Zucchini is a versatile and popular summer squash that is easy to grow in Australia. It’s perfect for gardeners of all skill levels, as it requires minimal maintenance and can produce a large yield.
The mild flavour of zucchini makes it great in many recipes, from savoury to sweet. If you want to start growing your own vegetables, zucchini is a great place to begin.
When to Plant Zucchini in Australia
Zucchini is a sun-loving plant that thrives in warm weather. The ideal time to plant zucchinis in Australia is spring or early summer, typically between September and December.
Remember, these timings can vary based on your location and local climate. So, it’s always a good idea to consult with your local gardening centre or nursery to pinpoint the perfect planting time.
Soil Preparation for Planting Zucchini
The secret to growing a healthy zucchini plant lies in the preparation of the soil of your vegetable garden.
Zucchini plants need well-drained soil rich in organic matter. Dig in some well-rotted compost or manure a couple of weeks before planting.
Zucchini prefers a slightly acidic to neutral soil pH, around 6.0–7.0. If you’re unsure about your soil’s pH, consider testing it.
What You Need to Start Growing Zucchini
Starting a zucchini garden is a fun and rewarding venture.
Here’s a handy list of what you’ll need to get started:
- Zucchini seedlings or seeds: You can start your zucchini garden from seeds or buy seedlings from a nursery or garden centre.
- A sunny spot: Zucchini plants love the sun, so choose a place in your garden with plenty of sunlight.
- Well-draining soil: Your zucchini plant needs soil that drains well. You might need to amend heavy clay soil with compost or other organic matter to improve drainage.
- Compost or manure: Zucchinis prefer rich, fertile soil. Adding well-rotted compost or manure to your garden bed before planting can greatly boost soil fertility.
- Vegetable fertiliser: A balanced vegetable fertiliser will provide the nutrients your zucchini plants need to produce a healthy crop. Look for one that’s specifically formulated for vegetables.
- Mulch: Mulching around your zucchini plants can help conserve water, suppress weeds, and keep the soil temperature steady.
- Garden tools: You’ll need some basic gardening tools, like a trowel for planting seedlings, a hoe or rake for preparing the garden bed, and a watering can or hose with a gentle spray nozzle for watering your plants.
- Gardening gloves: Protect your hands from dirt and potential skin irritants by wearing a sturdy pair of gardening gloves.
- Stakes or a trellis (optional): Zucchini plants can spread out quite a bit. If space is a concern, consider growing them vertically using stakes or a trellis.
How to Grow Zucchini from Seeds
Growing zucchini from seeds is a rewarding and cost-effective way to enjoy this versatile vegetable.
Here’s a step-by-step guide on how to do it.
Step 1: Choosing your seeds
There are many varieties of zucchini to choose from, so pick the one that suits your taste and climate.
Step 2: Selecting a spot
Zucchinis love the sun, so pick a place in your vegetable garden that gets plenty of sunlight.
They also need well-drained soil and lots of space to spread out, so consider that when planning your garden.
Step 3: Planting your zucchini seeds
Once the danger of frost has passed and the soil has warmed up to at least 15–20°C (usually between September and December in Australia), it’s time to plant your seeds.
Sow seeds about 2.5cm deep and around 60–90cm apart, as zucchini plants need room to grow.
Step 4: Watering
Zucchini plants require regular watering. After planting, water your seeds thoroughly but gently.
As your plants grow, aim to water them deeply and regularly, especially during dry spells.
Try to water at the base of the plants to avoid getting the leaves wet, as this can lead to fungal diseases.
Step 5: Fertilising
Feed your zucchini plants with a balanced vegetable fertiliser every 2–4 weeks to encourage healthy growth and a plentiful harvest.
Step 6: Thinning seedlings
If you planted more than one seed in each hole, you might need to thin out the seedlings once they’re a few inches tall.
Keep the strongest seedling in each spot and carefully remove the others.
Step 7: Harvesting
You can start harvesting your zucchinis when they’re about 15–20cm long. Don’t be afraid to harvest frequently, as this can stimulate the plant to produce more fruit.
Remember, growing zucchini from seeds requires patience and regular care, but the result is worth the effort.
In a few months, you’ll enjoy fresh, home-grown zucchini from your garden.
How to Grow Zucchini Vertically
If you’re a fan of small-space gardening, growing zucchini vertically is the way to go.
You’ll need a trellis or stakes for this planting style.
Prepare to Grow Zucchini Vertically
Now that you know the benefits of growing zucchini vertically, it’s time to start.
- Pick a location that has at least six hours of sunlight each day. This could be a patio or balcony with ample sunlight.
- Choose a large container to support the zucchini plant’s root system or a sturdy trellis to support the plant’s weight.
- Use high-quality soil rich in organic matter to promote healthy plant growth. Opt for a fertiliser that is formulated for vegetables.
- Pick a zucchini variety that is suitable for container or trellis growing. Some good varieties to consider include ‘Black Beauty,’ ‘Costata Romanesco,’ and ‘Gold Rush.’
Vertical Planting and Care for Zucchini Plants
Plant zucchini seeds according to the package instructions or transplant seedlings into the container or trellis.
- Water the plants regularly. Zucchini plants need at least 2–3cm of water per week. Make sure the soil is moist but not waterlogged.
- Provide support when needed. As the plant grows, tie it to the trellis or support system to help it grow upright.
How to Grow Zucchini in Pots
Zucchini is a versatile fruit that can be eaten fresh, cooked, or even turned into baked goods.
It’s easy to grow and can thrive in almost any setting, including pots.
Step 1: Choose a suitable container
The first step for growing zucchini in pots is selecting a suitable pot. You’ll need at least an 18L pot to accommodate the plant’s roots.
Make sure that the pot has drainage holes to prevent waterlogging and root rot.
If you plan to keep the container on a balcony or patio, consider its weight, as a large pot filled with soil can be challenging to move around.
Step 2: Pick the right soil
Zucchini loves fertile, well-draining soil with a slightly acidic pH of 6.0–7.0. Avoid using heavy garden soil, which is too dense and retains too much water.
Instead, use a high-quality potting mix that contains organic matter such as peat moss, compost, or coco coir. You can also add some perlite or sand to increase the drainage and aeration of the soil.
Step 3: Sow seeds into the pot
Plant zucchini seeds directly in the soil or start them indoors and transplant them outside later. Follow the instructions on the seed packet or the plant label.
Ideally, there should only be one zucchini plant per pot, as these dark green vines grow large.
Step 4: Place the container in a sunny spot
Zucchini requires at least 6 hours of direct sunlight per day to thrive. Find a spot on your balcony, patio or rooftop that receives ample sunlight throughout the day.
If you live in a hot region, consider placing the pot in a partially shaded area, as excessive heat can cause the zucchini leaves to wilt and dry out.
Step 5: Water often
Container plants need more frequent watering than those grown in the ground since the soil in a pot dries out faster.
Water your zucchini plant thoroughly and evenly once a week, depending on the weather and humidity levels.
Try not to overwater the plant, as this can lead to root rot. You can stick a finger into the soil to check its moisture level before each watering.
Step 6: Harvest the zucchini regularly
The ultimate reward of growing zucchini in pots is harvesting fresh, homegrown vegetables! Zucchini plants can produce fruit in just a few weeks from planting.
Once you see small zucchinis forming, watch them closely and harvest them when they reach a length of 15–20cm.
If you leave them to grow beyond this point, they may become woody and inedible.
How to Grow Zucchini from Scraps
Whether you have leftover zucchini ends or want to experiment with your gardening skills, we’ll show you how to turn scraps into thriving zucchini plants in just a few simple steps.
Step 1: Save your zucchini scraps
The next time you use zucchini in your kitchen, save the end of the vegetable where the stem was originally attached. Try to keep about 5 cm of the vegetable with the stem end.
Step 2: Preparing the scraps
Take a toothpick or a small skewer and insert it crossways into the zucchini scrap about halfway up.
You will be suspending this piece over water, and the toothpick or skewer will hold it in place.
Step 3: Submerge in water
Next, you’ll need a shallow dish or jar filled with water.
Place the zucchini end over the container to submerge the bottom half. The toothpicks will keep it from sinking to the bottom.
Step 4: Wait for rooting
Put the dish or jar in a sunny spot and change the water every few days to keep it fresh.
With patience and luck, roots will begin to sprout from the zucchini scrap in 1–2 weeks.
Step 5: Planting
Once you’ve got a nice set of roots, it’s time to plant your zucchini scrap.
Choose a spot in your garden with rich, well-drained soil and plenty of sun. Bury the zucchini scrap so that the surface is just level with the soil.
Step 6: Care for your plant
From this point on, treat your zucchini scrap like you would any zucchini plant. Water it regularly, fertilise it every 2–4 weeks with a vegetable fertiliser, and watch out for any pests or diseases.
As your plants grow, you may need to transplant them to larger containers or your garden bed, depending on the size of your scraps and available space.
When to Harvest Zucchini
The best time to harvest zucchinis is when they are young, tender, and about 15–20cm long.
Harvesting zucchinis regularly is important because they can grow rapidly, and if left too long, they can become tough and inedible.
Use a sharp knife or pruning shears to cut the zucchini from the plant. Cut the zucchini at the stem, starting from the base of the fruit, with clippers or a sharp knife.
How to Fertilise and Prune Zucchinis
Zucchini plants require regular fertilisation. You can use synthetic or organic fertilisers high in nitrogen, potassium, and phosphorus.
When the plant starts to develop flowers, switch to a fertiliser high in potassium and phosphorus.
Pruning is also recommended to encourage the plant to spread out, get more sun, and produce supportable fruit.
Understanding Zucchini Pollination
Zucchini plants are monoecious, meaning they produce both male and female flowers on the same plant.
The male flowers usually appear first, followed by the female flowers. You can identify the female flowers by the small, immature fruit at their base.
If you want to increase your zucchini yield, you’ll need to pollinate your zucchini plants.
Pollen is usually transferred from the male to the female flower by bees or other pollinators.
If this type of zucchini pollination is ineffective, the female flowers will wither and drop off without producing any fruit.
Zucchini Companion Plants
Zucchini plants are large and leafy and appreciate a bit of extra space. However, there are several plants they partner well with in the garden.
Here are some of the best companions for your zucchini:
- Corn: Corn and zucchini are great companions. The tall cornstalks provide some much-needed shade for zucchini during the heat of the summer, and in return, zucchini’s broad leaves suppress weeds that might otherwise compete with the corn.
- Beans: Beans are another good companion plant for zucchini. They help to fix nitrogen in the soil, which zucchini will appreciate since they are heavy feeders. Plus, beans grow vertically, saving space and reducing competition.
- Nasturtiums and Marigolds: Both nasturtiums and marigolds are beneficial because they deter common pests. Nasturtiums repel various pests, including aphids and squash bugs, while marigolds are known for repelling nematodes.
- Peas: Like beans, peas fix nitrogen in the soil and grow vertically, making them a good companion for zucchini.
- Radish: Planting radishes near your zucchini may help deter squash borers, a common pest for zucchini and squash plants.
- Mint: Mint can help deter pests that are attracted to zucchini. However, be aware that mint is a vigorous spreader and should be planted in a pot or container to prevent it from taking over your garden.
Plants to avoid planting with zucchini
Just like there are good companions, there are also plants that don’t get along well with zucchini.
These include potatoes, which compete for nutrients and can increase the risk of blight and other diseases.
It’s also recommended to avoid planting zucchini near other squash or pumpkin plants to prevent cross-pollination.
Common Pests and Diseases Affecting Zucchini Plants
Zucchinis are susceptible to pests, such as squash bugs and powdery mildew. Inspect your plants regularly and treat any affected plants promptly.
Squash bugs are the most common pests that plague zucchini plants.
They are tiny and flat, with brown or grey bodies that measure about 2cm long. Squash bugs suck the sap from your plant, damaging the leaves and eventually causing the plant to wilt and die.
You can spot them on the leaves undersides and around the plant’s base. Start by hand-picking them from your plants to get rid of squash bugs.
You can also spray a mixture of water and soap to eliminate them. For more severe infestations, use insecticide.
Squash vine borers
The squash vine borer is a type of moth whose larvae bore into the base of the plant stem. This can cause a wilting or collapse of the plant.
To avoid squash vine borers, plant resistant varieties of zucchini in well-drained soil.
You can also cover your plants with floating row covers early in the growing season to prevent the moth from laying eggs on them.
Blossom end rot
Blossom end rot is a common disease that affects zucchini plants during fruit development. It is characterised by black or brown rot spots on the end of the fruit.
Blossom end rot is often caused by a calcium deficiency in the soil or inconsistent watering.
You can combat this disease by ensuring that your soil is rich in calcium by adding eggshells, lime, or gypsum.
Water your plants regularly and consistently to prevent the soil from becoming too dry or too wet.
Powdery mildew is a fungal disease that forms a white powdery coating on the leaves of plants.
If not addressed, powdery mildew can weaken the plant, decrease yield, and reduce the overall quality of your zucchinis.
To prevent powdery mildew, avoid overcrowding your zucchini plants, as the lack of air circulation can cause the disease to spread.
You can also use organic neem oil or milk sprays to keep powdery mildew at bay.
Cucumber beetles are another pest that can cause damage to zucchini plants. These pests can cause leaves to wilt and turn yellow or brown and feed on the fruits, making them unappetising to eat.
Look out for shiny green or yellow beetles that have black stripes on their backs.
To prevent an infestation, use row covers and plant trap crops such as mustard or radish nearby to deter the beetles from your zucchini plants.
How do I get my zucchini to produce fruits?
Getting your zucchini plants to produce fruit can sometimes be challenging, particularly if you’re new to gardening.
Here are a few tips that might help:
- Pollination: If your zucchini plant has flowers but no fruit, it might be due to insufficient pollination. If you don’t have many pollinating insects around, you can manually pollinate by using a small brush or cotton swab to transfer pollen from the male flowers to the female ones.
- Proper watering: Zucchini plants require regular, deep watering. Inadequate water can result in poor fruit set and small, misshapen fruit. However, try to avoid wetting the leaves when you water, as this can lead to fungal diseases.
- Fertilisation: Zucchini plants are heavy feeders, requiring lots of nutrients. Use a balanced vegetable fertiliser to ensure your plants get all the nutrients they need to produce fruit.
- Proper spacing: Zucchinis need plenty of space to grow and produce fruit. If the plants are crowded, they may produce less fruit. Ensure that your plants are spaced according to the recommendations for the specific variety you’re growing.
- Disease and pest control: Diseases and pests can affect your plant’s health and ability to produce fruit. Regularly check your plants for signs of disease or pest infestations, and treat any problems as soon as you spot them.
- Sunlight: Zucchini plants need lots of sun to produce fruit — ideally 6–8 hours daily. If your plants are shaded, they might not produce as much fruit.
How long does it take to grow a zucchini?
From the day of planting, you can expect to harvest your first zucchini in approximately 45 to 55 days when grown from seed.
This timeframe might be shorter if you start from seedlings or transplants, usually around 35 to 40 days.
Zucchini plants continue to produce fruit throughout the growing season until the first frost.
To ensure a steady yield, it’s recommended to harvest zucchini when they’re about 15–20cm long. Regular picking encourages the plant to produce more fruit.
Grow a Bouquet of Zucchini Flowers
Zucchini is a fast-growing vegetable and one of the most rewarding plants for a home gardener due to its high yield and quick maturity.
You can have a bumper crop of healthy and delicious zucchini with the right location, soil preparation, and regular care.
Plus, you’ll know exactly what you’re putting in your body since they’re homegrown. And if you ever need help to maintain your garden, call a professional gardener!