Growing Cauliflower in the Subtropics

Cauliflower is one of my favourite vegetables to eat and grow. The cauliflower growing season is very short in the Subtropics so having a successful crop of cauliflower hinges on timing and variety.

Choosing the right variety of cauliflower

Cauliflowers are one of those plants that will just bolt to seed if it’s too hot. As our winters here in Brisbane South East Queensland are quite short (or non existent) you want something that grows quick.

The trade off with quick growers, is they don't get as huge as supermarket ones. However nothing beats home grown cauliflower, so just remember to plant more. We primarily grow two different varieties here - Cauliflower Sixty Days and Snowball, both you’ll be expecting harvest within around 60-70 days. You can find all the varieties of cauliflower that we grow and stock here.

How to prepare your beds

The key is to grow them fast, which comes down to good soil prep. They are heavy feeders so if you want decent size heads you want to make sure your soil is well fed. We add compost, cow manure, blood and bone and an organic slow release fertiliser.

When to plant Cauliflower seeds

We always try to get our cauliflowers going in late February/Early March and keep our succession up until mid-late June (Southern Hemisphere). If you're in the northern hemisphere this will be late Summer & Autumn.

Seed raising cauliflower

We raise these in trays because summer can decide she wants another go in March. It's a bit safer having them protected rather than out in the sun. As it cools down you can successfully plant them direct in the ground if you prefer. Just remember to keep moisture up to them until germination and keep them safe from critters.

To transplant your seedlings, wait for the second set of true leaves, remove the first seed leaves and bury down to that point. This will help the roots become established and more sturdy.

Ongoing care

As they are heavy feeders, they will benefit from weekly liquid fertiliser such as a fish emulsion. I’d also recommend giving them a boost with additional manure and compost around that 40 day mark.

As the heads form, and if you love the snow white look, it’s a good idea to protect them by tying the outer leaves up over the head. Sunshine will generally make them go yellow, and if it gets too hot on them they will start to separate and go to seed. They are perfectly edible at this point just don’t have the tight heads you’re likely to be accustomed to.

Potential Issues

Being a member of the brassica family they are an easy target for cabbage moth butterflies, so keep an eye on them and squish any eggs you see (little yellow dots on the underside of the leaves).

Rats LOVE cauliflower heads so if you have a rodent problem, you may not get a harvest. It's hard to keep rodents out of gardens, but if you know you have an issue potentially making some rodent proof cloches to place over them at night will be helpful.

If you over plant, you may find an epidemic of aphids on you hands. Just check underside of leaves and squish the mothers with wings before it gets out of hand.

We always interplant with Fennel and Dill as a distraction technique for bugs. If you're a Dirt Lover you can grab my planting plans plus a tonne of resources on Companion planting inside the portal.

When to harvest

It’s worth noting that when the heads start forming things move pretty fast. Keep an eye on them as one day they’ll be tight little heads and the next they will be separated as they head to seed. You may miss the boat due to expectations of sizing, so keep in mind that some of these fast growing ones don’t get as big as what you normally expect.

If you do find your heads are way smaller than you are expecting it just means you didn’t feed them enough in the early days. So make sure next time you prep your soil well, and give them that boost in the middle of their growth phase.

Unlike broccoli that will give you lots of lovely side shoots once you've harvested the main head, the cauliflower side shoots just aren't as nice. Once the head is harvested, remove the plant and you've got space for something new.

Do you love to grow cauliflower? Let us know in the comments below.