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Yes. Indoor plants collect a film of household dust that dulls the leaves, and a weak neem wash lifts it and leaves a soft, natural sheen rather than the hard gloss of a silicone polish. Neem is not used neat for this, though: the pure oil is thick, it floats on water, and on its own it leaves a greasy film. It goes on as a diluted wash, made one of three ways.
Ready-to-use neem leaf spray
No mixing needed. Shake the bottle, mist the leaves lightly, top and underside, and wipe with a soft cloth or leave to dry.
Water-soluble neem
A concentrate pre-blended so it mixes straight into water. One part to a hundred parts of tepid water, a capful of about 5 ml in 500 ml, makes a light wash. Shake well, use in the same way, and mix fresh each time.
Pure neem oil with liquid soap
Warm the oil until it pours, stir 5 ml of it into 1 to 2 ml of our liquid soap, then add a litre of warm water and shake to a milky blend. The full method, with the ratios for a richer mix, is on our leaf-shine spray page.
How and when
Work in the morning or evening rather than in strong midday sun, and let the leaves dry before the plant goes back to a bright window. Once a fortnight is plenty for dust. On a plant you have not washed before, do one leaf first and look at it the next day. There is more on timing on our when to apply page.
Which plants
Glossy, broad-leaved houseplants such as monstera, rubber plant, peace lily and philodendron take it well. Wipe rather than mist on fuzzy or very fine foliage, and keep it off open flowers. Roses and smooth-leaved succulents have their own pages.
The smell, and the solid bottle
Neem’s earthy smell is noticeable while the leaves are wet and fades as they dry. The pure oil and the water-soluble concentrate both set solid in a cool room; stand the bottle in warm water, cap on, for ten minutes and it pours again. Whatever you mix, use it within 48 hours and tip away the rest.