Mediterranean herbs (rosemary, sages, thyme, lavender, etc.) are very well-suited to our hot, arid climate. In fact, they’re so well-suited that many perennial types often overgrow their spots and outlast their most attractive, productive years. These drought and heat-tolerant staples of a dry landscape are considered easy care plants, but easy care does not mean a complete lack of care. Here are a few tips on keeping your herbs in good shape.
The soil in the Mediterranean climate zones tends to be stony and somewhat sandy and therefore well-draining. Rainfall amounts are light and limited mostly to the winter months. Vegetation can be sparse so that there is little buildup of humus or decaying plant material which provides nutrients. The most common causes of problems with our landscape herbs are over watering and over fertilization. Feed the tender-leafed annual or biannual culinary herbs such as basil, coriander, chamomile, and tarragon monthly with a low-nitrogen fertilizer (organic – you’ll be eating the leaves) and pinch off flower heads as soon as they appear to keep the plants from setting seed and to maintain size.
Drought-tolerant herbs should be grouped together in irrigation zones so that individual timers can be adjusted to provide just enough water to keep the soil moist at a depth of five or six inches. Newly planted herbs will need consistently moist, not wet soil for the first year or two until root systems are established.
Lavenders, rosemary and many of the ornamental sages are among the herbs that need annual pruning and shaping. Even with regular shaping, the plants become woody and rangy and should be replaced every two or three years. In spring, snip or shear off spent lavender flowers at the base of the main stem; try not to cut into the woodier stem and leaf portions of the plants. Ornamental sages should be cut back to eight to 12 inches in late spring and woody stems should be removed at the base throughout the long growing season. Prostrate rosemary is a great ground cover; upright rosemary is easier to shape and can be kept in a pot for culinary use.
Herbs kept in pots can outgrow the pot within a year. Plan on replacing oregano, marjoram, culinary sages, and rosemary every other year. Or buy bigger pots.
Harvest sprigs and leaves (with the edible flowers attached) of organically fed culinary herbs and flowering lavenders in spring when volatile oils are at their highest levels. Dry them in a single layer on newspapers outdoors.
Plant exchange is Saturday
Fresno’s annual water-wise plant exchange will take place Saturday from 8 a.m. to noon at the Fresno State Horticulture Greenhouse Park, 3150 E. Barstow Ave. Admission is free.
Visitors will receive “something special” if they bring water-wise plants, cuttings, bulb seeds, shrubs or trees to share with others at the free plant tables.
There is a long list of exhibitors offering free plants and advice on water-wise plants and irrigation techniques. Bring your old garden books for a Garden Book Exchange and tour the John Weiler Memorial Iris Garden and the Water-Wise garden. Workshops given by experts on water-wise plants begin at 9 a.m..
Bring a small cart or wagon to carry your water-wise plant trophies back to your car.
Elinor Teague: firstname.lastname@example.org