Culinary herbs and aromatic herbs are best picked and dried for use when they are just coming into full flower, when the buds begin to show color but before the flowers set seed. In May, the oils that give culinary and aromatic herbs their fragrance and taste are at the highest concentration in the leaves and flowers. Herbs picked now will have more flavor and scent, whether they are used fresh, frozen or dried and stored in airtight containers. Most will continue to produce leaves after this early summer cutting, but few will produce flowers later in the season.
▪ Lavender is extremely popular as a landscaping plant; even more so these days since it is a drought-tolerant plant. Some varieties of lavender (Grosso, fernleaf and Spanish lavenders) will produce several flowerings throughout the spring and summer if all the flower heads are cut off before they set seed. Removing the multitude of flower stalks on a lavender plant is easier if you use hedging shears that cut off many stalks at a time. Be careful to cut off only the flower stalks; cutting into the woody tissue below the stalks will deform the natural shape of the plant. Most varieties of lavender will become rangy and straggly-looking after two or three years. Pruning back an overgrown lavender to try to control size and shape can kill it. Plan on replacing lavender every few years if you prefer a more formal-looking, smaller, tidier plant.
▪ Oregano is one of the few herbs that has a stronger aroma and taste when dried. Oregano flowers aren’t particularly attractive, but they are edible, as are most herb flowers. Cut back the long stems on oregano now and dry the stems, leaves and all, hanging them upside down in a dry, cool place for a week or so; or separate the leaves from the stems before drying them on paper towels until they’re nice and crispy — then store the leaves in airtight containers. (Follow the same method for drying all herbs). Oregano and all members of the marjoram herb family have invasive root systems and are best grown in containers.
▪ Basil leaves have much less flavor when dried than when fresh, but dried basil is just fine for cooking in winter when fresh is not easily available. When a basil plant sets flowers, the taste and texture of the leaves change. The leaves develop a strong, rather pungent fragrance and taste and they become tougher. To maintain the purest basil taste and tender leaves, pinch off flower buds as soon as they appear.
▪ Culinary sage leaves and thyme leaves and flowers can be dried and stored now as can parsely, tarragon and rosemary. Ornamental sages (autumn sage, gentian sage, bog sage, etc) have very fragrant leaves, but are not used in cooking. To control size, ornamental sages are cut back to several inches high in late spring.
▪ European bay tree leaves (Laurus nobilis, rather than the California bay, Umbellularis californica) are also at the height of their fragrance now. The strong fragrance of the oils in herb leaves and flower heads can act as an insect repellent. Herbs seldom have pest insect problems. Use only food-safe pesticides on your herbs and only if pest insect infestations are high enough to cause serious damage. Bees love herb flower pollens —spray pesticides when bees are not active.
Send your plant questions to Elinor Teague at firstname.lastname@example.org (“plants” in the subject line).