Care & root pathology lab
Start from what you can see on the plant, find the most likely cause, then work through the protocol we use on our own glasshouse benches in York.
What is the plant telling you?
| Symptom | Most likely cause | Protocol |
|---|---|---|
| Yellow lower leaves, substrate still wet days after watering | Overwatering in a compacted, low-AFP mix; early root rot | Root Rot in Houseplants |
| Plant wilting even though the pot feels heavy and damp | Roots already lost to Pythium or Phytophthora; the plant cannot take up water | Root Rot in Houseplants |
| Supermarket compost stays soggy, smells sour and shrinks from the pot wall | Fine green-waste compost with almost no air-filled porosity | The Science of Peat-Free Substrates |
| Small black flies rising from the pot when you water | Fungus gnats (Bradysia) breeding in a constantly moist top layer | Eradicating Fungus Gnats, Thrips & Spider Mites with Substrate Engineering & Beneficial Insects |
| Silvery scarring and tiny black dots on the undersides of leaves | Thrips feeding and frass | Eradicating Fungus Gnats, Thrips & Spider Mites with Substrate Engineering & Beneficial Insects |
| Fine stippling, dull bronzed leaves and webbing near the petioles | Two-spotted spider mite in warm, dry air | Eradicating Fungus Gnats, Thrips & Spider Mites with Substrate Engineering & Beneficial Insects |
| Dark, water-soaked patches appearing a day or two after delivery in cold weather | Chilling injury in transit or on the doorstep | UK Winter Houseplant Care |
| Leggy growth, small new leaves and crisp edges from November to March | Winter light below 3 mol/m²/day combined with dry radiator air | UK Winter Houseplant Care |
| Monstera or Philodendron leaves staying small and unsplit | Nothing to climb; no aerial root contact to trigger adult growth | How to Build, Moisten & Extend a Sphagnum Moss Pole for Mature Fenestrations |
| Tissue culture plantlets collapsing within days of leaving the cup | Humidity dropped too fast, or agar left on the roots | How to Deflask & Acclimatise In-Vitro Tissue Culture Aroids (28-Day Protocol) |
| White crust on LECA or terracotta and brown tips on new leaves | Salt and limescale build-up from hard water and feed | Transitioning Soil-Grown Aroids and Alocasias to Mineral Semi-Hydro (Pon & LECA) |
| You never know when to water and keep guessing from the surface | Opaque pots hiding the root zone; no way to read moisture | Clear Slotted Nursery Pots vs Terracotta & Ceramic Cachepots |
Nine field manuals from the glasshouse
How to Deflask & Acclimatise In-Vitro Tissue Culture Aroids (28-Day Protocol)
A tissue culture plantlet has never had to control its own water loss. This is the four-week protocol we use in York to turn a cup of fragil…
Root Rot in Houseplants: Identification, Surgical Pruning & Oxygenated Repotting
Root rot is rarely bad luck. It is what happens when roots run out of oxygen in a saturated, compacted substrate and water moulds move in. T…
The Science of Peat-Free Substrates: Air-Filled Porosity (AFP), CEC & Why Supermarket Compost Kills Aroids
Peat-free is not the problem. Particle size and structure are. This guide explains the measurements that decide whether a substrate keeps ro…
How to Build, Moisten & Extend a Sphagnum Moss Pole for Mature Fenestrations
A climbing aroid left to sprawl stays juvenile. Give its aerial roots something damp to grip and the plant reads the signal it evolved to fo…
Eradicating Fungus Gnats, Thrips & Spider Mites with Substrate Engineering & Beneficial Insects
We have not used systemic neonicotinoids on our benches. We control pests by changing the conditions they breed in and releasing the animals…
UK Winter Houseplant Care: DLI Light Drops, Radiator Drafts & Cold-Shock Transit Recovery
A British winter gives a tropical plant a fraction of the light it evolved under, then dries the air with central heating. Most winter losse…
Clear Slotted Nursery Pots vs Terracotta & Ceramic Cachepots: Root Observation & Drainage Mechanics
Most overwatering is a visibility problem. You cannot see the root zone, so you water by guesswork. The pot you choose decides how much you …
Transitioning Soil-Grown Aroids and Alocasias to Mineral Semi-Hydro (Pon & LECA)
Semi-hydro gives roots a steady supply of water and air from an inert mineral medium, with nothing organic to rot or breed gnats. The transi…
Understanding UK Plant Passports & APHA Biosecurity for Online Houseplant Buyers
Every plant sent by post from a professional operator in Great Britain should arrive with a plant passport. It is a small label with a big j…