Should I top up planters?

[Mrsmunchofmunchington]

I notice that the compost mix in my large trough planters has really shrunk down over a couple of years.
Should I top it up?
The plants already in situ are roses, jasmine and clematis.
It was originally about 2/3 inches from the top and now is double that.
I want to put in some aubretia and wasn’t sure whether to top up first or of this would then upset the existing plants as would cover them up too much.

Hi. Yes it’s always a good idea to top them up if the soil sinks a bit. Be careful not to cover the stems of the plants any deeper than they should be planted through. It might be better to use topsoil mixed with a little compost rather than just compost through, as it retains water better and won’t sink as much over time. Compost can also give a good nutritional boost (because it’s rotted matter) and you don’t want too much this time of year because it will promote new growth which might be tender as we go into the winter. So ideally I’d use topsoil with a bit of compost now and then maybe a top dressing of just compost in the spring. It can also be very helpful to mulch with some horticultural bark chipping as this will protect the roots over the winter and help retain water in the summer. Good luck

Don't use regular topsoil from the garden though, as you will introduce pests and diseases. Better to go with John Innes No 3 compost, which is specifically formulated for long-term use in containers.

Thanks, have ordered some John Innes no 3.