Q&A: irises

Horticultural advice from the experts at the RHS
Question: Last year I bought three big flag iris in wonderful colours. I planted them straightaway but this year, after I'd cleared away a lot of dead foliage, I can't see any flower spikes at all. Is it a bit early yet, or is it possible they won't flower at all?

I've planted them in full sun, and the soil is free-draining, so what could be wrong?

Answer: Having bought the irises in flower last year, you would expect them to be able to repeat perform this year. However, irises dislike disturbance, so they often miss a year’s flowering after planting, just while they get themselves established into their new positions.

Make sure they are planted with their rhizomes just showing on the surface of the soil so they can be warmed by the sun. It’s also important to clear away all brown leaves and debris from the rhizomes in autumn to allow air and light in and to prevent rots setting in. All should be well for next year’s flowering and it’s worth the wait for these fleeting, but wonderful heralds of summer.

Send your questions for the RHS to: gardenproblems@standard.co.uk.

Only a few questions per month can be answered. For further advice on handling problems in your garden, visit www.rhs.org.uk/advice/index.asp.

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