What NOT to Plant in October

October is one of those months when the veggie garden suddenly feels as though everything should be planted. The days are longer, the soil is warming up, seedlings are everywhere in the nurseries, and summer is just around the corner. But just because you can find a seedling doesn’t necessarily mean you should plant it. By October, especially in the warmer parts of South Africa, we need to start thinking differently. It is no longer only about what the temperature is today. We need to think about what the weather will be like in four, six or even twelve weeks’ time.

And that is where the time a crop takes to mature becomes very important. A vegetable planted in October may only be ready to harvest in December or January — right when our gardens are dealing with some of the hottest weather of the year.

Think ahead, not just about today’s weather

One of the easiest mistakes to make in spring is planting according to the weather outside your window. October might still give us some beautiful cool mornings and mild days, particularly here in the Western Cape. But ask yourself, how long will this crop take to grow, and what will the weather be like when it reaches maturity? If something needs 80–100 days to mature, an October sowing could still be sitting in your garden in January. That matters because many of our traditional winter vegetables simply don’t enjoy intense summer heat.

Think twice before planting these in October

Broccoli

Broccoli prefers cooler growing conditions. You may still be able to grow it in October in a cool position or cooler part of the country. Broccoli can take roughly 60–100 days, depending on the variety and whether you are starting from seed or seedlings. Plant it now and you could be asking it to form its head as temperatures climb towards summer. Heat can cause smaller or looser heads, and plants may mature much faster than expected. Rather save that valuable garden space for a summer crop.

Cauliflower

Cauliflower can be even fussier. It prefers fairly steady, cool growing conditions while developing its curd. High temperatures and stress can result in small, loose or poor-quality heads. Some varieties can take 70–120 days or longer from seed. That means a cauliflower started in October may have to get through increasingly hot conditions before you get anything worthwhile from it. For many warm-summer areas, I would wait for the next cool-season planting window.

Cabbage

Cabbage is a little more forgiving because varieties differ considerably, but once again, check the packet. Some cabbages mature relatively quickly while others can take three months or longer. The question isn’t simply, Can cabbage grow in October? The better question is, will this particular cabbage have enough time to form a good head before the real summer heat arrives? If you are determined to plant cabbage, choose a quicker-maturing variety and give it good moisture and some protection from extreme afternoon heat.

Spinach and other tender leafy greens

Leafy greens become a little trickier as we move towards summer. True spinach (Spinacia oleracea) is a cool-season crop and tends to bolt as the days become longer and temperatures rise. If you sow it late in spring, you may get a fairly short harvest before the plant sends up a flower stalk.

Swiss chard is a much better option for the warmer months. It handles heat far better than true spinach and, if you keep harvesting the outside leaves, can continue producing for months. Keep it well watered and mulch around the plants to help keep the roots cooler. Lettuce can also become difficult as temperatures climb. Heat can cause lettuce to bolt quickly, become bitter and produce smaller, poorer-quality heads.

But that doesn’t mean we have to stop growing leafy greens completely. One of my favourite summer tricks is to use the rest of the vegetable garden to create shade. Instead of planting lettuce and leafy greens in an exposed bed that receives hot afternoon sun, tuck them into places where taller summer crops will protect them later in the day. Tomatoes, beans growing up a trellis, cucumbers, sweetcorn and other taller plants can all create useful pockets of shade.

You don’t necessarily want deep shade all day. A position that receives morning sun but is protected from the harsh late-afternoon sun can make a big difference. Also remember that your garden changes as summer crops grow. A spot that is completely sunny in October may be shaded by a large tomato or climbing bean in December.

Peas

If you haven’t planted your peas yet, October is generally getting quite late to start them in many parts of South Africa, particularly where temperatures rise quickly heading into summer. Peas are a cool-season crop and perform best before the real summer heat arrives. Depending on the variety, they can take around 60–90 days to reach maturity. Plant them in October and they may only reach their main flowering and pod-producing stage when temperatures are already considerably warmer.

Heat can reduce flowering and pod production, and once sustained hot weather arrives, the plants can decline surprisingly quickly. Before sowing, check your local temperatures and the days to maturity on the seed packet. In cooler regions you may still have enough time, but in warmer areas it may be better to save that trellis space for a summer climber such as beans or cucumbers.

Broad beans

Broad beans are another cool-season favourite. They perform beautifully through our cooler months, but they don’t appreciate sustained summer heat. If you sow them too late, they can put plenty of energy into growing a plant only to reach flowering and pod development when conditions have become too warm. Rather put them back on your autumn planting list.

Coriander

You can sow coriander in October, but don’t expect it to behave the way it does in winter. As temperatures rise and days lengthen, coriander can bolt incredibly quickly. Instead of producing weeks of lush leaves, it suddenly sends up a flower stalk. If you really want coriander through the warmer months, sow small amounts regularly, keep it well watered and give it some afternoon shade. And remember — bolting coriander isn’t necessarily a failure. Let some plants flower for beneficial insects and eventually collect the coriander seed.

This is probably the biggest lesson I want you to take away from this. When deciding what to plant, don’t simply ask “Can I plant this in October?” Ask “How many days does it take to mature?” A crop that takes 30–40 days is very different from one that takes 100–120 days. Look at the days to maturity on the seed packet and count forward. If you sow something on 1 October and it needs around 90 days, you’re looking at roughly the end of December or beginning of January.

Now think about your garden at that time. How hot does it get? How much water will that crop require? Will it still be comfortable in those temperatures? Will it bolt before you harvest it? Could that same space be producing tomatoes, beans, cucumbers, baby marrows, sweetcorn or another crop that actually thrives in summer? Suddenly that seed packet gives you much more useful information.

This is another trap. Seeing vegetable seedlings at a nursery doesn’t automatically mean they are the best thing to plant in your particular garden right now. South Africa has very different growing climates, and even two gardens in the same suburb can behave differently. One garden may receive full afternoon sun and bake in December, while another is protected and considerably cooler. Use the nursery as a source of plants — not as your planting calendar.

October is when our garden starts shifting properly towards warm-season growing. This is the time when I want space available for crops such as tomatoes, peppers, chillies, aubergines, beans, cucumbers, baby marrows, pumpkins, squash and sweetcorn. These plants aren’t simply capable of tolerating warmer weather — they actually want it. And many of them will occupy that space for months. That is why I don’t want a slow winter crop sitting in one of my prime summer beds struggling through the heat while a tomato seedling is waiting for somewhere to go.

A planting calendar should always be a guide, not a rule book. Someone gardening in Cape Town has a very different October from someone gardening in Johannesburg, Durban, Bloemfontein or a cooler high-altitude area. Your microclimate matters too. So instead of memorising a list of vegetables that you “can” or “can’t” plant, learn to look at three things. The temperature the crop prefers. How long it takes to mature. What your weather is likely to be when it reaches maturity.

Once you start thinking like that, your planting decisions become much easier. October isn’t about squeezing in one last winter crop simply because there is an empty patch of soil. It’s about looking ahead. Summer is coming, the garden is getting warmer, and now is the time to give that valuable growing space to the vegetables that are going to love the months ahead.

Not sure what to plant next?

Knowing what not to plant is just as important as knowing what to plant. Our VanZylStead Guide to Growing Veggies was created to help you take the guesswork out of growing food at home. We cover everything from planning your veggie garden and preparing your soil to starting seeds, feeding, watering, dealing with pests, harvesting and so much more.

Whether you’re planting your very first veggie bed or you’ve been growing for years, the Guide is there to help you understand why we do things — not simply tell you what to do. Because successful gardening isn’t about getting everything perfect. It’s about understanding your garden, learning as you grow and making better decisions with every season. Ready to grow? Get your VanZylStead Guide to Growing Veggies and let’s make this your best growing season yet.

Happy Gardening Friends

Tash en die Familie