Question
I have a caryopteris divaricata which has grown far too large for the space it's in.  Can it be divided?  If so, when. I live in an area which has quite cold winters (zone 5 to 6).  We frequently have temperatures if below 0 degrees Fahrenheit.  Can you please advise?  Nobody here seems to have a good answer as it's a fairly unusual plant for this area.
Thanks, Kathy

Answer
Hello Kathy

Thank you for your question.

Yes, your Caryopteris divaricata can be divided!  The best time to do so is when the plant is in its dormant period, (when all the top growth has died down).  The best times are, say, from the end of September/mid October or end April/beginning May.

To divide the plant first cut down all the dead growth and dig up the root-ball!  You may be able to divide it into 2, 3 or even 4 pieces, depending on how big it is.

Once you have the root-ball out of the ground get 2 garden forks and stick them back to back and touching down through the middle of the root stock and prise them apart to make 2 plants (in fact do this as many times as you can to get more plants to spread around!)

Replant each piece of root-ball immediately in its new home (mixing a general granular fertilizer with the soil from the hole), firm in and water well to settle the soil.

This plant is generally frost hardy, but if the winter temperature in your area goes down well below zero, try to plant it near a south facing wall or hedge and cover the crown with a mulch in the winter.

I hope this advice helps!