Dennis Patton’s tip this week: I must admit I am enjoying my perennial garden this spring. The cooler temperatures have meant some flowers are lasting longer, and timely rains have kept the need to water at bay. Now if I could just find someone to help pay for my mulching addiction, life would be almost perfect in the garden. But as I have been working through the beds I have noticed one chore yet to be completed on my checklist — pinching perennials.
Pinching is the removal of the growing point of the stem, resulting in a development of side shoots. Pinching or cutting back perennials is a task that will result in a nicer appearance in the garden. A plant that has been pinched often is short, stockier and less likely to flop over in the garden. The most common plant pinched or cut back is the garden mum, but other plants respond well to this treatment.
Many plants will produce one long shoot ending in a flower later in the season. By pinching or cutting back, that one shoot can be turned into two, three or even four or more shoots, each ending in a flower. Some plants should only be cut back once, while others can be pinched a couple of times. The classic example is garden mums. For example, when the mum reaches about 6 inches high cut back to about 3 inches. A few weeks later, when the plant reaches 6 to 8 inches again, cut it back to 4 or so inches. This process can be repeated until July 1. Growth produced after this period of time will need to develop for fall flowering. Fall asters can also be treated this way.
There are several other garden perennials that benefit from a onetime pinching or cutting back. Cutting them back by about half will reduce the height of the plant, which in turn helps to develop a shorter, stockier plant. The result is a more manageable plant which stands up and produces a plethora of flowers. It also reduces the need for staking, which is cumbersome and hard to do.
Perennials that respond well to pinching include:
Sedum (Autumn Joy)
Platycoden (Balloon Flower)
Eupitorum (Joe Pye Weed)
Pinching can be done one stem at a time, or for thick plants a pair of hedge shears may work. I know the hedge shears work great on my large clump of mums, making it short work. Hand-pruning one at a time does leave the plant in better condition, as the placement of the cut can be controlled. Though in some ways, whether you selectively cut or just whack it back, it’s akin to a bad haircut; give it a couple of weeks to grow out and all is forgiven. Ideally you would make the cut just above a leaf. The new shoots will develop from the axial of the leaves. This happens as the dominance of the stem is transferred to many dormant buds in the plant.
Give it a try and hopefully you will find your garden a little more manageable this season. I know in my garden these taller plants are more manageable after getting a trim. Guess I have another chore to add to my to-do list as I spend a few more quality hours out in the garden.