Best Soil and Potting Mix for Carnivorous Plants
I grow nearly every genus of carnivorous plant, from Venus flytraps to highland Nepenthes to Heliamphora, using just five ingredients. No secret blends, no expensive additives. Just the right materials in the right ratios. Here's exactly what I use and how I mix it for each group.
The Five Things I Use
- Peat moss, the base of most bog plant mixes
- New Zealand long fiber sphagnum moss, high quality, for Nepenthes and anything that wants airy, moist roots
- Perlite for drainage and air
- Coconut fiber chips, washed well to remove excess salts
- Sand, and pool filter sand is my go to because it's clean and consistent
By adjusting the ratios of these five, you can grow nearly any carnivorous plant. If you'd rather skip the mixing, my pots come prefilled with the same peat perlite mix and sphagnum I use in the greenhouse.
Why Regular Potting Soil Kills Them
Carnivorous plants come from bogs, seepages, and wet sand where there's almost nothing to eat in the soil. That's the whole reason they evolved traps. Their roots aren't built for the fertilizer and minerals in a bag of regular potting soil, and it burns them. Anything labeled with "plant food," "moisture control," or added fertilizer is out. Same goes for garden soil and compost.
That doesn't mean these plants can never be fed. A light fertilizer like Nutricote used sparingly is fine. The problem is fertilizer baked into the soil itself, where the roots sit in it all the time. My fertilizing guide covers the right way.
What I Mix for Each Group
Venus Flytraps and Sarracenia
1 part peat to 1 part perlite or sand. Simple, reliable, and what my prefilled peat perlite pots use. Shop Venus flytraps or Sarracenia.
Sundews
A peat heavy mix with some perlite or sand for drainage. Cape sundews like Drosera capensis are forgiving and grow in almost any version of this.
Mexican Butterworts
The same ingredients, but grittier and faster draining. More perlite and sand, less peat. They rot easily in a mix that stays wet all winter. Shop Pinguicula.
Nepenthes
Long fiber sphagnum with perlite and washed coconut chips. They want moist roots with a lot of air. For a single plant, a pot prefilled with pure long fiber sphagnum works well. Shop Nepenthes.
Heliamphora
Mostly long fiber sphagnum with plenty of perlite. Open, airy, and constantly damp. Shop Heliamphora.
Nepenthes mira x villosa, sphagnum and chips — from $75
Drosera capensis Big Red, Meadowview, peat heavy mix
Choosing the Right Pot
Plastic or glazed ceramic, always with drainage holes. Skip terracotta, since it can leach minerals into the soil over time. For flytraps and Sarracenia, go deep. Their roots run down toward the water, which is why I use a tall 3.5 by 5 inch pot for most of my plants.
What I Use
Repotting and Keeping Soil Fresh
These plants don't need constant repotting, but I refresh the mix every one to two years. Peat breaks down and gets compacted, and even with pure water, some buildup happens over time. Spring, right as plants wake up from dormancy, is the best time. Between repots, an occasional flush with distilled water helps keep things clean.
If a plant is declining and you're not sure why, fresh media and pure water is the first reset I'd try. Here's how I water each group. Dividing plants during a repot is also the easiest way to make more of them. More on propagation here.
Keep It Simple
Carnivorous plant soil doesn't need to be complicated. Five clean ingredients, the right ratio for the plant, pure water, and a fresh repot every year or two. That's what I've done for over 30 years, and it works for nearly everything I grow.
Skip the Mixing
Pots prefilled with the same mixes I use in my greenhouse.
Happy Growing
Jeremiah Harris
Jeremiahsplants.com