Few British gardeners have taken to carnivorous plants. They are plants that are seen as needing arcane cultivation techniques that are known only to geeky adolescents or wrongly perceived as delicate exotics that are difficult to grow. In fact many are vigorous, hardy plants that demand no more special care than do roses or pelargoniums. One group of plants, Saracenias, are the national flower of Newfoundland, a testament to their hardiness. But they are rarely seen in British gardens.
In overlooking carnivorous plants we are missing out on some wonderful superb garden plants. There are few flowers as elegant as those of Sarracenia flava or as intriguing as the sparkling rosettes of the Drosera genus. Maybe if we stopped thinking of them as carnivorous we might view them through fresh eyes.
Carnivorous plants are found around the world, form North America to south-east Asia. There are even British native forms. In the south west of England there are several Drosera species, with leaves as sticky as flypaper and pitcher plants grow in peat bogs in Scotland. In general, plants grow in poor, acidic soil that is constantly moist.
To mimic these conditons plants in the garden or in pots must be kept constantly moist. Rainwater must be used: tapwater is too full of minerals and nutrients and will kill carnivorous plants. A sunny situation is also essential and Matthew recommends a site that receives at least four or five hours a day. Finally, carnivorous plants that are grown in pots indoors should be kept cool during the winter and allowed a period of dormancy.
Their particular water requirements mean that they are not plants that can benefit from the mass distribution and marketing of the garden centre chains. Most garden centres don’t have the resources to irrigate with rain water or to keep plants constantly moist. If you do find a carnivorous plant in a garden centre, chances are it has been mistreated and will never thrive. To be sure of getting vigorous, healthy plants buy direct from one of the growing band of specialist growers. The precept that for a garden to flourish you need to start with well-grown and healthy plant is even more true of carnivorous plants.
Three easy-to-grow carnivorous plants.
There are three main groups of carnivorous pants: those that have slippery ‘pitchers’ that insect fall down; those that have sticky substances that trap insects and those with mechanical traps that ensnare their food. Here is a plant from each group that is easy to grow.
Sarracenia pupurea ssp purpurea
Vigorous and hardy enough to be grown outdoors. It has dark red mop cap flowers that are typical of the genus and a rosette of short, fat pitchers about 15cm tall. The tubes of the plant are green overlaid with dark red veining. Between March and October they need to be kept in wet compost.
A mass of narrow leaves up to 10cm long, this is another vigorous plant that is easy to grow. The leaves are covered with droplets of a sticky substance that resembles dewdrops. They are very effective at controlling whitefly in cold greenhouses or in cool conservatories. Flowering weakens the plant so remove the flower stems for the first couple of years to build up a strong specimen. After that the plant should send up sprays of small pink flowers in the spring that produce viable seed.
The Venus Fly Trap is probably the most well-known of carnivorous plants. When it is grown well it is an attractive plant. It must always be stood in a saucer of rainwater (never tapwater), and always kept cool. Pinch out the flower spikes as soon as they appear until the plant is a few years old. Trying to artificially trigger the traps with a pencil of finger will weaken the plant and lead to its early demise.
Growing in small spaces
If your garden doesn’t provide the right growing conditions or if space is tight you can grow a collection of these plants in a large pot. The ideal container is a half-barrel or rubber trug but a large terracotta pot or patio planter would work just as well.
Cover the bottom of the container with a 15cm deep layer of perlite followed by a 5 cm layer of sphagnum moss peat or peat-substitute. Fill the rest of the pot to within a mixture of 1-part horticultural grit, 1-part perlite and 4 part peat or peat-substitute. Place it in a sunny part of the garden and fill with water from a rain butt.
If you are using a container that does not have a drainage hole in the bottom the drill a couple of holes about 5cm down from the surface of the soil to allow excess water to drain off
Choose hardy varieties of plants and in bad winters move the pot into a garage, shed or cold greenhouse.