How to Grow Celosia from Seed: Helpful tips from seedling to showstopper

My first introduction to celosia was a bright fuchsia-colored bloom that looked like a piece of sea coral. This cockscomb variety was grown by friends who were selling dried flowers at a local farmers' market. I was mesmerized by the bright, colorful texture and shape of the cockscomb variety. Even after it dried, the color was vibrant. Both fresh and dried, celosia is a beautiful cut flower.

Celosia is fairly easy to grow from seed. Seeds can be started indoors 6 to 8 weeks before the last frost date. The seeds are incredibly tiny, and it is often easier to control germination and spacing by starting them indoors. 

Celosia seeds can also be directly sown outdoors. They prefer heat and light and should be planted after the soil has warmed up to at least 60ºF. Seeds germinate faster in temperatures between 65-80ºF.

Each variety of celosia is different, but they generally take 80 to 120 days to grow from seed, so starting seeds indoors can give you a longer blooming season. 

Giving your celosia the best growing conditions will result in more prolific blooms. 

Celosia is a warm-weather plant, so don’t be in a hurry to transplant it outside. They are not cold-tolerant, so nighttime temperatures need to be above 50ºF. Daytime temperatures should be consistently above 60ºF. Take the time necessary to harden off your celosia seedlings before transplanting them outdoors. 

Space celosia plants 6 to 12 inches apart. You can do a Florida weave style staking or use flower netting to hold plants upright. This is especially important for tall varieties and the heavy cockscomb varieties. These get top-heavy and are easily knocked over in a rainstorm.

Celosia prefers full sun for the biggest flowers. Heat and sunshine are what make these flowers thrive. Give them a place where they can get at least 8 hours of sunlight a day.

Like most plants, aphids and spider mites are going to be your most common pests. You may also get slugs, snails, and caterpillars eating the leaves. 

Root rot can kill celosia plants. Ensure the soil drains well to keep the roots from sitting in water for too long.

Mildew may also be a problem in very wet climates. 

The secret to harvesting celosia flowers for arrangements is to cut them when they’re mature enough to stand up on their own and before they have started to produce seeds.

You can start cutting celosia flower stalks as soon as the blooms reach the size you want. Keep a close eye on them at this point, because when the bottom of the bloom starts to brown or look dirty, it is developing seeds. 

When the flowers are fully mature, the seeds develop, and you’ll have a lot of seeds dropping out. This is why some florists don’t like to use celosia in arrangements. If you don’t want seeds all over your table, harvest celosia blooms before they start going to seed. 

Saving seeds is very easy to do with celosia since they are notorious for producing a bazillion seeds. You can let the blooms mature and save seed for replanting.

Celosia makes an excellent dried flower. The same harvesting rules apply. Although with dried flowers, you can shake out the seeds. Hang flower stalks upside down to dry.

Only pinch the branching varieties. Wait to pinch until they have been transplanted into the garden. Pinching off the top of the plant will encourage more branches. When the plant has multiple stalks, they are usually smaller, which is sometimes beneficial for using them in arrangements. If you are looking to grow one giant bloom, then you would not pinch back.

Celosia flowers are fairly easy to grow and have such interesting blooms. If you want a showstopper in your garden or unique texture for bouquets, add this colorful heirloom.