Are the blue ‘eggs’ at the base of my rhododendron causing growth problems?

Peter Wilson, by email

Stefan says: This is not the first time ‘small blue eggs’ have been implicated in a plant problem. The answer is always the same: the nursery that supplied the plant! The objects are slowrelease fertiliser granules that would have been in the compost when you bought your plant.

Small, more or less coloured objects are not uncommon in garden soil and compost. Sometimes they are snail or slug eggs, and pale buff or white in colour. On other occasions, the objects may be yellow, brown or even red and then they’re very likely to be the spore-bearing structures formed by harmless growths called slime moulds.

But whatever they are, they’ll cause no harm to your plant, and there must be some other cause for the poor growth of your rhododendron. It’s possible the soil is not sufficiently acidic.