Basil and other herbs are wonderful additions to the garden even if you never use them in cooking. They add a variety of textures and scents, and their flowers will draw flocks of butterflies and bees. But regular pruning and pinching will give them a nicer shape and a fuller habit, and once you start nibbling and experimenting with what you’ve pinched, you’ll appreciate your herbs all the more!
Plants that are not pinched back will start blooming. Once herb plants produce flower buds, the flavor of the leaves gets bitter. If you’re growing Thai basil simply because you love the big heads of purple flowers, or if you’re growing 'Lime' basil for its wonderful aroma alone, then flowers are fine. But if you want to use your herbs in the kitchen, it’s important to keep them from flowering.
When you harvest your herbs, don’t be shy. Your goal is to prune back the stems, not just to pick off individual leaves. Herbs are very forgiving, and as long as you don’t pinch them right down to the ground, you really can’t pinch them too much or too often. Pinching herbs is not a delicate art!
Pruning herbs doesn’t require special tools. You can pinch herbs with your fingers, using your thumbnail and fingernail to cut through the stem. Pinching basil can put a startlingly dark stain on your fingertips. My nails are a lost cause during summer gardening anyway, but you might want to use scissors to snip the stems.
Count up one or two pairs of leaves from a branch point...
and then pinch or snip away the stem above.
For basil, the idea is to leave one or two pairs of leaves per branch. If you look at the base of the leaves where they meet the stem, you will see tiny pairs of new leaves forming. When you pinch through the stem just above this point, each pair of leaves will soon turn into a new branch. When that new branch has two or three sets of new leaves, pinch it again. The plant will get bushier with each pinching, and you’ll get a larger harvest each time. By the end of the season, you could be picking enough basil for a batch of delicious pesto from just one or two plants.
Soon there will be 4 stems to pinch
If your basil plants are leggy and blooming now, does that mean you’ve missed your chance at a tasty harvest? Not at all! Prune the plants back hard, so just one set of leaves remains above the major branch points. The plant will produce new growth, and the flavor of the leaves on the new branches will be perfect. There’s no need to harvest the leaves when they are tiny, either. Baby spinach leaves may be a delicacy, but larger basil leaves have wonderful flavor as long as the plant is not allowed to bloom. And letting the leaves get larger means you’ll have that much more fresh basil to enjoy.
Pinching to control flowering is also useful if you plan to save seeds. Basil often comes true for me from saved seeds regardless, but cross-pollination can happen if you’re growing more than one variety. You can isolate varieties by planting them on opposite sides of your garden. Or, you can isolate the blooms in time by letting only one variety of basil bloom and keeping the others pinched back. Basil seeds seem to take anywhere from four to eight weeks to mature on my plants. I often start letting a few plants bloom in mid-August to be sure of harvesting seeds before frost turns the plants to black mush. I might even allow just one or two branches to set seed and continue to pinch and harvest from other branches. I’ve heard that permitting any blooms can make the entire plant taste bitter, but to me any new growth tastes delicious no matter what the rest of the plant is doing.
Basil is not the only herb that benefits from regular pinching. The same principles apply to other herbs in your garden, whether thyme or oregano, lavender or rosemary, pineapple sage or rose-scented geranium. Stems of thyme and oregano should be cut back by no more than half their length, and the woodier stems of rosemary and sage should be cut back by no more than one third. As with basil, you will see tiny new leaves forming next to the stem, waiting to form new branches when the plants are pinched back. The more you pinch, the more your herbs will grow!
Pinching and harvesting of perennial herbs should stop at least two weeks before you might expect cold weather. Newly cut stems and tiny new leaves are vulnerable to frost damage, and you want to give your herbs a chance to harden up a bit before winter.
So start pinching with abandon, and get the most out of your herbs this summer!
Nearly everything I know about herbs I learned from Tom DeBaggio, in particular from his little book, Growing Herbs from Seed, Cutting and Root: An Adventure in Small Miracles. See this Garden Bookworm entry.
Don't miss the other articles in this series.
(Editor's Note: This article was originally published on August 21, 2007. Your comments are welcome, but please be aware that authors of previously published articles may not be able to respond to your questions.)