When to plant
Carnivorous houseplants are available for most of the year, except during their Dormancy refers to a period of inactivity in plants, during which they slow down or stop their growth, conserving energy and resources. This is a natural process that helps them survive harsh conditions, such as winter or drought. Dormancy in seeds is a mechanism that prevents them germinating until environmental conditions are favourable for growth.
Hardy carnivorous plants are best planted outdoors in spring, when they are coming into growth. However, they should be fine planted at any time, except when dormant or when conditions are extremely cold or hot and dry.
Where to plant outdoors
Suitable for:
Hardy carnivorous plants are best grown in a damp bog garden, lined with a perforated butyl liner and filled with low-nutrient specialist Can refer to either home-made garden compost or seed/potting compost: • Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own.
If you are growing several different types, choose species that like similar conditions and grow them together as a collection. Don’t mix them with more vigorous bog plants, as these may outcompete the carnivorous plants.
You can also grow them in containers, again in specialist compost. To keep the compost damp, you can stand the container in a saucer of rainwater, sink it into a bog garden, or place it in a shallow pond margin. Alternatively, use a container with few or no drainage holes, such as a butler sink with the plug in. Growing in containers means it’s easier to bring plants indoors over winter, if necessary.
There are species for most locations, from partial shade to full sun. Plants often grow more strongly and develop richer colours in sunnier locations. The taller pitcher plants, such as Sarracenia flava var. maxima, won't usually stand up to a windy site, so plant in a sheltered spot or choose lower-growing species.
Where to grow indoors
Suitable for:
Many carnivorous plants can be grown indoors, in a bright position but not usually in direct sun, as the leaves can scorch through glass.
Tender species that come from the tropics, however, need warm, humid conditions and often lower light levels. The most widely available is Nepenthes, which is usually grown in a hanging basket, where its dangling pitchers are displayed to best advantage.
Compost for carnivorous plants
Many carnivorous plants grow in the wild in boggy or swampy ground that is acidic and low in nutrients, so growers traditionally used peat-based compost. The use of peat is soon to be banned in the UK (why?), and more sustainable options have been developed in recent years, such as milled pine-bark, other fibrous materials such as coir, or sustainably farmed live sphagnum moss, combined with Sharp sand is washed, gritty sand used in potting compost mixes, This is sold for gardening and is not the same as builders sharp sand.
You can buy specialist peat-free compost for carnivorous plants from online suppliers and some garden centres. Ready-made composts will specify for which types of carnivorous plants they are suitable.
You can also mix your own compost – the ingredients are available from specialist suppliers online and from some garden centres. The exact combination of ingredients and their ratios are a matter for debate, and different formulas will suit different species, so it is worth experimenting.
Growing carnivorous plants in peat-free mixes
A research experiment growing Sarracenia in mixes of peat-free growing media has so far been successful, with some outstanding results. These mixes have been produced from the ‘Peat-free Carnivores’ experiment carried out by the RHS, which tested five different peat-free blends against a peat control. So far, all five peat-free blends have provided better results than plants grown in peat. The plants used in the research experiment are Sarracenia leucophylla A plant produced by crossing two distinct parents, often different species, to produce offspring that combine the characteristics of both. Hybrids can occur naturally, but crosses are often made deliberately by plant breeders to produce plants with better yield, improved flowering or vigour, or improved disease resistance.
In an effort to assess and qualify the longer-term benefits of peat-free cultivation, this research experiment continues at the RHS. However, from this study the RHS recommends using the following peat-free alternative mixes:
- Sustainably produced sphagnum moss – 75% by volume with 25% finely sieved pine
Bark is the outermost layer of woody plants (trees, shrubs and woody climbers). It is several cells thick and provides protection against physical damage, disease and environmental stresses. Bark comes in a wide variety of colours and patterns, and these can help gardeners when identifying plants. The fissures and crevices of bark on older plants also creates valuable habitat for many garden creatures as well as lichens and small plants.
- Sustainably produced sphagnum moss (dried and chopped) – 100%
The RHS research on peat-free carnivorous plant growing, supported by peat-free carnivorous plant nursery Floralive, is ongoing, and as we discover more we will share the results so people can continue to enjoy growing carnivorous plants. The RHS collaborates with industry and specialist growers, of which some have demonstrated long-term (30 years) consistent results growing carnivorous plants without peat.
Peat-free Sarracenia and other carnivorous plants are also being made available for purchase in our RHS Wisley Plant Centre.
Never plant carnivorous plants in soil or potting compost, as these are too rich for them.
How to plant outdoors
Most carnivorous plants are perennials and are easy to plant, in a similar way to other garden Perennials are plants that live for multiple years. They come in all shapes and sizes and fill our gardens with colourful flowers and ornamental foliage. Many are hardy and can survive outdoors all year round, while less hardy types need protection over winter. The term herbaceous perennial is used to describe long-lived plants without a permanent woody structure (they die back to ground level each autumn), distinguishing them from trees, shrubs and sub-shrubs.
However, unlike other garden perennials, they must be planted into compost that is specially formulated for carnivorous plants (see above), rather than soil or potting compost.
When planting outdoors, carnivorous plants are best grown either in a bog garden with a perforated butyl liner or in a container with few or no drainage holes. Again, only use compost that is specially formulated for carnivorous plants.
How to plant indoors
When grown indoors, most carnivorous plants can be kept in the container and compost that they were bought in, for at least the first year.
They may need repotting eventually, once their roots fill the container. Use a pot that is only slightly larger than the original one, filled with a compost mix for carnivorous plants.