How to Grow Celosia Seeds

Grow Guide #2248
Family: Amaranthaceae
Binomial name: Celosia sp.
Life Cycle: Annual

This 'How to Grow' guide details everything a home gardener needs to know to plant, grow and care for Celosia (Celosia sp.).

Celosia varieties are classified by the type of flowers they produce and the number of stems they grow. In this guide, celosia plants are classified as plumed (Celosia argentea var. plumosa), wheat (C. spicata) or cockscomb (C. argentea var. cristata). Plumed varieties grow soft, feathery flowers on multiple stems. Wheat varieties have branched flower stems and feathery flowers. Cockscomb varieties grow a large, brain-like flower head on a single stem.

When to Sow Celosia Seeds

Celosia is a warm season flower. Use the table below to identify the best time of year to sow celosia seeds in your climate.

Preparation

Celosia plants are best grown in full sun. Choose a location that will receive at least 6 hours of full sun each day.

Celosia plants need a well drained soil enriched with plenty of organic matter. Prepare soil by weeding it thoroughly, digging it over to loosen it and adding aged animal manure or compost. Keep the area free of weeds until planting. Learn more about preparing soil for planting here.

How to Sow Celosia Seeds

Celosia seeds do not require any treatment (eg soaking, stratification) before sowing.

Celosia seeds can be sown directly into the garden OR seedlings can be raised in trays or other containers and transplanted to the garden once established.

Sow Direct

1. Sow seeds directly in the garden 3mm deep and 20cm apart.
2. Keep soil moist but never wet or dry.
3. Seeds should germinate in around 7-14 days at a soil temperature of 21-27°C.
4. Young seedlings will need protection from pests, pets and weather until they are established.

Raise Seedlings

1. Fill trays, punnets or jiffy pots with a good quality seed-raising mix, or use soil starter pellets.
2. Sow seeds 3mm deep.
3. Keep soil moist but never wet or dry.
4. Seeds should germinate in around 7-14 days at a soil temperature of 21-27°C.
5. Transplant seedlings to the garden once they have their first true leaves and are large enough to handle (usually 5-10cm tall).
6. Plant out, spacing plants 20cm apart.

Celosia is a tender crop that’s sensitive to frost. Do not transplant seedlings or sow seeds outside until all danger of frost has passed.

Optional: In cool climates celosia seeds can be sown indoors 6 weeks before the last expected frost. Grow them in a warm position with plenty of natural light.

How to Grow Celosia

Celosia plants may need watering during the growing season. Water when the soil is dry about 5cm below the surface (test this by scratching away a little soil with your finger). Water deeply in the early morning or late afternoon. Avoid watering the leaves of plants to avoid fungal diseases. Learn more about watering here.

If soil was well prepared no extra fertiliser should be necessary. In poor soil or to give your plants an extra boost, application of a high-potassium fertiliser or one formulated for flowering plants can be beneficial:

• Apply slow release fertiliser at the recommended rate when transplanting or when seedlings are 5-10cm tall.
• Apply liquid fertiliser at the recommended rate and frequency while plants are fruiting or flowering.

Cockscomb varieties only - Celosia plants may need to be supported as they grow. Depending on the expected size and height of the plant, use a stake, bamboo cane, trellis or string lines to support plants. Make sure you have the support in place when you sow seed or transplant seedlings to avoid disturbing the plant's roots later.

Plume and wheat varieties only - Pinch out the growing tips of celosia plants to encourage denser growth with stronger stems and more flowers. Using sharp secateurs or snips remove the top set of leaves, cutting just above a set of lower leaves.

Celosia plants should flower in approximately 85 days.

If growing celosia for cut flowers, use sharp snips or secateurs to cut the longest stems possible, removing the lower leaves and placing the stems immediately in a clean bucket of water. Learn more about cutting and conditioning homegrown flowers here.

Common Problems when Growing Celosia

Like all plants, celosia is susceptible to some pests, diseases and other problems. Below is a list of the most common problems gardeners encounter when growing celosia plants:

• 

  Aphids are small (2-4mm long) sap-sucking insects that congregate on the new shoots or the undersides of leaves. They can cause leaves to wilt or become discoloured, and also excrete honeydew which can attract ants and other insect pests. To manage aphids, remove them by spraying with a garden hose, apply a soap or alcohol spray, or encourage predatory insects to your garden. Read more about aphids here.
• 

  Bacterial leaf spot is a disease that causes irregularly shaped brown spots on all above-ground parts of a plant. The spots at first appear to be wet but become dry and scab-like over time. Leaves and flowers can fall prematurely. Water plants at soil level (not on the leaves), dispose of fallen leaves and fruit and practice crop rotation.
• 

  Slugs and snails are molluscs that feed on tender leaves and shoots, mostly at night, leaving slimy trails behind them. Control them by removing their hiding places, keeping free range poultry, collecting them by torchlight or by placing traps. Read more about slugs and snails here.
• 

  Spider mites (Tetranychus urticae), also known as two spotted mites, are sap-sucking arachnids that cause dry, wilted or discoloured leaves. The undersides of leaves may feel dry and a little like fine sandpaper. Prune plants to allow good air flow or spray with eco-oil or wettable sulphur. Learn more about managing spider mites here.