Peat-free substrates for serious tropical plants
Genus-specific bark, coir and mineral blends from £4.99, rare aroids acclimatised under UK glass, and a calculator that tells you exactly how many litres you need.
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Rare & variegated specimens
Acclimatised in York with a UK Plant Passport.
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Repotting calculator
Litres, bags, pot sizes and a recipe for your room.
Calculate my mixShop by genus
Every genus has its own care card, troubleshooting table and matched substrate.
Monstera
Hemiepiphytic climbers from Central and South American forest, grown on in our Y…
7 varieties · family Araceae
Philodendron
The second-largest aroid genus, split in practice into climbers that want a pole…
8 varieties · family Araceae
Alocasia
Rhizomatous jewels from the forest floors of Borneo and the Philippines that dro…
7 varieties · family Araceae
Anthurium
Cloud-forest epiphytes with velvet leaves and thick aerial roots that want const…
6 varieties · family Araceae
Hoya
Epiphytic climbers that flower on the same spurs year after year, given bright l…
6 varieties · pet-safe
Syngonium
Quick, forgiving arrowhead vines whose colour and leaf shape are steered by how …
6 varieties · family Araceae
Begonia
From polka-dot canes on a windowsill to Bornean jewels that only thrive in a sea…
6 varieties · family Begoniaceae
Calathea & Maranta
Pet-safe prayer plants from the forest understorey whose leaf edges show every h…
7 varieties · pet-safe
Scindapsus & Epipremnum
The easiest climbing aroids to keep alive and some of the most rewarding to trai…
7 varieties · family Araceae
Aglaonema & Dieffenbachia
Understorey aroids that tolerate dimmer rooms than almost anything else with pat…
7 varieties · family Araceae
Rhipsalis & Epiphytic Cacti
Spineless forest cacti that hang from rainforest branches, want shade and regula…
7 varieties · pet-safeSpecialist substrates
2.5L from £4.99 · 5L £8.99 · 10L £15.99 · 25L £32.99. Mixed by volume each week from screened components.
AFP 38%100% peat-freeMonstera & Philodendron Mix
Our flagship chunky blend for climbing aroids: open enough that thick roots never sit in stagnant water, and rich enough…
AFP 26%100% peat-freeAlocasia & Corm Mix
A finer, moister blend for Alocasia's dense mats of feeder roots: steady water without the anaerobic, compacted core tha…
AFP 44%100% peat-freeAnthurium Epiphytic Mix
Our most open aroid blend, built for the thick, velamen-sheathed roots of velvet Anthuriums that would rather grip bark …
AFP 42%100% peat-freeHoya & Epiphyte Mix
A lightweight, fast-drying bark and pumice blend for the fine, wiry roots of Hoya, which bloom best when they are snug, …
AFP 22%100% peat-freeCalathea & Maranta Mix
Our most moisture-retentive blend, built on low-salt buffered coir for prayer plants and ferns that crisp at the edges t…
AFP 30%100% peat-freeTerrarium & Vivarium Mix
A peat-free take on the classic ABG recipe, built to stay open and alive for years under glass, where you cannot simply …
AFP 40%100% peat-freeCactus & Succulent Grit Mix
A 70% mineral blend for plants that store their own water: it drains in seconds, dries in days, and keeps swollen stems …
AFP 24%100% peat-freeEveryday Houseplant Mix
A sensible, oxygenated all-rounder for the plants most homes actually own, and a reliable base for anyone who likes to b…
How many litres do you actually need?
A 12cm Monstera going into a 15cm pot needs about 0.95L of fresh mix with its root ball kept, or 1.95L for a bare-root reset after rot. Add your whole collection, set your room's humidity and watering habit, and the calculator returns litres per blend, the cheapest bag combination, clear pot sizes and a component recipe you can print.
Rescue boxes
Healthy plants with cosmetic marks, lopsided growth or overstock, packed honestly and priced to match.
Classic rescue box
3 tropical houseplants in 9–12cm pots: Pothos, Philodendron, Syngonium and similar.
Rare aroid rescue box
3–4 collector aroids with scuffed or torn leaves but sound roots.
Variegated specimen box
2–3 variegated plants that sold out of perfect stock: think Albo, Aurea and Mint.
Why 100% peat-free, chunky aeration prevents root rot
Most of the tropical plants people collect, Monstera, Philodendron, Anthurium, Hoya, grow on tree trunks or in loose forest litter. Their roots are adapted to wet-then-airy cycles: soaked by rain, then drained within minutes. Put them in fine compost and the pores fill with water and stay full. Roots starve of oxygen, fine root hairs die, and Pythium moves in. That is root rot, and it is the single most common cause of death we see in plants sent to us for diagnosis.
Supermarket peat-free composts make this worse, not better. Many are built on composted green waste and fine wood fibre, measuring under 8% air-filled porosity once wet and slumping further within months. Our blends are engineered the other way round: a structural fraction of 12–18mm Orchiata bark, coco husk and pumice that does not collapse, a moisture fraction of buffered coir and worm castings, and charcoal to keep the mix sweet. Monstera & Philodendron Mix holds 38% air straight after watering.
- Orchiata Pine Bark 12–18mmStructural air pockets between particles; lignin-rich, so it holds its shape for 18–24 months30%
- Coco Husk Chips 8–12mmHolds water inside each chip while leaving air channels between them20%
- Coarse Perlite 3–6mmPermanent lightweight air space that never decomposes15%
- Volcanic Pumice 4–8mmMineral skeleton with internal pores; adds weight to stabilise plants on moss poles15%
- Horticultural Charcoal 5–10mmStable macropores and adsorption of some organic breakdown compounds10%
- Organic Worm Castings <2mmSlow-release nitrogen, microbial life and cation exchange capacity10%
Read the full substrate science or the root rot recovery protocol.
Why Growtropic
Acclimatised under UK glass
Imported and lab-grown plants spend weeks on our York benches adjusting to British light and humidity before they are sold.
Blended to a published recipe
Every bag lists its components by volume, its AFP and its pH. No mystery “premium compost”.
Biological pest control
Predatory mites and nematodes, not systemic neonicotinoids, so plants arrive clean and safe to handle.
Stock our blends in your shop
Retail-ready 2.5L and 5L pouches and 25L repotting-bar sacks at 45–50% margin. £150 ex-VAT opening order, carriage paid over £250.
Plants for offices & hospitality
Installed and maintained biophilic schemes from £125 a month, with fortnightly technician visits and free replacements.
Care & Root Lab
Field manuals from the glasshouse, written for British homes.
Questions we are asked most
Still unsure? Email care@growtropic.co.uk with a photo of the plant and its roots — the nursery team replies Monday to Thursday.
Which days do you send live plants?
Monday to Thursday only, with a 1pm cutoff for same-day dispatch. Plants never sit in a courier depot over a weekend. Substrate-only orders also go out on Fridays. Below 5°C we add a 72-hour heat pack and wood-wool collar; above 32°C we hold plants at the nursery until it is safe.
How much does delivery cost?
Economy Tracked (48 hours) is £4.99 and free over £60. Standard Nursery Express (24–48 hours) is £5.99 and free over £100. Priority next-working-day is £7.99 and free over £150. Trade orders over £250 ex-VAT travel carriage paid.
What is the 7-day live arrival guarantee?
If a plant arrives damaged, diseased or dead, send us photos within 7 days and we replace or refund it. The one condition: do not repot it during those 7 days. A freshly shipped plant needs a week to recover from transit before its roots are disturbed, and most apparent transit damage resolves in that time.
Why does peat-free potting mix matter for houseplants?
Beyond the environmental case, most tropical houseplants are epiphytes or hemi-epiphytes whose roots expect air. Dense compost, peat or green-waste, holds water around the roots and collapses over time. Our blends use bark, coco husk, pumice and perlite to keep 22–44% of the pot as air even straight after watering.
Do you supply shops and offices?
Yes. Independent plant shops, garden centres and florists buy our retail-ready pouches and 25L repotting-bar sacks at 45–50% margin from a £150 ex-VAT opening order. Offices, studios and hospitality venues rent maintained plant schemes from £125 a month.