Houseplant Potting Mix Recipes — 9 DIY Blends

1. Aroid Mix (monstera, pothos, philodendron, anthurium, alocasia, ZZ plant, peace lily)

• 40% peat moss or coco coir (base, moisture)
• 30% perlite (drainage, aeration)
• 20% orchid bark (medium grade) (chunky structure)
• 10% horticultural charcoal (filters water, prevents rot)

Aroids want airy, fast-draining soil that still holds some moisture. The chunky perlite + bark + charcoal combo gives roots air without leaving them dry. This recipe outperforms every bagged "monstera mix" at half the cost.

2. Succulent & Cactus Mix (jade, aloe, echeveria, haworthia, sedum, cacti)

• 50% pumice or coarse sand (drainage and weight)
• 30% regular potting soil or peat (small organic component)
• 20% perlite (extra aeration)

The standard gritty mix. The high mineral content drains quickly and dries thoroughly between waterings — exactly what succulents and cacti want. Bagged "cactus soil" is usually too peat-heavy; this recipe is the difference between a plant that survives and one that thrives for years.

3. Orchid Mix (Phalaenopsis, Cattleya, Dendrobium)

• 60% medium-grade orchid bark (epiphyte roots want bark, not soil)
• 25% perlite (drainage)
• 15% sphagnum moss (held water, not too much)
• Plus a small handful of horticultural charcoal

Phalaenopsis and most common orchids are epiphytes — their roots evolved to grip tree bark, not sit in soil. Standard potting soil kills them. This bark-dominant mix is what every commercial orchid grower uses. Pre-made orchid mix from a garden centre works too if you don't want to blend.

4. Tropical Foliage Mix (calathea, croton, dracaena, dieffenbachia, rubber plant)

• 60% peat or coco coir (base, moisture)
• 20% perlite (drainage)
• 20% orchid bark (fine grade) (light chunkiness)

Tropicals want more moisture than aroids but still need air. This blend retains water without sogging. Calathea in particular thrives in this mix; bagged generic mixes often hold too much water at the root ball.

5. African Violet Mix (Saintpaulia, streptocarpus, gloxinia)

• 50% peat moss (slight acidity they prefer)
• 25% perlite (drainage)
• 25% vermiculite (held moisture without bog)

African violets are picky — they want light, airy, slightly acidic soil. The peat + vermiculite combo holds the moisture they like; perlite stops it sitting too wet. Standard houseplant mix is usually too heavy.

6. Fern Mix (Boston fern, bird's nest fern, maidenhair, staghorn)

• 50% peat or coco coir (moisture across root mass)
• 30% leaf mould or fine compost (organic matter ferns evolved with)
• 20% perlite (drainage)

Ferns evolved on forest floors with constant gentle moisture and organic-rich leaf mould. This mix replicates that. The leaf mould is optional but lifts results noticeably — collect from a clean deciduous yard in autumn and let age six months.

7. Carnivorous Plant Mix (Venus flytrap, sundew, pitcher plant)

• 70% long-fibred sphagnum moss (or peat moss)
• 30% perlite (drainage)
• NEVER add fertilizer, lime, or regular potting soil

Carnivorous plants evolved in nutrient-poor acidic bogs — they catch insects because the soil gives them nothing. Adding fertilizer or any normal potting soil kills them. Use only rainwater or distilled water; tap water minerals also kill them. The recipe is strict but simple.

8. Bonsai Mix (juniper, maple, ficus, jade as bonsai)

• 50% akadama (Japanese fired clay; specialty item)
• 25% pumice (drainage)
• 25% fine orchid bark or kiryu (organic component)

The traditional Boon's mix. Akadama is the bonsai-specific ingredient that holds moisture but drains fast; substitute fine LECA at higher ratio if akadama isn't available. Most general-purpose bonsai survive in this; deciduous species may want more bark.

9. Bulbs & Indoor Herbs Mix (amaryllis, paperwhite, basil, rosemary, thyme indoors)

• 60% all-purpose potting soil (good base feeding)
• 30% perlite (drainage to prevent bulb rot)
• 10% coarse sand (extra weight, stability)

Both indoor bulbs and Mediterranean herbs hate sitting in wet soil. The increased drainage protects against rot while the base potting soil provides the moderate feeding both want. Mediterranean herbs (rosemary, thyme, sage, oregano) also benefit from this mix indoors.

Should I sterilise homemade potting mix?

For inorganic components (perlite, pumice, LECA) from sealed retail bags — no. They're already clean. For homemade compost or yard-collected leaf mould — yes. Bake at 90°C (200°F) for 30 minutes spread thin on a tray to kill fungus gnat eggs and weed seeds. Cool fully before mixing.

Do I need to add slow-release fertilizer?

Optional. Some growers mix in a teaspoon of slow-release granular fertilizer (Osmocote, Acti-Sol, etc.) per litre of mix; others prefer to liquid feed weekly during the growing season. Liquid feeding gives more control; slow-release is easier. For aroids and succulents, slow-release works well. For African violets and carnivorous plants, never add it — both are sensitive to nutrient overload.

Can I just add more perlite to bagged Miracle-Gro?

Yes — 50/50 Miracle-Gro and perlite makes a workable aroid mix in a pinch. Add a handful of orchid bark and you have nearly the proper aroid recipe. 30/70 Miracle-Gro/pumice makes a workable succulent mix. Bagged mix as a base + amendments is the most realistic path for casual growers who don't want to source 6 different ingredients.

Where do I find pumice in Canada?

Bonsai suppliers (Bonsai West, Mirai Forest) and specialty hydro shops are the most reliable sources. Some Canadian Tire and Home Depot stores carry pumice in the rock landscaping section — same product, less expensive. Look for the size labelled 1/8" to 1/4" granules. Coarse sand from hardware stores (HPC sand, sharp sand) is a cheaper substitute that works as well in most succulent mixes, with slightly more weight.