Chelsea chop – Charlton and Blackheath Amateur Horticultural Society

Pat’s 10 jobs for May 2025

1. Border irises are really doing their thing now and the show can be brief but make sure to keep the soil around their roots free of weeds so their rhizomes can bake a bit in the sun.

2. Time to Chelsea chop your tall perennials to stop them flopping later or to extend flowering. Good candidates are Phlox, Penstemon, Helianthus, Sedum/Hylotelephium – and I include vigorous Clematis too. You can either do the whole plant at once or just some stems to extend flowering, although it may result in smaller flowers.

3. Deadhead displays of pot plants like Violas to keep them flowering and stop them going to seed. Remember to give them a feed to keep the display going.

Hylotelephium telephium 'Touchdown Teak'

Pat’s Jobs for May

1. It’s a good time to take softwood cuttings of both tender and hardy perennials such as pelargoniums, anthemis and penstemons. Place in a shady spot until roots begin to form.

2. Put plant supports in place to stop things flopping and make them yourself from shrubby prunings or just push prunings in the soil around the plant.

3. I’ve Chelsea chopped my phlox today and also done a few clematis as they are far too tall and leggy after all the rain we’ve had.