Basic Potting Mixes - Cultivating Carnivorous Plants (2015)

Cultivating Carnivorous Plants (2015)

Basic Potting Mixes

If you are getting a plant that

is “bare root,” i.e. shipped

without any soil on its roots or

if you received a plant in slimy,

rotted soil, and you don’t know

what type of soil to use, default

to one part sphagnum peat

moss and one part sand or

perlite. But before you go out

and buy a bag of sphagnum peat

moss or sand, there are a couple

things to know. First, make sure

the bag of sphagnum peat moss

does not contain additives,

especially fertilizer. Although

carnivorous plants can be

fertilized, sphagnum peat that

already comes fertilized often

Some ingredients in carnivorous plant potting mixes include (clockwise

has fertilizer that is too strong

from top left): charcoal, coconut fiber, perlite, orchid bark, and long-fiber

for most carnivores and will kill

sphagnum. Sand and sphagnum peat are not photographed here.



them. Second, when buying sand, make sure it is not beach sand. Salt will kill carnivores (and most other

plants, too). The best sand to use for most carnivorous plants is coarse-grained, silica sand.

The other default potting media is long-fiber sphagnum moss. This consists of long strands of dried out

sphagnum, a type of moss which can be found in many carnivorous plant habitats. Nepenthes, Heliamphora, and

highland tropical Drosera usually prefer long-fiber sphagnum moss over the basic carnivorous plant mixture. It

is airy and allows more oxygen to get through to their roots.

The thing to know about long-fiber sphagnum moss is that comes in a few different varieties, all of which

are named after their location of origination. The best quality is New Zealand or Chilean. This moss is thick,

almost plush, has few sticks and other debris, and is often sold under the title “orchid moss.” Long-fiber

sphagnum from temperate regions, such as Canada, Michigan, or Denmark, is often thin, full of debris, and

less expensive than the New Zealand moss. Don’t be fooled. The cheap stuff will degrade within a year and

be more likely to carry pests. In contrast, a good New Zealand moss should last around three years.

In the following chapters, I go more in-depth about potting mixes. The key thing to keep in mind when

buying ingredients is to make sure there are no additives or fillers. Also, be suspicious of claims of

“sustainable” mixes which use materials not often found in carnivorous plant cultivation. A few years ago, the

International Carnivorous Plant Society’s journal published an article about using (mostly) different kinds of

hydroponic clay for the cultivation of Nepenthes. I - and several others - tried the suggested mix and saw,

contrary to what the authors wrote, that after a few months, our plants were clearly suffering.