continued Some shrubs also need haircuts to keep their shape or health and to stay within bounds. Spirea, potentilla, barberry are three that appreciate a fall trim. Even lavender, which is very hardy in the varieties of ‘Munstead’ (light purple) and ‘Hidcote’ (dark purple) is best treated this way.
If a perennial has woody stems and is semi-persistent (called a sub-shrub) use this treatment. After the blooms of spring, I trim spirea to my knees and some bloom again. All the others in this group get their knee high trim in fall, but every three years I will cut them to the ground.
Down under all the twiggy tangled growth of the past seasons there is built up dead useless material impossible to unravel.
Usually, the plant has suckered, with long stems taking root and spreading beyond its boundaries. Now, using shovel and lopper, cut back the errant roots and shoots. New growth quickly sprouts in spring and if I took care to put the spirea first on my list in August, probably all will bloom. Yes, my knees are shorter than most, but cut back by half, at least.
In Cazenovia, butterfly bush or buddlia, in their many colors can reach five feet or more by August, blooming for months, only needing a trim of finished spikes throughout. At the end of the season, a pair of loppers are needed to cut them to the ground.
Again, no stubs! Late to wake up, many fear they’ve been lost to our winters, but wait until Memorial Day or longer before digging up the body, please.
New growth will come from the roots. If this cutting down is saved for a spring chore, the weight of our snow will split open the long stems and wet and rot may kill the roots. Please do the same for white ‘Annabelle’ hydrangeas.