Bloemkool is one of the most difficult vegetables to grow yourself. Many gardeners run into oversized plants or cabbages that stay very small. So in this blog, we are going to look at everything you need to know about successfully growing your own cauliflowers!
How to grow cauliflower
Sowing, growing, harvesting, varieties, pests.
General information
Cauliflower is part of the cruciferous family and is actually not even super old from around the 12th century. But here in the Netherlands, it has become a famous dish with some potatoes. Know for its white brain-like appearance and tasty flavors it’s one vegetable that was one of my most hated dishes when I was younger to one that I like to add to curries or just eat with some gravy.
When do you start?
Starting cauliflower has to be done at the right moment for a big harvest. This can be done at the earliest from mid-February to mid-March but keep in mind that this has to be done indoors. You can also start them in June for a late harvest or even in late July to get over the winter and have an early harvest in spring. For this, you have to choose hardy varieties!
How do you sow cauliflower?
Cauliflower can be sown directly or pre-sown. For pre-sowing, we recommend a deep tray like the Solid Deep 40 cell. Because they need warmth to germinate you are limited in starting time if you want to sow directly. Then you start in June. Then the soil is slightly warmer and the seeds will germinate. If you want to pre-sow, you can start in mid-February. They germinate from 8°C (36°F).
Sowing cauliflower is easy, if you choose to pre-sow in a seed tray you sow two seeds per cell and cut away the worst of the two once they have germinated. The seeds only need to be half to one cm under the soil. If you want to sow directly, sow two seeds every 40cm. Here too you remove the worst of the two. Keep in mind that the seeds can be eaten so you will have to protect them. It is best to use netting from day one.
When can you plant cauliflowers?
Cauliflowers germinate in as little as 6 to 10 days at ideal temperatures. But of course, they need to grow a bit more before they are ready to be transplanted. We usually take 4 to 6 weeks or when they have 3 or 4 true leaves (not the ones they get when they germinate). So you can anticipate this if you want a quick rotation in the garden so your beds are always full. You can plant them out about 2 weeks before the last forcing day, which is early May in the Netherlands.
How far apart should they be?
Cauliflowers like some space, so they can grow nice big leaves which they need to give a big cabbage in the end. If you make two rows, go for 30 to 40cm between the rows and also 30 to 40cm between the plants in the row. This way the cauliflowers can grow well and you will get a lot of harvests!
Cauliflower care
The care of cauliflowers is not very difficult, but there are some things to pay attention to in order not to get overshot or yellow cabbages. It is important that there is enough water and nutrition in the soil. Regular weeding is good to ensure that they do not have to fight for water and nutrients. Make sure the soil never dries out completely for a long period of time. This can cause the cauliflower to lag behind in its growth or even overshoot when it is a bit older.
Instead of lots of watering, look for a good rich soil life and enough organic matter to retain the moisture. Add a layer of compost of about 2,5cm on top of your garden before you put your plants in the ground. This will contain all the nutrients and make your garden a lot better at regulating water.
Types of cauliflowers
We all know cauliflower as the white large cabbage that looks a bit like brains. But you also have the Romanesco which can be found in stores more and more often. This is a pointy green cauliflower that is very eye-catching and also tastes delicious. Fun varieties to try:
- Alpha 7 (Suitable for early cultivation – White)
- White Gold F1 (Romanesco – Green )
- Walcheren Winter 5 ( Winter cultivation – White
Storing your cauliflower
It is and remains best to eat cauliflower immediately after harvesting. But sometimes you have so much cauliflower that you have to leave it somewhere. You can keep cauliflower in the fridge for about 3 to 4 days but after that, it will lose its flavor quickly. Luckily you can also freeze cauliflower. You can do this by baling the cauliflower. Cut the cauliflower into small florets and cook them for about 3 to 4 minutes. Drain quickly under cold water and let it dry well. Then it’s as easy as putting them in a zip-lock bag or container and freezing them.
Common pests
It is good to take a bit of time to talk about common pests with cauliflower. The most prominent is the white cabbage fly. Attracted by the scent of cabbages and known for its power to destroy the roots of young cabbage plants it’s definitely something to tackle early on in the growth of your plants. We suggest using fine mesh protection that can keep them out. Please note that they are vicious and taking off the netting for only 15 minutes can be enough for them to creep in. They are almost impossible to spot in the garden until it’s too late.
Next to cabbage flies you also need to beware of aphids. Even smaller than the white cabbage fly and almost impossible to avoid but easy to take care of. You can use various (bio) sprays that make easy work of them. We like to use Eco-style insect repellant or aphid repellant. One good spray on all sides of the leaves and they will be gone the next day.
When can you harvest cauliflowers?
The total time from sowing to harvesting cauliflowers is long, about 120 to 130 days. So you have to wait at least 4 months before you can harvest. If you start in spring from February to March you can harvest from June to July. If you grow over winter and start in June/July you can harvest in spring in April/May.
To know when they are ready is a matter of keeping a close eye on them. You actually have to harvest it just before it shoots through. The cabbage really only grows a lot in the last part of the plant’s growth. But, if there is too much direct sunlight on the cabbage it will start to sprout. To prevent this it is important to cover the cabbage. This is done by breaking off the lower leaves and folding them around the cabbage.
So just cover it up and check how it looks every other day. If it shows signs of bolting (turning yellow or forming blades) it is definitely time to harvest. Of course, you can also harvest based on how it looks. At some point, the cabbage is just beautiful and ready to harvest!