By Denise Seghesio Levine, U.C. Master Gardener of Napa County
To pinch or not to pinch? That is the question. Pinching is a technique that can shape a plant; increase production of herbs, flowers and fruits; determine the size of blooms and fruit and even keep your garden blooming longer. But pinching is not the answer for every plant. So which plants should you pinch, and how?
Pinching is a form of pruning. You can do it with no other tool than your fingertips and fingernails, although if you have a lot of pinching to do, clean scissors or shears will save your manicure. By “pinching,” I mean actually removing the new tender growth at the end of a stem.
Pinch as close to leaf nodes as possible, being careful not to injure the tiny buds beneath. Each time you remove a main stem, your plant will try to grow two new stems beneath the pinch or cut. This easy technique encourages fullness and also helps keep plant size in check. It forces most plants to grow bushier and fuller rather than concentrating their energy on getting taller.
Basil, tarragon, thyme, sage, scented geraniums and marigolds respond well to pinching. Oregano and thyme do best when pinched or cut back to about half their length. Frequent pinching can keep rosemary and lavender to a manageable size during their spring growth spurt and supply you with lots of herbs for cooking. Cut back woody stems by no more than one-third.
With most herbs, the more you pinch, the more you will have. For a summer-long harvest of Genovese or Thai basil, pinch.
Inspect the base of the leaves where they connect to the stem and you will see new leaves forming in tiny pairs. Pinch right above that point and soon each pair of leaves will turn into a new branch. This practice keeps your plant producing leaves rather than going into flower and seed mode. Remember to feed your culinary herbs and keep them watered so they will work hard for you.
Many flowers benefit from pinching or cutting, rewarding you with armloads of blooms. But it's worth getting to know the few flowers that do not like this treatment because an unwelcome pinch can eliminate your entire harvest for the season. Do not pinch campanula, cockscomb, delphinium, dill, stock, larkspur and most sunflowers.
Do pinch annuals such as coleus, impatiens, salvia, most snapdragons and petunias early in the season to encourage bushing and spreading. Pinching encourages more side branches, which means more flowers and color for your garden or pots.
Always pinch at a node but decide how low to pinch depending on how compact you want the plant to be. Sweet peas will branch into a much fuller plant with pinching. When you are happy with your plants' shape, stop pinching and let them grow.
Zinnias and cosmos are especially generous bloomers if pinched. Pinch early to promote branching, then “pinch” by cutting flowers. The more frequently you pick bouquets, the more flowers you will have for your tables and your friends. It is a beautiful thing.
Each time you pinch a plant, you delay its flowering. The result is a plant with more side shoots but smaller flowers. With chrysanthemums you can decide if you want a few large flowers or many smaller ones. If you prefer dinner plate-size blossoms, remove side shoots and laterals early in the season when they are green and succulent, leaving only the few stems you want to bloom.
You can stagger bloom times with some late-flowering plants like Russian sage, phlox and asters by pinching back half of the plants in your flower bed by about one third. The pinched plants will bloom later, giving you a few more weeks of summer beauty.
Remove peony blossoms when they are finished so the plant can focus energy on next year's blossoms instead of producing seed. Clip foxglove after blooming to have healthy flowers next year or forego pinching them and let them self-seed. You will probably have fewer blossoms next year but potentially more plants.
Refrain from pinching if you want blossoms and seeds for local birds and insects. As a compromise position, let the last, late blooms go to seed, or identify a few plants as your seed producers for pollinators, birds and self-seeding.
Workshop: U. C. Master Gardeners of Napa County will conduct a workshop on “Make Room for Salvias” on Saturday, April 21, from 9:30 a.m. to 11:30 a.m., at the University of California Cooperative Extension office, 1710 Soscol Avenue, Napa. Every gardener should be able to find a salvia just right for that little (or big) space. Salvias are long-lasting, attract butterflies and pollinators and have attractive foliage. Learn how to select and care for these versatile plants.Online registration (credit card only);Mail-in/Walk-in registration (cash or check only)
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.