Organic Container Gardening: Growing Zucchini (Courgettes) in Pots
Zucchini (or courgettes as they are known here in Europe) are fast growing, productive and robust, making them one of the easiest vegetables to grow. They are a perfect choice for beginner gardeners.
You Will Need:
- Organic zucchini seed
- Small containers for seedlings
- Large containers for adult plants (five gallons minimum—the bigger the better!)
- Some high-quality organic potting compost
- A sheltered sunny spot (If you live in a cold climate then you can grow them in greenhouses. It's best not to plant them outdoors until all chances of frost have passed.)
- Organic fertilizer
- Straw mulch
- Trellis or bamboo poles (optional)
Growing Zucchini From Seed
The best way to get organic zucchini seed is to buy it from a reputable garden centre or online store. You can also get seeds from the zucchini squash itself, but it has to be a very mature large one—they are usually harvested while still small before the seeds have developed, so it's easier to buy the seeds in packets.
Before sowing the seeds, I find it helps to soak them in room-temperature water overnight. This seems to make them germinate faster.
Sow the seeds in small pots by making a small hole one inch deep and pressing the seed into it on its side. Cover and water gently, keeping them moist until they sprout in approximately seven days.
The first two leaves to appear are not true leaves; these are called cotyledons. Once the seedlings have grown at least two "true" adult leaves, they will be big enough to be hardened off and planted in larger containers outside. Depending on the climate you live in, they can be grown directly outdoors or in a greenhouse. If you don't have space outdoors, you can grow them indoors by a sunny windowsill too—but be warned, zucchini plants get BIG!
Transferring Seedlings Outdoors
"Hardening off" means preparing the seedlings for outdoor life. Seedlings are pretty weak and delicate, so it takes them time to adjust to the great outdoors. The trick is to help them adjust little by little. Put the seedlings out for one or two hours for the first couple of days, in the shade. Then one hour per day in direct sun gradually increasing the time per day, but don't overdo it too soon or they may wither.
Once they start to adjust, the leaves will turn a darker green, and they will be ready to leave outdoors all the time.
Bear in mind that they will probably need more watering once outside, especially in a hot sunny climate (perfect for zucchini growing). Container plants always need watering more often than plants in the ground. This is where mulching comes in—using a mulch can help to keep a plant healthy and hydrated during hot weather, so be sure to cover the top of the soil with straw mulch or a good alternative.
In addition to plenty of watering, start to fertilize the plants with an organic fertilizer every two weeks or so.
The whole point of organic gardening is to avoid pesticides or genetically modified seeds that produce these poisons internally.
Pests can be a big problem for organic gardeners. Apart from handpicking bugs and caterpillars off the plants or strategically placing plants that are natural deterrents close by, there are a few other methods you can try:
- Insect warfare—ladybirds, wasps, spiders—all good for getting rid of the pests on your plants!
- Soapy water—spraying leaves with mild soapy water is usually enough to deter aphids and other leaf pests
- Diatomaceous earth—effective for preventing vine borers, slugs
- BT—supposedly a natural protein, it kills all kinds of caterpillars without harming other insect life (such as bees which are often harmed by pesticides). It can be found in most garden centres. I prefer not to use BT unless I really have to though.
Growing Zucchini on a Trellis
Zucchini plants, as I may have mentioned before, grow big. They are trailing vines, so unless you want your plants to spill over the edges of their pots and trail over the ground, it's best to stake or trellis them.
Plants that are growing upright are usually healthier too, because the air can circulate better, which helps to avoid rotting and disease. For containers, the best method I have found is to attach a wire mesh trellis to a wall behind the plant as this ensures the plants are very stable when they grow up it. Feel free to experiment with other methods though, depending on your outdoor space and resources.
Pollinating and Harvesting Zucchini
Zucchini plants start to produce fruit very fast, sometimes as soon as six weeks after planting! The plants will produce male and female flowers, distinguishable by the thickness of their stems. The males have thin stems and the females thick ones, the latter looking like mini zucchini as soon as they grow. The females must be pollinated by the males for the fruit to form properly.
If you find that the zucchini growing on your plants are very small or withered looking and drop off, you may have a problem with pollination. This can be remedied by pollinating the female flowers by hand. How to pollinate by hand? Well, it's simple. Break off a male flower, remove the petals to reveal the pollen covered stamen and rub this on the stigma of the female flower. Voila! If you don't like the idea of breaking off a male flower, you can use a cotton swab to transfer the pollen instead.
When harvesting zucchini, cut them off with a sharp knife. They are best when they are still small; no more than two inches thick. The smaller the better when it comes to flavour!
The flowers are also edible and can be eaten raw in salads or cooked. Try frying them lightly with butter and garlic—there's nothing quite like it.
And now you know all you need to start growing organic zucchini in containers.