When can I chop and split my phlox?
Q As my phlox plants have grown quite tall, can I give them a trim and can I divide them for more plants? Also, do foxgloves self-seed?
Alan Redfearn (via email)
A By all means shorten your phlox plants by half if shoots are tall and wispy, and bending over. This will cause side-shoots to form and they should flower later in the summer.
Autumn is the best time to divide your phlox, when leaves are withering and plants are becoming dormant.
Reduce them to within 6in (15cm) from the base and split clumps into chunky well-rooted portions. It can be done now if absolutely necessary, but plants would be stressed as they are still growing and flowering and take longer to recover.
As for foxgloves, leave seed vessels to turn brown and start to split. Then, before seeds are dispersed, collect them and sow them thinly in pots or seed trays of gritty compost and water them in. There is no need to consign them to your greenhouse.
Seedlings will appear within a few weeks. Transplant them into their flowering positions in October.
Patience with a tree peony
Three years
