Seeds or Plants?
Question: I am confused about which herbs I can grow from seeds, and which ones I should buy as plants. When is one way better than the other?
Herbs are such diverse plants that there is no simple answer. As a general rule, herbs classified as annuals, hardy annuals or biennials are good candidates for starting from seed. Basil, borage, cilantro, dill, German chamomile, marjoram, parsley, and summer savory are the most popular herbs in this group. In true annual style, these plants complete their life cycle — from seed to plant and back to seed again — in less than a year.
We sometimes think of annuals as inferior to perennials because they live for such a short time, but in fact they should be admired for their ability to pass down their genes from generation to generation, ingeniously packaged as dormant seeds. Annuals that quickly produce lots of seeds often are quite successful in nature and their speedy growth makes them popular among gardeners, too. However, it is important to start with good seed. Usually the best seed is gathered by an herb gardener who knows what he or she is doing, or sold by a reputable company in packets dated for the current year.
You can buy seedlings of annual herbs, which saves you the time and trouble of growing them yourself. However, growing your own seedlings makes it possible to have varieties — globe basil or Italian parsley, for ex- ample — that often are not available as seedlings, but are easily purchased as seed. Growing your own guarantees that you will have young, vigorous seedlings that haven’t been stressed by chilling, dry conditions, or crowded roots – common hazards for plants kept on store shelves. When subjected to any type of stress, cilantro and dill often switch from growing leaves to making flowers before you can get them planted.
Starting seeds is also less expensive than buying plants, which is important if you want a large number of plants, for example fifty specimens of sweet Annie (Artemisia annua), a wonderful annual herb for crafting into wreaths. Don’t worry if you only use some of the seeds in a packet, because most herb seeds are good for at least a couple of years when stored in a cool, dry place.
Many perennial herbs can be started from seed, too, and you may have to start with seeds if you want to grow lesser-known medicinal herbs like cough root (Lomatium) or senega (Polygala). Perennial plants usually grow more slowly than annuals, and many make no attempt to bloom — much less produce seeds — until they are at least two years old. Then, when they finally do produce seeds, it is quite common for the next generation to vary a little from the mother plant.
This is no big deal if you want the herb in its ancestral form, or if the plain species is all that is available, as is the case with mountain mint and many other herbs. However, improved or distinctive forms of many perennial herbs are available, and rather than risk losing the characteristics that make them special, these plants are propagated vegetatively rather than by seed. Vegetative propagation ensures consistency of flavor, fragrance, medicinal potency, leaf variegation, growth habit and other characteristics from one generation to the next.
This is why many fine herbs are available only as plants. A huge assortment of unique mints, lavenders, sages and thymes are always sold as vegetatively propagated plants, as are dozens of scented geraniums. Most perennial herbs that have earned a variety name, such as flavorful ‘Kaliteri’ Greek oregano and cold-hardy ‘Arp’ rosemary, are sold exclusively as plants.
Buying plants can be a time-saving convenience, or it can be a necessity if you are to get the best possible strain of many herbs. Yet there is also much satisfaction in starting herbs from seed, which is the only way you may ever get to know dwarf ‘Fernleaf’ dill or ‘Sweet Salad’ basil. As you plan for the gardening season ahead, invest your dollars in high quality vegetatively propagated perennial plants, and devote your time to growing distinctive annual herbs from seed.
Barbara Pleasant is a contributing editor to The Herb Companion and author of several books about gardening, including The Whole Herb (Square One, 2004).