Yummy and delicious, broccoli is a very versatile vegetable as the head and stem can be used in many dishes as well, the mature leaves in salads.

Broccoli is a good source of fibre and protein as well as containing iron, potassium, calcium, numerous vitamins and folic acids.

 A member of the Brassicaceae (brassica family), which also includes cauliflower, Brussels sprouts and cabbage.

It an be grown from seed or seedling, and is ready to eat within 50-80 days of sowing depending on variety.

Follow our seven easy steps to successful broccoli harvest including tips along the way.


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How to grow vegetables - Broccoli

When to plant:

These days broccoli can be planted in almost any area of Australia. Check your garden centre for local varieties.

1. In cool and temperate regions plant in autumn and winter for seedlings and late summer for seeds.

2. In warmer and tropic regions plant in autumn and winter for both seeds and seedlings.


  • Pick a position in the garden that receives at least 6 hours of sun per day in a sheltered position.
  • Ensure the plants are placed in a position away from high winds as broccoli plants are easily damaged.
Improving soil over winter Seasol Liquid Compost

How to prepare the soil.

Broccoli can be grown in all soil types from sandy to clay soils, however the soil must be free-draining. If the soil doesn’t drain easily, create raised soil mounds to plant the seeds or seedlings into.

Follow the steps for successful soil preparation:

  1. Add well-rotted manure and compost to the soil and dig it in to a depth of 20cm. For a no-dig option use Seasol Liquid Compost.
  2. The PH of the soil should be neutral to slightly acidic around 6-6.5. If it’s too low, add a handful of lime per square metre to the soil.
  3. To boost the soil add Seasol Plant + Soil Booster and a fertiliser rich in potassium such as PowerFeed Controlled Release Tomatoes & Vegetable, so there is a supply of nutrients for plant growth.
  4. Water in well and if possible but not essential, let the soil rest for a week or so.
How to grow vegetables - Broccoli

Step 1.  Sowing seeds.

Seeds can be sown directly into the ground or seed trays. If it’s cool consider placing seed trays in a green house or inside on a heated mat.

In the soil, sow 2-3 seeds every 15cm in rows 30cm apart and to a depth of about 10cm.

In seed trays, fill the trays with seed raising mixture and put 2-3 seeds in each single cell. If using a seedling punnet, plant evenly across the punnet every 7-10cm, sowing two rows to a depth of 10cm.

Once sown, water the soil with Seasol to help increase seed germination rates. Mix 30mL of Seasol concentrate per 9 litres of water (stand watering can).

How to grow vegetables - Broccoli

Step 2 – First growth.

  • Seeds will start to emerge out of the soil within 5-10 days depending on temperature. The warmer the temperature the quicker the seeds will germinate.
  • Use a heating pad indoors for faster seed germination.
  • When broccoli sprouts, they only have two leaves. These seedlings leaves or cotyledons look like two fat hearts on either side of the stem.
  • Ensure your tiny plants are well watered every day. Do not let the soil or the seed raising mix dry out.
  • Apply Seasol weekly as this will help to stimulate strong root development and promote healthy growth.

Note: This is not a broccoli plant, it has been included to show seed germination.

Step 3 – Baby broccoli seedlings.

  • About two weeks after the seed leaves have opened up, the true leaves will appear, these look like tiny broccoli leaves.
  • At this stage thin out the weaker seedlings so that they are not competing for nutrients and space.
  • Broccoli seedlings are hungry little critters so give them a good feed with PowerFeed PRO SERIES Plant Food  Tomatoes & Vegetables.

Step 4 – Broccoli seedlings ready for transplant.

  • Transplant your own seedlings when they have two sets of leaves or more and are 10-15cm in height. Or transplant already grown seedlings from the punnet you have purchased from the hardware or garden centre.
  • Plant the seedlings at the depth they were in the punnet. If they look a bit leggy and stretched, plant deeper covering the two bottom leaves.
  • Water your newly transplanted seedling in with Seasol to get them over transplant shock.
  • Continue to feed your broccoli once a week with a liquid fertiliser such as PowerFeed PRO SERIES for Tomatoes & Vegetables.  Mix 20mL of PowerFeed concentrate with 9 litres of water (standard watering can).
How to grow vegetables - Broccoli

Step 5 – Broccoli seedling plants.

  • Watch your broccoli plants grow over the following weeks as the stalk develops, the leaves mature and the tiny head starts to appears.
  • Broccoli plants like to stay moist, so check the soil moisture daily and water if necessary. Water the soil around the seedlings in the morning, not the foliage to ensure the plants are dry by nightfall and not susceptible to diseases such as powdery mildew.
  • Apply a layer of mulch such as sugar cane mulch or peas straw to keep the soil warm and the moisture within the soil. The mulch will slowly breakdown overtime, improving the soil.
Seasol Commercial Broccoli trial report

Step 6 – Broccoli flower growth.

  • The head is the part of the broccoli plant that we eat. It is actually a tight collection of unopened flower buds.
  • Every 6-8 weeks apply another application of PowerFeed Controlled Release Plant Food Tomatoes & Vegetables to produce a bumper crop.
  • Additionally liquid feed plants with a combination of Seasol and PowerFeed every week. Mix 30mL of Seasol and 50mL of PowerFeed  concentrates per 9 litres of water (standard watering can)
  • Check soil moisture daily and water when necessary.
How to grow vegetables - Broccoli

Step 7 – Broccoli harvest

  • General harvest will start about 10-12 weeks aftering planting. The head will be around 15-20cm across with tightly closed green buds.
  • Cut the head at an early stage before the flower buds fully develop and open up giving you a nice tight head of broccoli.
  • Once heads have been harvested, store in fridge to ensure the broccoli stays crisp until it’s used.  Enjoy!
  • Small side shoots lower down the main stem will start to produce new heads so keep up the feeding and watering.
How to grow vegetables - Broccoli

Things to watch out for!

  • Hungry caterpillars love to chomp on your plant’s leaves. Keep a close eye on these little creatures and pick them off with your hand. Fine nets over plants can deter caterpillars.
  • Diseases such as various rusts, rots, mildew and leaf-spotting disease can occur. Spray with the appropriate sulphur or copper spray or use an organic spray.
  • Inconsistent watering and feeding and high temperatures can cause head to flower prematurely (bolting) and may not be worth eating. Broccoli forms yellow flower.