Pruning herbs spurs new growth
Q. Someone was talking about pruning in the herb garden. Is this a thing? If so, what should I be doing?
Mary from Canfield
A. Yes, pruning is a thing in the herb garden. It is a great tool to keep your perennial herbs looking fresh.
Pruning perennial herbs is best left until spring now that the coldest days of winter are here. When new growth begins at the base of woody stems, it is time to prune. Anything without new growth should be removed first, followed by stems with few or limited sprouts.
Pruning is good for the plant and necessary for its health and well-being. Pruning clears out dead wood, making room for the new growth. Oregano is a good example.
Pruning out dead stalks encourages the oregano to begin growing, focusing on new growth. Eliminating the struggle for space to expand allows the plant to put all of its energy into growing. The act helps shape the plant. Think of pruning as directing the plant to grow based on the buds/growth you are leaving behind. The direction they are pointing in is the direction the plant will grow. Many gardeners see pruning as a difficult process. Know that the end results are worth the effort.
Herbs do best when they are used. As they are used, pruning naturally takes place through the spring, summer and fall. Thus, be sure to make pruning cuts back to another growing point – not just cutting off random sized pieces to use. Selective pruning encourages the plant to continue producing. You are praising and approving the plant, letting the plant know it is doing the right thing.
When spring does arrive, a walk through your garden will help you identify plants that are ready for some attention. Sweet marjoram, mints, catmint, catnip and any of the balms – lemon, lime or variegated – are easy starting points. They will show new shoots at ground level. This is the time to clean these plants up by cutting back all the dead stems and old growth. Otherwise, by mid-April they will be beyond gentle pruning.
With thyme, you should leave 2-inch stalks. As the plant begins to grow from the center out, these stalks can be removed. Otherwise, the plant will have a woody center – an ugly sight in a greening herb garden.
Plants to leave alone until late spring are lavender, sage, Lady’s Mantle, rue and artemesia. Lavender grows from the inside out like thyme. When new growth is seen, the stalks should be cut back to the new growth, leaving a half-inch of old stalk so as not to disturb the new growth. Without pruning the lavender grows, but will eventually look like a mound of small palm trees. Not pruning means that your lavender will not continue to produce flowers and renew itself each year.
Eric Barrett is OSU Extension educator for agriculture and natural resources in Mahoning County. Winter hours for the Plant and Pest Diagnostic Clinic vary. Submit questions to the clinic at 330-533-5538 or drop samples off to the OSU Extension Office in Canfield.