Celebrating Colourful Celosia – October
October 10, 2024
Sold on Celosia!
Flower-power in the tunnel-house!
How many times have you visited regions with a climate very different to your own, and marvelled at the flower beds you’ve seed there? It’s not that you don’t recognise the flowers you see, it’s just that, back home in your own garden, you know that you can never hope to achieve the same results. Climate dictates what we can and can’t grow to its full potential, but with a tunnel-house, you have it in your ability to control the factors that limit plant health. When you take control, blooms get bigger and showier, repeat blooming is more likely to occur, and blemishes and bug attack are less likely to be a concern. All of which means you get a great display which can be enjoyed whenever you visit your tunnel-house or take cut flowers or potted specimens indoors to be admired. If you really get keen on growing flowers undercover, why not ask local florists if they are interested in purchasing a few stems? You might find you have a small business in the making!
Celebrating celosia in its many forms
Celosia are a spectacular annual (annuals are plants that live for just one season). Their vivid colours make for a dramatic display in a vase, container, or flower bed, but perhaps the most astonishing thing about these eye-catchers is the range of shape their blooms exhibit. Celosia cristata is one of the most unusual in this respect, bearing bright, textured, crests of soft, velvety flowers that resemble the shape of a rooster’s comb. Cristata’s blooms come in shades of cerise, pink,orange, yellow, burgundy, red, and a frothy lemon-lime green. Celosia plumosa (sometimes called ‘Plumed Celosia’), bears bright feathery, long-lasting blooms in fiery colours ranging from red and golden-yellow to pink, bronze, and magenta. Celosia spicata’s soft pink shades are displayed on spiky yet elegant ‘spears’ that resemble an ear of wheat.
Let’s get growing!
Celosia are frost tender and won’t survive sub-zero temperatures. If sowing them from seed, do so 7-8 weeks before the latest expected frost in your region, or a little earlier with the help of your tunnel-house to protect the emerging seedlings. Seeds are very tiny. Fill a seed raising tray with finely sieved, commercially-prepared, seed-raising mix. Water it and leave it for 2-3 hours to drain. Use a pair of tweezers to space the seeds in groups of 3, 5cm apart, over the mix, then cover with 3mm of finely-sieved mix. Place a clear piece of plastic or glass over the seed container until the seeds germinate (this will prevent the mix from drying out). Remove the covering as soon as the first seeds germinate, and spray to keep the soil damp but not moist. Once the tiny seedlings have their first true leaves (leaves that resemble those of a mature plant), pluck out the 2 weakest from each group of 3, and discard. The seedlings are ready to transplant into their final position when they are 5-10cm tall. If don’t want to raise your own seed, or have left it a little late in the season to do so, purchase seedlings from a garden centre, ready to transplant into your tunnel-house (inspect them carefully for any signs of pest insects before you buy).
Planting
Container or tunnel-house bed?
If you plan to take your celosia into your home, when in bloom, to display them, you will need to choose containers to transplant your seedlings into. If you wish to use your celosia blooms as cut flowers, you will need to prepare a tunnel-house bed to receive the seedlings.
When growing in containers, you will need one pot of at least 200mm wide and the same deep, per plant. (Or you may choose to grow into tubs, spacing the seedlings 20cm apart.) Fill your container two-thirds full with a commercial mix designed for flower growing. Place your seedling into the container, taking with it as much of the soil around the roots as possible. Top up with mix, and gently firm around the base of the seedling (mix should come no further up the stem than it did previously). Water gently.
If you are preparing a tunnel-house bed for your celosia, start by weeding the area thoroughly. Use a fork to loosen the soil, and the back of a rake to break up any lumps. With gloved hands, fine up the soil until it is crumbly. Celosia like well-drained soil but won’t tolerate a dry bed. To achieve this balance, dig mature compost into the growing area. Stir in some sterilised animal manure and a scattering of slow-release fertiliser pellets, and water the bed well, leaving it to drain over night. Water again in the morning, and leave to drain for an hour. Use a dibber or trowel to create holes in the bed, 20cm apart on all sides. Transplant one seedling into each hole, taking as much soil as possible around the roots. Firm the soil around the base of the plant so it comes up the stem no further than it did in its previous growing site.
Feeding 70
Potassium helps plants to bloom well, and kelp is rich in potassium. Purchase a seaweed mix from the garden centre or make your own by half-filling a 9 litre bucket with chopped kelp. Top up the bucket with water and leave the kelp to soak for a week. Strain off the liquid and dilute it by 50% with fresh water before feeding it to each plant on a weekly basis until blooms open.
Maintenance
Water the container or tunnel-house bed when the soil is dry to a depth of 5cm. Encourage Celosia plumosa and Celosia spicata (not Celosia cristata) to bloom earlier and more profusely by snipping off their central growing point when the young plants are approximately 20cm tall (do this even if the section you are removing has buds on it). As you snip, be sure to leave at least 2 or 3 pairs of leaves on the plant. Celosia plants can grow tall enough to require staking to support them. Use ties or plant clips to anchor the stems to a slim but strong support.
Keep a watchful eye on your plants for signs of sap-sucking insects. Use your fingers to gently wipe off any you spot. If the situation looks like an infestation, spray with a soap and water spray made by dissolving half a teaspoon of hard bathroom soap in 1 litre of hot water. Leave to cool completely before using on the plants. Be sure the spray contacts the insects themselves. Spray the soapy spray onto the ground around the base of the plant, as well, as insects often drop down to this region when their host plant is disturbed.
Celosia enjoy a high humidity environment, so unless you are keeping humidity at bay for the health of your other tunnel-house plants, don’t be afraid to let your ‘jungle’ grow a little steamy! Spraying the celosias’ leaves with fresh water on warm mornings, and shutting the tunnel-house door overnight, will help create a humid environment.
Tips
The Celosia seedlings and seed purchased from a garden centre are great to experiment with, but to obtain plants that give stems of a length that are useful to a florist, research catalogues (such as that of Egmont Seeds) which offer ‘cut flower’ varieties.
Celosia can suffer from the shock of being transplanted, so grow twice as many seedlings as you require, and keep some back for replacing any that succumb.
Celosia prefer 6-8 hours of sunshine each day. To help container grown plants get their fair share of light in the tunnel-house, display them on tiered shelving.
When cutting blooms to take indoors, use sharp garden snips, and reach right down into the foliage to cut the stem at its lowest point.
Warning: Compost, animal manures, and garden soil can pose a risk to human health. Learn how to work with them carefully before using them in your tunnel-house.