Potting Shed\

Welcome to my potting shed! This is the column where I’ll share all my gardening hints and tips – and I’ll try to answer any queries you may have.

Why have my Siberian irises failed to flower? – J Cooper, by email

Late frosts may have killed the flower buds, but congestion at the roots could also be the reason. Dig up and divide the rhizomes and replant in good soil.

What’s caused apples to fall from my tree? It looks healthy and I always water it during dry spells. – Marjorie French, Kilsyth

This is a natural process known as the “June drop” and it’s your trees way of thinning out a crop that’s too heavy for it to carry.

Would Tulbaghia survive in my garden? I’ve got a sunny courtyard in the centre of the city. – Mike Lawrence, Edinburgh