Fall or spring for herbs?

Typically, spring is the season we associate with planting and growth. This is true for seed and annual gardening, but fall is the time I recommend for hardy perennial herb plants. These are the herbs that survive for many seasons as opposed to annuals, which must be planted each year or sometimes reseed themselves.

There are two reservations I want to convey. One is that the plants should be sturdy perennials with a defined root system. This will guarantee that the rains will be poured into exploding underground growth during the winter, and burst forth above ground come spring. The second concern is that the young plants may need winter protection at higher elevations and in cases of severe weather. This means days of icy cold and wind. Snow, on the other hand, insulates plants so that growth continues under its cozy blanket. This will not be so hard to picture if you think of Eskimos in their “toasty warm ice houses”!

I use straw and hay to cover young plants when caustic weather is forecast. This works well to protect tender perennial herbs, which are vulnerable to frost damage, as well as newly planted hardy varieties. You can also use a glass or plastic cloche (see photo) which allows light to enter. It must be propped up for ventilation on warmer days. Clear plastic containers may be utilized as long as there are holes for air circulation.

I have used a variety of protection devices over the years including buildings, neighboring plants, rocks and garden accessories. They can shield strategically placed “tender plants” from wind and cold. A cold frame is a must for potted “tender herbs” which will not survive the winter. This is where I keep my aloe, angelica, and lemon grass (see photo) until it is warm enough to free them. Location is often the reason your next door neighbor can grow lemon verbena and pineapple sage as a perennial, and yours dies. Planting them in a protected site that warms early in the spring and cools late in the fall will help, but there is no guarantee.

Early fall is when I add compost at the base of herbs that have visibly depleted soil. Perennial herbs are not heavy feeders and have better flavor if made to struggle so I do not generally fertilize. If the plant is doing well and the ground around it is plump I do not disturb the “happy fella”.

Each plant, whether it is one I have divided or purchased, is thoroughly watered before put in the ground. The hole should be twice as deep and wide as the root system. Tease out the roots around the sides and base of the plants. A wire basket is a must if gophers are a concern! The crown of the plant should be level with the surrounding soil when first planted. It will settle in time providing a receptacle for water.

If you are planning a “bed of herbs” I suggest you dig the planting layer out to about a foot. Lay small holed chicken wire on the bottom if it is necessary to fend off gophers. This is a good time to enrich and adjust the neutrality of the soil (most herbs prefer a pH of 6.5 - 7). They will however, tolerate most soils as long as there is good drainage and six to eight hours of sun each day! For initial planting soil I suggest the ratio be 2 parts topsoil, 1 part garden sand and 1 part compost. This is the ideal time to think about a raised bed, which is easier to maintain and can be as high as you like.

I spring for fall when it comes to planting hardy perennial herbs such as lavender, thyme, winter savory, hyssop, artemisia, rosemary, sage, southernwood, germander, yarrow, oregano, lemon balm and santolina. The less hardy perennials such as parsley, chives, mint, and costmary also do well, but these youngsters will need more protection. Tender herbs such as basil, coriander, fennel, French tarragon, and anise are best planted in the spring when frost is past.

Keep in mind gardeners, that digging in soil softened by fall rain sure beats struggling with the rigid ground of summer and spring! It is also the “water wise” time! Less water is required when the soil is blessed by an occasional heavenly drink and does not contend with hot winds and weather.

This column is in response to a reader’s request. Please send your “herb topic” suggestions to me at [email protected]. Check my website at herbbasket.net for garden information, and happenings.

A special thanks to my husband Mike (Cummings Valley Graphics), who provides the photos taken from our garden each month!