The best time to plant herbs will depend on the climate and hardiness zone of each region, some herbs require consistent warm temperatures so they are grown as annuals and are planted in the spring. Perennial herbs are much tougher and given the right conditions will come back year after year. Due to their broad culinary and medicinal uses herbs are worth the extra time it takes to locate them properly in the landscape.
Mediterranean herbs such as lavender and rosemary will grow well in many parts of the country. It is important to check the hardiness zone of each variety since plants within the same genus can vary in cold hardiness. Creeping Rosemary, Rosmarinus "Irene" is more tender than upright rosemary, two of hardiest upright varieties are Rosmarinus "Arp" and Rosmarinus "Tuscan Blue". In difficult climates perennial herbs can be grown as annuals and replaced each spring. English Lavender, Lavandula Angustifolia is very cold tolerant while Spanish Lavender, Lavandula Stoechas is only hardy to zone 8 and above. All Mediterranean herbs need good drainage and as much sunlight as possible, fortunately there are herbs like Bee Balm, oregano and mint that will handle more moisture and can grow in partial shade. Perennial herbs can be planted in the spring when the selection is the best, or in the fall where winters are mild. They can also be started from seed but they grow very slow the first year and it is much easier to start with a purchased four inch plant. It makes sense to grow perennial herbs from seed when a sought after plant is not available.
Annual herbs carry out their life cycle in one year so they are usually grown from seed and planted in the spring. In areas with a short growing season the seed can be started indoors in February and planted in the garden when the ground warms up, seed planted too early is subject to rot or cold damage. Annual herbs like basil, calendula, cilantro and nasturtium rarely need a head start and can be planted directly in the garden once the danger of frost has past. Some annual herbs will reseed on their own and continue to provide plants each summer. Borage, Borago Officinalis is a great self seeder with interesting edible blue flowers, the most common use for borage is to candy coat the flowers and use them to decorate cakes and food platters. Pot Marigold, Calendula Officinalis also comes back from seed and is used in cosmetic preparations due to its soothing properties. Herbal flower petals are a great way to add color to food and those with stronger flavors like lavender are great in baked goods or blended into butter. Herb seeds can be harvested and saved for the coming year, make sure they are allowed to mature and dry naturally on the plant. The best way to store seed is in a paper envelope, it will absorb extra moisture and the name of the plant and the date can be printed on the outside.
Herb Garden Structure
Herb gardens are seasonal in nature. One way to create a year round herb garden is to plant low hedges and small evergreen shrubs within and around the herb garden. Make sure hedge plants are very hardy since they will provide structure and dimension during the winter months when annual herbs have died back and perennial plants are not at their best. Good evergreen hedge plants are True Dwarf Boxwood, Buxus Sempervirens "suffruticosa" and Wall Germander, Teucrium Chamaedrys. There are many varieties of Boxwood but few are true dwarfs, make sure to check the scientific name when purchasing it. Germander has tiny glossy evergreen leaves and a natural appeal, purple flower spikes appear in late summer and draw large numbers of Honey Bees to the garden. Structural plants are an important element of the herb garden and define where the annual and perennial herbs will go. Plant shrubs and sub-shrubs in the fall so the roots can become well established before the growing season begins. For color add herbs like Purple Coneflower, Echinacea Purpurea and Yarrow, Achillea Millifolium.