hours of sunlight a day if you want to have a good harvest. However, if you live in a really hot climate and you find your plants are constantly drooping in the early afternoon, you can provide them with a little afternoon shade during the hottest part of the year.
You can do this easily by setting up a temporary shade structure that will provide shade from the afternoon sun but still allow the plants to get plenty of morning sun.
7. Keep Your Plants Well Watered
Summer squash is a thirsty plant. This means that during the heat of summer, your plants may need watering every day or even twice a day. Of course, this depends on how much rainfall you get as well. Essentially, summer squash plants need around 1 inch of water every week.
But, don’t worry. Squash plants will tell you when they need more water. If you see the leaves starting to droop, it’s a good sign that the plants need to be watered. This can happen even if you think that the soil is still slightly moist.
Primarily, you should water your plants first thing in the morning before the sun has time to get really hot. Then, if it’s been hot during the day, you might need to water your plants again in the late afternoon. Try to avoid watering your summer squash just before nightfall because this can attract fungal diseases if the plants are wet during the night.
When watering, it’s really important to only direct the water to the roots and avoid getting any on the leaves. If the leaves get wet, it leaves them open to attack from a fungal disease called powdery mildew.
The ideal way to water summer squash and many other types of vegetables is with a drip system or a soaker hose. Once you install a good drip system, you can use it again and again, no matter what type of vegetable you’re growing.
All you need is a length of poly pipe, some drip lines, and dripper heads. You can find all of these at your local garden center or hardware store. A drip system is easy to install and can be attached to an outside hose or tap. You can even put a timer on the tap so that you don’t forget to turn it off.
Experienced gardeners quite often use an automatic timer system that you can program to come on and turn off at a specific time during the day. This will ensure that your plants always get the water that they need.
A quality soaker hose is another good alternative for keeping your summer squash plants well-watered. A soaker hose is one that has numerous holes all along its length. All you have to do is lay it around the base of your plants. Then, when you turn on the tap, the water will just seep out of the holes.
If you purchase a good quality one, you’ll be able to use it for many years before weathering will mean it needs to be replaced.
8. Feed Your Plants To Get More Fruit
Summer squash is a heavy feeder. If you’ve added plenty of aged compost to the soil before planting, it should keep the plants growing strongly for a number of weeks.
Once you start seeing flowers, it’s a good idea to apply some liquid fertilizer to your plants on a fortnightly basis. Liquid seaweed is good for this, or use a commercial fertilizer that is well balanced. You want to ensure that there’s plenty of phosphorus and potassium in the fertilizer as well as nitrogen.
You can see the breakdown of what the fertilizer contains as a series of three numbers on the package. For example, 10:10:10 which is an equal balance of nitrogen, phosphorus, and potassium (N:P:K).
The nitrogen will help to keep your plants growing strongly, while the phosphorus and potassium will help with fruit production. If you’re applying liquid fertilizer, be sure to only water it into the roots and avoid getting any onto the leaves.
The best way to do this is to use a watering can with the rose removed. Just mix the fertilizer with water as per the recommended dosage on the pack. Then, just direct the liquid to the base of each plant.
You may also choose to use a granular fertilizer. Once again, make sure it’s balanced and scattered on top of the soil around the base of the plants. Then, water in well to ensure that the fertilizer gets down to the roots. Try to avoid getting any granules on the plants themselves. If you happen to accidentally get some on the plants, just wash it off quickly. Otherwise, it may burn the leaves or the stem.
9. Ensure Adequate Pollination
Summer squash plants have both male and female flowers. The male flowers are usually larger and appear first. These are followed by the female flowers that will have a little swelling at the base. This is the beginning of the squash fruit.
In order for your plants to produce plenty of fruit, pollination needs to occur. That is, the pollen from the male flowers has to be deposited onto the pistil of the female flower. Usually, pollinators like bees take care of this task for you, and you don’t have to do anything.
However, if there are not enough bees in your garden, you might need to do some hand pollinating to ensure plenty of fruit set. Try to do this early in the morning. Here’s what to do:
- Take the male flower and rub the pollen laden stamen onto the pistil in the female flower. Once you take a closer look at the flowers, you’ll know what the stamen and pistils look like. They’re the internal parts of the flowers.
- You can also use a cotton swab or small paintbrush to transfer the pollen from the male flowers onto the female ones. It’s very easy to do.
Remember, you only have to do this if there are not enough pollinating insects in your yard. This can be determined when you notice that the small fruits behind the female flowers don’t grow and just wither and die.
The best thing to do to avoid having to hand pollinate is to encourage bees and other pollinators to your garden. You can do this by planting a few different flowers around your vegetable plot.
Consider a lavender bush or two or even some lovely flowering herbs like thyme, rosemary, chives, or oregano. You can even grow a border of flowers around your veggies. Consider nasturtiums and marigolds as bees love these.
10. Harvest Often To Encourage More Fruiting
Fruits like summer squash need to be harvested often to encourage more of them to grow. These also have a nicer flavor when they’re picked while still young and not too large.
It’s important to check your fruits daily as they grow very quickly and can double in size overnight. Fruits like zucchini and straightnecks should be harvested when they’re a few inches long. At this stage, they’ll taste great and will be nice and tender.
Make sure that you harvest all the fruit off the plant once they get to this size and don’t leave any behind. If the fruits are left on the plant for too long, they’ll eventually give off a hormone that will make the entire plant shrivel up and die.
If you can’t use all the fruits as you pick them, you can give them away to family, friends, or neighbors. It’s also better to throw any excess into the compost if you can’t give them away rather than leave them on the plant to reach full maturity.
But, why not get creative and find different ways you can use these delicious fruits in your cooking. And, don’t just think about savory meals either. Bake some zucchini bread or muffins with added chocolate chips. This is a great way to get your kids to eat more vegetables.
11. Check Daily For Pests And Diseases
For experienced gardeners, it’s no secret that summer squash plants are prone to the fungal disease called powdery mildew. You can spot this as white, powdery-looking patches that first appear on the undersides of the leaves.
If you spot this disease early, there are things you can do to protect your plants, as a heavy infestation will halt fruit production. Here’s what to do if you spot powdery mildew on your squash plants:
- Remove all infected leaves and dispose of them in the garbage bin. Don’t put these into your compost.
- Spray all your plants with either a homemade solution of baking soda and water or a mix of milk and water. The milk spray has proven to be quite successful in halting the spread of the disease. Alternatively, you can spray your plants with a commercially available sulphur spray or a solution of neem oil and water.
- Re-apply the spray at least once a week until you see no more evidence of powdery mildew.
- Any heavily infested plants should be removed altogether and placed in the garbage because these will not produce many more fruits.
The most common pests affecting summer squash are squash bugs. These bugs attack the leaves and cause them to blacken, wither and become brittle and die. The bugs are brown to black in color. If your plants have been affected by squash bugs, you’ll see brown, dead patches on the leaves.
To control squash bugs, look on the underside of the leaves for eggs and remove them. Adult bugs can also be removed by hand to avoid further damage.
Other common insects you might find on your squash plants include aphids and whiteflies. You can control these by spraying the plant with insecticidal soap. For good whiteflies control, you can also get sticky paper traps that you hang around your plants.
Growing summer squash is easy and will reward you with a bumper crop of delicious fruits that will feed your family all summer long. You might even find that you have an abundant harvest that you can share with family and friends.