Question: I’m new to gardening in Brisbane, and I want to grow prince of Wales’ flower. Reply: I reckon prince of Wales’ feathers is one of the most beautiful of tropical ornamental vegetables. It’s often planted at Roma Street Parkland as an ornamental during the warm seasons.
I started growing Celosia argentea var. plumosa when I was a teenager and gardened in London. I grew them and coleus as a cash crop in my greenhouse. I sold them to a local family hardware store as individually potted plants just as the flower spikes were beginning to develop some colour. I needed the cash to pay for the fuel consumed keeping the greenhouse frost-free in winter because it housed my succulent collection and I grew winter vegetables, like French beans and salad vegetables.
Celosia are typical tropical annuals, completing their whole life cycle within a few months. Celosia germinate freely at 25C, growing best in subtropical Brisbane between October and May.
Celosia flower spikes and leaves are edible when young and tender. Sow thickly in spring or summer, either in pots or trays or directly in a prepared seed bed. Use fresh propagating mix for pots and only cover seed with a single layer of vermiculite.
Celosia seed need good sunshine and regular watering to help germination, and plants need a location on a balcony or in a garden with at least six hours of full sunshine to thrive. Give them freely draining, fertile, well composted soil. The compost is vital for conserving moisture.
Lightly rake the seed into the surface, but do not bury it. Sprinkle a veneer of chopped sugarcane over the surface, again avoiding burying the seed. Do not cover the surface by more than 50% using chopped organic sugarcane. This veneer of mulch helps conserve moisture without blocking too much of the sun’s warmth. Seedlings should be checked daily for watering, and try to only water in the morning. If the weather is hot, sunny, dry and windy, a second, lighter watering may be required again around midday.
Sow thickly, and then thin the seedlings every fortnight to progressively give each plant a little bit more room to grow. You can cook the thinnings like spinach. In South and South East Asia you’ll find them sold by the bundle as a fresh vegetable.
Later on, young, unexpanded flowerheads can be dipped in batter and deep fried: they make a nice entree with a ginger dipping sauce in Vietnamese cooking, or they can be served as a side dish with malai kofta, a mild and tasty curry.
Lastly, you can reliably save your best plants as a pretty source of seed for next year because they come true to type. The butterfly-attracting flowers can also be dried or used as fresh cut flowers.
Germination takes seven to fourteen days, during which it’s important to water the seed bed twice daily during dry conditions.
Thin the seedlings as they grow, if they grow too thickly this can encourage disease. As plants gradually mature you can reduce the frequency of watering to once daily. By harvesting the seedlings as you thin them you can enjoy them at their best quality for eating. Then, once each plant has reached about 15cm wide, stop thinning them and enjoy them for their colour.
Celosia may be nibbled by caterpillars. Non-hairy caterpillars can be squashed, but never handle hairy caterpillars with bare hands. Wear gloves, as the hairs may cause skin irritation or rashes, needing treatment with anti-histamine. In Brisbane many caterpillars feed at night, so don’t be surprised if you need a torch to find pests.
Feed fortnightly using seaweed solution. Good quality seaweed solutions contain between 50 – 60 minerals and beneficial, plant-based compounds useful for robust, healthy plant growth, especially useful for celosia.
When the central flower spike starts looking less intensely colourful, it can be allowed to dry off and ripen its seed. In damp weather, I use an electric herb drier, but always place seed heads somewhere warm, dry and well ventilated. Remove any debris from the seed, make sure they are completely dry and store them in an air-tight, resealable container (like a small jar) in the fridge. This way seed remains viable for three years.
Some growers like to pinch out the growing points (known as ‘stopping’) two or three times to force the plant to make multiple small flowerheads on a bushier plant rather than a single large flowerhead on an upright plant.
If you want a crackling display of prince of Wales’ flower for Australia Day, sow them in early December.
16th December 2012