Growing cauliflower: where, how & the best companion plants

Sebastian
Sebastian
Sebastian
Sebastian

As a horticulture student I mainly studied crops and cultivation techniques. It fascinates me how many diverse plants can grow from small, nearly identical seeds.

Favourite fruit: blueberries, grapes, raspberries, pears
Favourite vegetables: mushrooms, peppers, kohlrabi, onions, garlic

Cauliflower has a bit of reputation among hobby gardeners for being a tricky vegetable to grow. If you keep a few tips in mind, you will find yourself successfully growing your own cauliflower in no time!

Person planting out cauliflower
Cauliflower is certainly one of the more demanding vegetables [Photo: zlikovec/ Shutterstock.com]

Cauliflower (Brassica oleracea var. botrytis) is a member of the Brassicaceae family and looks similar to broccoli (Brassica oleracea var. italica). It is easy to digest, contains many valuable nutrients and has a subtle flavour. Just like with broccoli, you can eat the flower head of a cauliflower. Find out all about where and how to grow cauliflower yourself as well as which plants make the best cauliflower companion plants.

Growing cauliflower: where and how

Growing cauliflower can be challenging, but with a little patience you too can cultivate this highly nutritious vegetable yourself. Cauliflower requires nutrient-rich soil and plenty of water. It likes a warm and sunny spot with sandy, loamy soil that is well-draining and rich in humus.

Cauliflower being grown in raised bed
It is also possible to grow cauliflower in pots or raised beds [Photo: Nura M/ Shutterstock.com]

Growing cauliflower in the garden

While cauliflower prefers sunny spots, it can also do well in partial shade. Before planting cauliflower, it is best to loosen the soil. To ensure a healthy soil life, you can enrich the soil with compost or apply a plant-based fertiliser, such as our Plantura All Purpose Plant Food. This granular fertiliser lasts in the soil for a long time and will supply your cauliflower with all the nutrients it needs to thrive.

Growing cauliflower in pots

To grow cauliflower in a pot, choose a deep container with a diameter of at least 30 cm and a drainage hole. As cauliflowers need plenty of nutrients to grow well, it is best to plant it in nutrient-rich soil, such as our Plantura Organic Tomato & Vegetable Compost, for instance. For better drainage and to help prevent waterlogging, mix in about a third of expanded clay. Alternatively, you can also fill the bottom of the pot with a drainage layer of coarse material such as clay shards or stones.

Plantura Organic Vegetable Compost
Plantura Organic Vegetable Compost

Peat-free & environmentally-friendly: for tomatoes & all other vegetables, ensures a rich & aromatic harvest, child & pet friendly

When is the best time for planting cauliflower?

To grow your own, you can either sow cauliflower seeds or buy seedlings. The best time for planting out cauliflower seedlings is in April. If growing your own cauliflower from seed, you can start sowing them in a warm place as early as February. If you wish to harvest your cauliflower in summer, sow the seeds from the end of April to mid-May. For harvesting in autumn from around September, start the plants in June.

There are many different types of cauliflower to choose from. Check out our article for an overview of the different cauliflower varieties that you can grow in your garden.

Tip: In the right conditions, you can also sow cauliflower seeds directly outdoors starting mid-April. However, we do not recommend this as the plants grow more evenly when sown ahead of time. This also helps prevent your cauliflower from bolting too early and protects the seedlings against cabbage pests.

Person carrying tray of cauliflower seedlings
Pre-cultivation is definitely better than sowing cauliflower seeds directly outside [Photo: zlikovec/ Shutterstock.com]

How to sow cauliflower from seeds

February is a good time for sowing cauliflower seeds. For this, you can either use seed trays or pots depending on how many you want to sow. To ensure your cauliflower seedlings develop well, it is essential to use a low-nutrient growing soil, such as our Plantura Organic Herb & Seedling Compost. This allows the roots to grow stronger, leading to a more robust plant. Cover the seeds with no more than 5 mm of soil. The optimal germination temperature lies at around 15 to 20 °C. If sown in February, it takes about two to three months for the seeds to grow – only one month if sown from April onwards. As soon as the first true leaves are there, prick out the cauliflower seedlings and plant into a more nutrient-rich substrate, such as our Plantura Organic Tomato & Vegetable Compost. Once the fourth leaves have developed, it is time to plant out your cauliflower.

Cauliflower seedlings in tray
Before planting your cauliflower seedlings, they must be strong and healthy with a sturdy stem [Photo: Doidam 10/ Shutterstock.com]

Summary: Growing cauliflower from seed to mature plant

  • Start growing cauliflower from mid-February onwards
  • Cover the seeds with max. 5 mm of loose soil
  • Optimal germination temperature: about 15 to 20 °C
  • Water carefully and evenly, avoiding waterlogging
  • Prick out once you see the first true leaves
  • You can plant cauliflower from April to August

Tip: If you like growing cauliflower, why not try growing romanesco. It is very similar to cauliflower, but has a slightly stronger taste.

Planting out cauliflower

Before you plant out your cauliflower, you must harden off the young plants, especially when planting in April. To do this, place the plants outdoors into a frost-free, partly shady spot one week before planting out. Wait for the young plants to grow at least four leaves (in addition to the ‘seed leaves’ known as cotyledons) before planting out. Cauliflower is usually planted between April and August. If frost is forecast, cover your plants with fleece, for instance, to protect them.

When planting cauliflower, make sure that the soil is moist and to plant all of young plant’s soil as well as the whole root ball into the bed. Leave a planting distance of around 40 to 80 cm between individual plants to allow them enough room to grow.

Cauliflower seedlings in soil
When planting, make sure you cover the entire root ball with soil

Cauliflower and mixed cultivation

Not all plants are suitable for mixed cultivation. Here is an overview of some suitable and unsuitable cauliflower companion plants:

Good cauliflower companion plants:

  • Celery (Apium)
  • Spinach (Spinacia oleracea)
  • Peas (Pisum sativum)
  • Lettuce (Lactuca sativa)
  • Endive (Cichorium endivia)
  • Carrots (Daucus carota subsp. sativus)
  • Beetroot (Beta vulgaris subsp. vulgaris)

Bad cauliflower companion plants:

  • Onions (Allium cepa)
  • Garlic (Allium sativum)
  • All types of cabbage (Brassica)

To avoid depleting the soil of nutrients, only grow cauliflower in the same bed every two to four years. Also refrain from growing any other type of cabbage in the meantime to decrease the risk of soil-borne diseases such as clubroot (Plasmodiophora brassicae).

For many of us, the best bit about growing your own vegetables is harvesting them! In our article on harvesting and storing cauliflower, we offer tips on how to get the most out of your harvest.

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