I have several pelargoniums that need a prune as they have grown far too leggy. One is a Lord Bute Which is flowering now. how much can I prune now?
also I have a very leggy scented variety that is very leggy and brown stalks with only small leaves at the tips of the stems. How can I encourage this one to bush out and get more leaf and flowers?
thanks in advance
We usually unceremoniously hack back the ones at school (great for biology experiments). They are super tough. They go through the 6 week holiday with only being watered a couple of times. They soon send out new shoots from the first bud below the cut. Any offcuts get stuck into soil and root very easily to make new plants. They are just the regular bedding pelargoniums, I don't know how different to scented they are.
Pinching out the tips helps them to bush out
The scented ones are very diverse, in growth and structure, but all in all they are very tough too. The vigurous ones I chop back quite hard after tha main flush of bloom is gone. They bush out thicker than ever after that. These I also trim in spring and autumn.
The less vigurous ones, I trim back a node under each flower, no more, and they also react well. It helps them if you feed a tiny little bit after the summer trim, but they will do fine also without.
I don't know what varieties you have but, I think a good average strategy is to cut them back quite a bit, say to the first greenish segment above the woody-ish bit (you leave that segment whole, and cut just abve the first green node), bring them to a half shady place, water them and feed them. This should encourage both the vigurous and the less vigurous without taking too many risks.
For the future, long growing, leggy varieties (like "Attar of Roses"), if healthy, can be cut down to short stocky stumps in March, and will sprout out in lovely thick bushes. The dwarfer kinds (like "Islington Peppermint") need a somewhat more sensible trimming.