Herbs make great additions to a school garden. They can be grown in a bed of their own or intermingled among vegetable plants, and many are good choices for container growing. They offer a harvest of interesting tastes, fragrances, and textures, along with a wide array of curriculum connection possibilities. Herbs have many historical ties and have been used for centuries for healing, personal care, and dye making, as well as to season foods. There is a lot for students to explore about the history, use, and sensory attributes of the herbs they grow.
Herbs plants can be divided into two main categories: annuals (or plants grown as annuals), which complete their life cycle in one growing season, and perennials, plants that live for three growing seasons or more. Here are our suggestions for six easy-to-grow herbs to get you started on the adventure of herb growing.
Basil This herb should be high on just about every kid’s list, for what would pizza be without it? It also offers a lot of variety, from classic ‘Genovese’ basil with its large, dark green leaves to beautiful, deep purple ‘Opal’ basil to spicy Thai basil that enhances Asian dishes. Explore different tastes with anise, lemon, cinnamon, and lime basil varieties. For container growing try compact, tiny leaved ‘Spicy Globe’ basil that gets only 6-9 inches tall.
Basil is easy to start from seed. A warmth lover, its seeds can be planted directly in the garden once the soil is warm and the weather settled, about 2 weeks after the last spring frost date. Or seeds can be started indoors 4 weeks before the last frost date; set the hardened off seedling out in the garden 2 weeks after the last frost date. Choose a spot in full sun with fertile, well-drained soil. Sow seeds 1-inch apart and ¼-inch deep. When plants are several inches tall, thin to 8 inches apart. Set out started plants 8 inches apart.
When plants are 6-8 inches tall, pinch back the main stem by about half, just above a set of leaves. This will encourage the plants to form lots of new stems. Pinch back these new stems similarly and pinch off any flower buds you see forming so the plants will produce dense, bushy growth with lots of new leaves. To harvest, pinch or cut off young leaves. Make several plantings throughout the growing season for a continuous harvest.
Dill The feathery leaves of dill add a piquant flavor to many dishes. If you let the plants blossom and set seed, the umbrella-shaped flower heads will attract beneficial insects to the garden, while the seeds are a must for flavoring dill pickles and dilly beans. Dill plants are relatively tall (3 feet) and spindly. For container growing look for dwarf varieties such as ‘Fernleaf’ and ‘Ella’.
Dill doesn’t transplant easily so it’s best to sow seeds directly in the garden after the danger of frost is past in spring. Choose a spot that gets full sun. Sow seeds ¼-inch deep and 1-2 inches apart. When plants are a few inches high, thin to 4 inches apart. Make successive sowings every 2-3 weeks until about 8 weeks before your fall frost date for fresh leaves to harvest all season long. If planted in relatively fertile soil in a garden bed, you probably won’t need to give dill plants any additional fertilizer. If you’re growing in containers, feed with a half-strength soluble fertilizer monthly.
If you find green caterpillars accented with yellow, black, and white feeding on your dill, these are the larvae of black swallowtail butterflies. The caterpillars, also known as parsleyworms, may dine on other Carrot family members, including parsley, carrot tops, fennel, and wild Queen Anne’s. Plant a small patch of dill or parsley away from your main crop and you can relocate caterpillars as necessary and enjoy the sight of beautiful butterflies flitting about your garden.
Harvest the fresh leaves of dill any time before flowers begin to form. To harvest the seeds, clip off the entire flower head 2-3 weeks after the blossoms appear and put it in a paper bag. Place the bag in a dry, well-ventilated spot until the seeds dry and fall from the head.
Parsley While it may be most familiar as a garnish, parsley offers lots in the way of nutrition. It’s a good source of vitamins A, C and K, as well as folate and healthful antioxidants. So it makes a great addition to all sorts of salads, dips, and soups – even smoothies! Botanically speaking, parsley is a biennial – a plant with a two-year life cycle. The first year it produces just leaves; the second growing season it flowers and sets seed. But because we’re harvesting the leaves, and once flowers appear, the leaves become bitter, we grow parsley as an annual. It also doesn’t survive the winter in many parts of the country.
There are two types of parsley – curly leaved, commonly used for garnishes, and flat-leaved or Italian parsley, favored for cooking because of its flavor. Because it’s a relatively slow grower, it’s best to either start parsley early indoors or purchase started plants from a local nursery. Seeds germinate slowly, taking 3 weeks or longer. Soak seeds in water overnight before planting for the quickest germination. Sow seeds in individual pots in plantable containers, such as peat pots, to avoid disturbing roots at planting time. Hardened-off seedlings can go out in the garden as early as 1-2 weeks before the last spring frost date, spaced 10-12 inches apart.
To help black swallowtail butterflies, plant some extra plants to feed any parsleyworms that appear, or move these caterpillars to wild Queen Anne’s lace plants outside the garden.
To harvest parsley, cut off individual stalks close to the ground, starting with the outer stalks. This will keep plants more productive than snipping off just the tops of the leaf stalks.
Chives This onion relation is one of the prettiest herbs you can grow, sporting small domes of lavender flower clusters atop hollow, mildly onion-flavored stalks. Plus, once you’ve planted this sturdy, trouble-free herb, it will come back for many years and is easy to divide and make more plants. In fact, to keep your chive plants growing vigorously, you’ll need to divide each clump every 3-4 years, giving you plenty of material for replanting, if you choose.
While you can grow chives from seed, it’s is easiest to begin with started plants, which are actually clumps of individual seedlings. Set them out in the garden 8-12 inches apart as soon as the danger of frost is past in spring.
Harvest chives by cutting off the leaves with a pair of scissors a couple of inches above the ground. You can cut a few leaves from each of several clumps to keep them all producing or cut all the leaves from one clump, then let them regrow. Chive flowers are also edible and have a mild onion flavor. Sprinkle some on a salad as an eye-catching garnish. Cut off flower stalks at the soil line after they have finished blooming. Stop harvesting from plants about 3 weeks before your fall frost date to allow them to get ready for cold weather. Chives are very winter hardy; at least to Zone 3.
Mint If you like variety, you’ll love mints! You can choose from peppermint, spearmint, pineapple mint, chocolate mint, apple mint, orange mint, and more! While these mints each have a distinctive flavor and scent, they all have one trait in common – a robust, rampant growth habit that can take over your garden if you’re not careful. This makes mints good candidates for container growing, which keeps their vigorous underground runners under control. If you decide to plant mint in an in-ground bed, stay vigilant to keep plants from spreading excessively. One strategy is to cut the bottom off a 5 gallon bucket and sink it in the soil, leaving the top several inches protruding above ground. Fill the bottomless pot with soil and plant your mint plant within the buried bucket.
Begin your mint gardening with started plants. Plants will do well in full sun or part shade and moist, fertile soil. Regularly pinch off the tips of the stems to encourage bushy growth. To harvest, pinch or cut off leaves. Mints are perennials that will thrive for years, but do best if divided every 3-4 years. Most mints are winter hardy to at least Zone 5.
Thyme This low-growing herb can be grown from seed or you can start with purchased plants. There are a number of varieties to choose from, including lemon thyme, German winter thyme, and orange thyme that are excellent culinary herbs, as well as ornamental varieties such as woolly thyme that are used as ground covers.
Start seeds early indoors 6-8 weeks before your last spring frost date. Scatter seeds on top of the germination mix, covering them very lightly with additional mix. Keep moist until seeds sprout, which can take as long as 2-4 weeks. When seedlings have a couple of sets of leaves, transplant to small individual pots for growing on. You can set hardened off seedlings or purchased plants out in the garden after the last frost date, spacing plants 8-12 inches apart. Plants will do best in full sun and light, sandy soil with excellent drainage.
Harvest plants just before the flowers begin to open, cutting stems back to about 2 inches above the ground. You can cut back the entire plant if you want to harvest lots of leaves for drying, or you can cut just a few stems selectively for a smaller harvest at any one time. Stop harvesting about a month before your fall frost date to allow plants to harden up in preparation for winter’s cold. While winter hardiness varies with the variety, most are hardy at least to Zone 5. A winter mulch is helpful in colder zones.
Cut back established plants by about a third in spring after you see new growth starting to keep them vigorous and bushy. (Don’t cut back below where you see new growth coming in, as these won’t resprout.)