Whether sage, rosemary or basil: these frost-hardy garden herbs provide aromatic seasoning for the kitchen even in the cold season.
Those who rely on frost-hardy garden herbs do not have to do without fresh herbs in the kitchen in winter. Yet few people know that even Mediterranean herbs such as sage, rosemary or the evergreen olive herb can be harvested in winter. Even if the leaves are then not quite as aromatic as in summer and contain a little more bitter tannins, they always taste better than dried spices. Planted out in a bed with water-permeable, sandy-loamy soil, other perennial species, such as curry herb or Cretan dittany, can also survive temperatures as low as -12 °C / 10 °F.
How to plant frost-hardy garden herbs
As frost-hardy as some garden herbs are: To get through the winter well in temperate climate, you should choose a sheltered location for the plants in the garden from the outset and ensure well-drained soil so that no moisture can collect in it. Parsley can be sown directly into the bed as early as March, but if you want to harvest the garden herbs even in winter, wait until the end of July. Winter-hardy sage species such as Spanish sage, which is considered even more digestible than common sage, can be planted from spring to fall. The recommended planting distance is 40 centimeters (16 inches). Thyme is planted in the spring.
If you cultivate garden herbs on the windowsill, there are many more species that can be harvested in winter. Cress and chervil, lemon balm, tarragon, lavender and chives, but also the popular basil reliably provide fresh leaves here. Indoors, seeds can also be sown and planted year-round, if you have the foresight to obtain seeds at the beginning of the gardening season, have obtained seedlings by propagation, or have taken the plants out of the bed in the fall. After all, they are often difficult to find in stores in the fall and winter. Use potting compost or nutrient-poor and very well-drained substrate, which can be mixed with sand. A bright location without direct sunlight, which can quickly lead to sunburn, especially at the window, is well suited for the garden herbs.
Owners of a cold frame can still sow winter purslane or spoonwort in the summer. If you close the flap in the fall, the garden herbs will continue to grow protected and can be used fresh for cooking in the winter.
How to care for frost-hardy garden herbs
Evergreen herbs in particular, such as bay laurel, should continue to be watered in sunny weather during the winter months. Often garden herbs suffer more from drought than from frost. Even the wood of heat-loving exotics such as fruit sage, lemon verbena and basil will not take damage until -3 °C / 26 °F. However, because the leaves already freeze at 0° C / 32 °F, bring them indoors in time.
Herbs on the balcony and terrace are much more exposed to the cold than plants in the bed. Especially the sensitive roots must be protected. Smaller balcony boxes in particular often freeze through within a short time. This can be prevented by placing them in a second, larger box and then stuffing the resulting space with dry autumn leaves, chopped straw or bark mulch.
Wrap larger planters with reed or coconut matting and place them on Styrofoam or wooden boards. To ensure that thyme, hyssop and mountain savory that overwinter in the bed can be used for as long as possible, cover the soil around the shrubs with a hand-high layer of mulch or compost from leaves. Herbs that were not planted until fall can “freeze up” in a frost. So check on the newcomers from time to time and press the root ball firmly into the soil as soon as the ground is no longer frozen.