Insect frass for
houseplants — does it work?
Yes. Flytiliser is one of the best organic fertilisers you can use on indoor plants. Here’s how to apply it, how much to use, and which plants respond best.
The case for insect frass on indoor plants
Most houseplant fertilisers are synthetic liquid feeds — fast-acting, easy to over-apply, and capable of burning roots if used incorrectly. Flytiliser is the opposite: a slow-release organic material that feeds soil biology first and plants second, delivering nutrients steadily over weeks without risk of scorching.
The chitin content is particularly relevant for houseplants. Indoor plants are often stressed — lower light, dry air, restricted root zones — and therefore more susceptible to root rot, fungal issues and pests. Chitin stimulates the plant’s natural immune system, making indoor plants noticeably more resilient without any pesticide input.
It’s also odourless when dry — a genuine advantage for indoor use over other organic feeds like fish emulsion or liquid seaweed, which can be unpleasant in enclosed spaces.
Application rates for houseplants
How to apply: Scatter the frass granules on top of the soil around the base of the plant (not touching the stem). Water as normal — the moisture activates the frass and begins nutrient release. No mixing or diluting needed.
Timing: Apply only during the active growing season (March–October). Most houseplants slow right down in winter and don’t need feeding. Resume in spring when you see new growth.
Which houseplants respond best?
Monstera & Philodendron
Heavy feeders that respond visibly to Flytiliser. New leaf production accelerates noticeably within one growing cycle.
Pothos & Trailing plants
Fast-growing vines deplete soil nutrients quickly. Regular top-dressing keeps growth vigorous and foliage colour rich.
Peace Lily & Anthuriums
Flowering houseplants benefit from the balanced NPK profile. Supports both leaf health and flower production without excess nitrogen.
Ferns & Calathea
Sensitive plants that often react badly to synthetic feeds. Flytiliser’s gentle slow-release profile suits their need for consistent, low-level nutrition.
Succulents & Cacti
Use sparingly — ¼ tsp every 8 weeks in summer only. Too much nitrogen causes soft, unhealthy growth in succulents.
Herbs (indoor)
Basil, mint, parsley and chives all respond well. Keeps soil biology active which is particularly important in the confined root zone of a herb pot.
Tips for best results
Combine with repotting. When repotting, mix 1 teaspoon per litre of fresh compost. This gives new roots an immediate soil biology boost and reduces transplant stress.
Don’t fertilise stressed plants. If a plant is wilting, root-bound, or in recovery from overwatering, fix the underlying issue first. Fertilising a stressed plant often makes things worse. Wait until it’s visibly healthy and growing before applying Flytiliser.
Water before applying. Dry soil can mean nutrients take longer to activate. Watering before top-dressing ensures the frass has moisture to work with from the start.
Less is more. Flytiliser is gentle but consistent. Applying too much won’t cause immediate harm but won’t deliver faster results either — the slow-release profile means each application works for 4–6 weeks regardless of quantity above the recommended rate.
500g bag — £8.50
One bag treats dozens of houseplants for a full growing season. Free P&P over £20.