If you have a large annual or mixed annual border, then you know how expensive all the seedlings can be. I like to mix annuals and perennials because annuals usually continue to bloom right into the fall whereas many perennials have finished blooming by then. Some annuals seem to fit into a perennial border better than others. I like to use ones that have a more informal appearance like nicotiana, cosmos, and coreopsis. Most of the less formal looking annuals are also larger plants and so fewer are needed, costing less money.
One annual that fits into a mixed border very well is cleome (also called spider flower). The older types are quite tall, growing up to well over 1-1/2 metres. The flowers are said to look like spiders because as the blooms mature seed pods project out from the sides of them, resembling spider legs. These are tall, thorny-stalked plants that are planted about 30 cm apart so they soon fill up a large space, and the white, pink or violet blooms fit nicely into most borders.
The flower clusters are produced on the tops of the stalks and have a bit of a musky odour. Because of their height and also because toward the end of the summer the lower leaves of the open-pollinated types begin to yellow and drop, these are best positioned toward the centre or back of a border. They are often planted in groups of five or more to create drifts of colour and a more naturalized appearance.
Cleomes are undemanding and will tolerate any kind of soil and can endure drought quite well, but will perform best if supplied with adequate water during hot, dry weather. They are not particularly bothered by insects or pests and rabbits seem to shun them — perhaps because of the thorny stems, but do attract hummingbirds and butterflies. The flowers self-seed prolifically so you will have a steady source of seedlings in years to come — another cost-saving measure.
Due to gardeners’ demands, plant breeders created hybrids that are sterile, without thorns and about half the size of the old open-pollinated types, with dark-green foliage that remains attractive for the whole season.
Two of the new hybrids are Proven Winners’ “Senorita” series, the “Clio” series and the “Sparkler” series. The only one of these that I find listed in seed catalogues is the “Sparkler” series; the others, I assume, are patented and available only to growers, perhaps as cuttings. Cleome can be grown from seed and either the open-pollinated types or the “Sparkler” hybrid should be seeded six to eight weeks before planting-out time. The seeds require light to germinate so instead of covering them with planting medium, the seeds are simply pressed into the dampened soilless mix. The seed tray is covered to keep the planting medium moist and put in a warm spot — the seeds germinate best at temperatures above 25 C. They will take anywhere between 10 and 20 days and the rate of germination may be low so sowing a few extra seeds is recommended. Give the seedlings as much light as possible after germination and lower the temperatures to or slightly below room temperature.
Maybe you’ll try some of these attractive plants in you garden this year.