The information below is not exhaustive, and further detailed information can be found in my book, available (HERE)
The Three Golden Rules.
For the majority of temperate species, these rules should be adhered to.
Many of these plants are inhabitants of open boggy areas, and have little or no shade cover from surrounding vegetation.
They are therefore adapted to survive high light levels, and as a rule 5-6 hours of direct sun is required for healthy growth-especially the larger growing plants.
Bogs and marshes are obviously very wet places, and also suffer from a lack of nutrients as the abundance of water leeches the minerals required for healthy growth away.
Therefore, carnivorous plants have evolved to derive these minerals from the animals they consume. In cultivation these plants still require a lot of water. This has to be rainwater (although distilled or de-ionised water is fine).
Water softeners and filters should never be used and bottled water should also be avoided. Stand your plants in 1-2 inches of water during the growing season (assume this to be Valentine’s Day-Halloween), and keep them barely damp during the winter dormant season.
If you are away in the summer you can increase the level of water to the soil surface-remember, being bog plants these are one group of planys you cannot overwater!
3. Winter Rest
This should be cold! We keep many temperate species-Venus Fly Traps, Pitcher Plants (Sarracenia species), the Cobra Lily (Darlingtonia californica), some Butterworts (Pinguicula species), some Bladderworts Utricularia species), and some Sundews (Drosera species) in unheated greenhouses which have been as low as -10 degrees Celsius with no problems.
Some of these plants are completely hardy in the UK climate and can be kept outside in tubs, bog gardens, or pots. The Sarracenia also make ideal pond marginals.
The dormant period must be respected and if they are indoors your plants should be moved to a suitable position with a lower temperature. This could be a greenhouse, cold conservatory, porch, or shed or garage window.
As they are not actively growing at this time, a high light level is not necessary, and the compost should be kept barely damp, without allowing it to dry completely. When growth resumes in the spring move the plants back to their summer position.
Pitcher Plants (Sarracenia species).
Water: Rain or distilled/deionised water only. Stand in about 2-3 inches of water during the growing season (see above), and keep only damp over the dormant winter months when the growth dies back.Compost: Moss peat and lime free horticultural sand, or moss peat and perlite, to a ratio of 1:1.
Light: Full direct sun.
Temperature: During the summer months when the plants are in growth, they can tolerate extremely high temperatures, making them ideal for situations such as conservatories, greenhouses, sunny south facing windowsills (for lower growing species), and outside.
During the winter dormant period, most of the species die back to the rhizome to protect themselves from the cold. All species are cold tolerant and are completely hardy in the UK climate. Ours are grown under glass, but unheated where the temperature falls virtually to that on the outside.
The ideal place for these plants is therefore a sunny aspect for the growing season, and a cold position for the winter dormancy, either outside, or under cover in a greenhouse or by a garage window.
The Cobra Lily (Darlingtonia californica).
Compost: While this plant will grow perfectly happily in equal parts of moss peat and perlite/lime free horticultural sand, as well as in pure sphagnum moss.
Water: Rain or distilled/deionised water only. Stand in about 2-3 inches of water during the growing season (see above), and keep only damp over the dormant winter months when the growth ceases.
Light: Full sun to semi shade. In slightly shaded situations the pitchers will be taller than if they are grown in full sun.
Temperature: Being a hardy species, this plant is ideally suited to the British climate. It is ideal for growing outdoors or in greenhouses and conservatories. During the summer it can tolerate a high temperature but it dislikes warm roots. Indeed, we lost several hundred plants after they over heated.
A way to avoid this is to grow the plant in a deep container which covers the pot. During the winter the plant can tolerate very low temperatures and is often covered in snow in the wild.
The ideal place for these plants is therefore a sunny aspect for the growing season and a cold position for the winter dormancy, either outside or under cover in a greenhouse or by a garage window
The Venus Fly Trap (Dionaea muscipula).
Water: Rain or distilled/deionised water only. Stand in about an inch of water during the growing season (see above), and keep only damp over the dormant winter months when the growth dies back.Compost: Moss peat.
Light: Full direct sun.
Temperature: Being temperate, the UK climate is good for this plant. However, in winter when the plant goes through a dormant period, it should be protected from the elements by placing in a cold greenhouse, porch, or shed/garage window. As the plant is not in active growth at this time, full sunlight is not as essential.
If grown on a sunny windowsill, the dormant period must be respected and the plant should be moved somewhere cold between Halloween and Valentine’s day.
Flowers appear in the spring and summer, and should be removed when they are seen as they weaken the plant.
The Bladderworts (Utricularia species).
Terrestrial Species: All of the plants listed below will thrive on a sunny windowsill or greenhouse/conservatory with bright light. They require a very high water level, up to the level of the soil surface during the summer months, and at about half way up the container during the winter. Only use rain or distilled water.As mentioned above the Bladderworts are for cultivational purposes divided into three groups, each having different requirements. The majority of plants grown in cultivation are either terrestrial or epiphytic, and it is these which are generally easier to maintain.
High temperatures are not a problem in the summer and a winter minimum of 5 degrees Celsius (41 degrees Fahrenheit) will keep most species happy. They should be grown in a 50:50 mix of moss peat and horticultural lime-free sand, or plain moss peat.
They quickly spread through a pot and some species do not flower until they appear rather cramped.
Epiphytic Species: The epiphytic species are native to Central and South America. They include some of the most spectacular members of the genus, many with flowers which resemble orchids. In cultivation they generally enjoy a bright position, shaded from direct sunlight in the greenhouse or on a windowsill.
They like a high humidity which will be achieved by keeping the compost wet. They do not like to be as wet as the terrestrial species, and indeed should be kept in about 1 inch of rain or distilled water during the growing season, and just damp over winter when many species partially or completely lose their leaves.
A good substrate for these plants is straight sphagnum moss, and by growing the plant in a pond basket or similar, a good degree of air movement will exist around the roots. The leaves will also grow through the sides of the container-a situation which seems to suit these plants well.
The Sundews (Drosera species).
Many species are easy to grow in either a greenhouse or on a sunny windowsill, and while some are more exacting, the majority of species are extremely simple to cultivate.
The three golden rules will suffice for the temperate species, while others require a little winter heat.
It’s hard to be too specific, and each species should be considered individually, and there are distinct groups, all requiring different conditions. If you are unsure, please feel free to contact us.
The Portuguese Dewy Pine (Drosophyllum lusitanicum).
There are different methods of cultivation, but the one I find the most successful is to germinate the seeds in those peat/fibre pots, which one can find in the garden centre. They should be sown in a compost of equal parts moss peat and lime free horticultural sand, and buried to a depth of 5 millimetres. It is an idea to sow one seed to a pot to avoid any disturbance which would occur when pricking out seedlings.This plant has an unfair reputation for being difficult to maintain for any length of time, but its cultivation is actually simple. Because of the large stature of the plant and its dislike of unnecessary movement, it is best grown from seed, and a full grown, flowering plant can be raised in one year.
The seeds should be kept wet until they have produced their third or fourth leaf, and then transplanted-complete in their peat pots, in to large, 20 centimetre (8 inch) clay pots, or extra deep 2 litre plastic pots of the variety you see roses grown in. Block the hole in the base of the pot with a couple of pieces of crock. The peat pots can be buried up to their rims in the same compost as above. The roots of the plant will then grow through the peat pot and into the larger pot.
Position the plant in full direct sun and water from above with rain or distilled water. The compost should be allowed to dry somewhat between waterings, and in the winter months the time between watering can be many weeks. However, do not allow your plants to dessicate. In extra deep pots, the plants can be stood in a tray of rain water during the growing season. The depth of the container ensures the upper surface of the compost remains dry.
It is tolerant of a wide range of temperatures and can survive in an unheated greenhouse. In freezing conditions, the plants do become somewhat bedraggled, returning to their usual stance when the temperature rises.
The Sun Pitchers (Heliamphora).
A mix of equal parts moss peat and perlite is ideal.These plants thrive in the same conditions as the Sarracenia above, BUT with a couple of important amends. Firstly, the require a winter minimum of 7 degrees Celsius (45 degrees Fahrenheit), and secondly, they do not like overheating, and temperatures over 27 degrees Celsius (80 degrees Fahrenheit) are best avoided. Some species are a little more tolerant of higher temperatures, and these are best suited to the beginner where they can be situated next to the door of a greenhouse for good air movement. If you wish to specialise in these plants, a separate enclosure, or a terrarium, is recommended.
The Albany Pitcher plant (Cephalotus follicularis).
A mix of equal parts moss peat and lime free sand is ideal.This plant also grows in the same conditions as the Sarracenia, and is surprisingly cold tolerant. They are best kept above 2 degrees Celsius (36 degrees Fahrenheit).