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Harvesting and Storing Herbs

Garden herbs ready for harvest. Garden herbs ready for harvest. (photo by Jessie Keith)

In early fall, fresh herbs are among the abundance of riches available every day in the garden. Snipping savory leaves as needed throughout the summer and early fall is the best way to enjoy them, but with the end of the growing season approaching, the supply of available herbs may well outstrip the immediate demand. Fortunately, there are lots of easy ways to save some of that herbal bounty to brighten up your cooking and home during the cold weather months.

Bringing in the Harvest

Basil Basil is best frozen for winter use. (photo by Jessie Keith)

How and when you harvest herbs depends on the herb variety and the plant parts you want to preserve. Leafy types, like basil, thyme, oregano or parsley, should be harvested just before the plants flower. Snip off one third to one half the length of each stem to keep plants productive until frost and ensure that you have a good supply of leaves to preserve. If you are harvesting edible flowers, like late-blooming lavender or calendula, clip blooms just after they open. To gather seeds, including dill or coriander, wait until after the green stage, as seedheads begin to dry. Placing bags over the seedheads ensures that nothing will be lost and the bags can hold the seeds while they dry. Roots, such as echinacea and horseradish, should be dug and harvested late, after one or two frosts.

The best time for harvesting leaves and flowers is in the morning before the full heat of the day has set in, but after the morning dew has dried. Hosing off the plants the night before guarantees clean leaves, stems, and flowers.

Up in the Air

Lavender flowers are best dried by hanging in a cool, dry place. Lavender flowers are best dried by hanging in a cool, dry place.

Air drying is an easy, time-honored and effective way to preserve many herbs and flowers. Tie up small bunches of stems and leaves and hang them upside down in a cool, airy space. Garages, attic rafters, drying racks or screened porches are good for this purpose. The herbs are dry when the leaves crumble easily. Separate dried leaves from stems of large-leafed varieties, like catnip or lemon balm, and discard stems. To use dried thyme and other small-leafed varieties, simply crumble leaves and stems together.

Leaves can also be placed on towel-lined trays or in wicker baskets and left in cool, well-ventilated places to dry. If dust accumulation is a worry, place the stems and leaves in paper bags with small ventilation holes and set aside.

Drying Equipment

Dill weed Dill weed can be dried for winter and the seed collected and used as a spice. (photo by Jessie Keith)

Herbs, including parsley, can also be dried very quickly in a microwave oven. Drying times depend on the plant variety and the power of the microwave, but Stephen Orr, author of The New American Herbal, suggests testing your oven by starting with a single sprig of a particular herb and microwaving on “high” for 10 seconds. Experiment and adjust timing as you go along. Large quantities of herbs or roots can also be dried in mechanical dehydrators used according to manufacturers’ directions. Generally, roots should be cleaned and cut into small pieces before drying. Electric ovens will also dry herbs, if the ovens can be set low enough—80 to 90 degrees Fahrenheit. Again, experimentation is the key to determining the right time.

Salt of the Earth

Less in fashion than it once was, salting is also a good preservation method for fleshy herbs like basil that sometimes respond poorly to drying. Choose a glass jar and alternate layers of clean, dry leaves with coarse salt, making sure that you top the jar with a salt layer and a tight-fitting lid. The leaves will stay fresh for a minimum of several months.

The Big Chill

Mints retain their flavor beautifully when correctly dried. (Image by Jessie Keith) Mints retain their flavor beautifully when correctly dried. (Image by Jessie Keith)

Herbs destined for use in fall and winter stews and soups can also be frozen in small bunches. Place these in plastic freezer bags or other containers. Use directly from the freezer. Alternately, freeze herbs like rosemary, basil, and oregano in olive oil or water. The easiest way to do this is to use an ice cube tray, placing small amounts of the herb in each cube space. Top up the spaces with olive oil or water and freeze. These cubes can also go directly from freezer to stockpot or sauté pan.

Storage

While frozen herbs will happily spend the winter waiting in the freezer, dried herbs are a different story. No matter which drying method you choose, store the herbs in glass containers, preferably dark-colored, with tightly fitting lids. Keep them out of direct sunlight. Most important of all—use them. Any dried herbs left over by the time the growing season rolls around again should be discarded.

Flowering Shrubs for Fall

Lespedeza thunbergii 'Gibraltar'
The pink flowers of Lespedeza thunbergii ‘Gibraltar’ add welcome color to the late-season landscape.

Late summer and fall is a time when most gardens (and gardeners) could use a bit of a pick-me-up. And no plants are better suited for the job than the relatively few shrubs that flower in the growing season’s waning weeks. Whether used as single specimens to spice up drab niches, or combined with other colorful fall plants (such as autumn crocus, Japanese anemones, beautyberries, goldenrods, and sourwood) in a collective blaze of autumnal glory, fall-blooming shrubs are essential elements of a four-season garden.

Hibiscus syriacus 'Helene'
Hibiscus syriacus ‘Helene’ is one of the prettier varieties of this late-season bloomer.

Quite a few fall-blooming shrubs commence flowering in spring or summer, thus providing multi-season display. Among the longest-blooming of this lot is Daphne × transatlantica. A parent (along with Daphne cneorum) of the much more widely grown Daphne × burkwoodii, this small shrub produces flushes of bloom from mid-spring to fall, long after ‘Carol Mackie’ and other burkwoodii cultivars have ceased flowering. With its clustered, frosty-white, fragrant blooms and dainty, blue-tinged, semi-evergreen leaves, it makes an ideal candidate for a pathside or patio planting. Its variegated cultivar ‘Summer Ice’ has creamy-white leaf margins. Plants are hardy to USDA Hardiness Zone 5, and are best sited where their rather brittle branches will not be subjected to extra-heavy snow loads.

More familiar to gardeners are several other shrubs that flower from summer into early fall. Butterfly bush (Buddleia davidii) produces large candles of fragrant flowers in a range from violet to lilac-pink to white. Butterflies adore them. A somewhat cold-tender shrub, butterfly bush is root-hardy to USDA Zone 5, often dying to the ground in the colder sectors of its hardiness range. Even where it’s reliably root-hardy, it usually benefits from a severe pruning in early spring, growing to several feet tall by midsummer. Many cultivars are available, including the outstanding, compact hybrids ‘Ellen’s Blue’, ‘Blue Chip’, and ‘Ice Chip’. This species seeds itself profusely in warmer areas of its range, where it is sometimes considered a nuisance.

Hydrangea paniculata 'Tardiva'
The large flower panicles of Hydrangea paniculata ‘Tardiva’ are large and upright.

Chaste tree (Vitex agnus-castus), like Buddleia davidii, is a large, fragrant-flowered, butterfly-thronged shrub that usually dies to the ground in the northern fringe of its USDA zone 6 to 9 hardiness range (but attains tree-like proportions in warmer districts). The divided, five-fingered leaves are spicily pungent. Steeples of lilac-blue or white blooms appear from late summer to early fall, on stems that grow to several feet in a single season. Notable cultivars of chaste tree include blue-flowered ‘Shoal Creek’ and white ‘Silver Spire’. Vitex fanciers in USDA zone 5 might want to try chaste tree’s hardier relative, Vitex negundo var. incisa, which has more elegant, finely divided foliage and wispy sprays of lilac-blue flowers.

Rose of Sharon (Hibiscus syricacus) is yet another favorite that flowers from summer into early fall. The large, somewhat floppy blooms bear little resemblance to those of their namesake, nor do their lobed, vaguely maple-like leaves. First introduced to gardens in the sixteenth century (or earlier), this large shrub or small tree has given rise to numerous selections with floral colors ranging from blue to violet to burgundy to pink to white. Among the best are the sterile, white-flowered ‘Helene’ and ‘Diana’, which unlike most other cultivars will not self-sow. Hardy to USDA Zone 5, rose of Sharon will recover quickly and bloom if killed back in a severe winter (or if heavily pruned in early spring).

Buddleja davidii 'Peakeep' (PEACOCK™, ENGLISH BUTTERFLY™ SERIES)
The bright flowers of Buddleja davidii ‘Peakeep’ (PEACOCK™) will bloom until first frost. (photo by Jessie Keith)

The large, white, cylindrical flower clusters of panicle hydrangea (Hydrangea paniculata) typically appear in midsummer. The cultivar ‘Tardiva’, however, comes into bloom weeks later than most other selections, peaking in late summer and early fall. Lacier and more elongated than those of the familiar peegee hydrangea (Hydrangea paniculata ‘Grandiflora’), the flower clusters are especially large and late on plants that receive a severe pruning in early spring (plants grow to 7 feet tall in one season). This rock-hardy large shrub succeeds into USDA Zone 3.

In contrast to the above shrubs, Thunberg’s bush clover (Lespedeza thunbergii) concentrates all its bloom in September and early October, enveloping its arching branches in a lavish, vibrant display of rose-purple flowers. As with many late-blooming ornamental shrubs, it sometimes dies back in severe winters, returning from the ground to bloom the following autumn. It’s usually sold in the form of ‘Gibralter’, whose 6-foot stems splay under the weight of its prolific flowers. Other cultivars with pink or white flowers are sometimes available. For tidier winter looks, these shrubs can be pruned back in fall and mulched with Fafard Natural & Organic Compost to keep them protected through winter.

Last in flowering time but certainly not in garden value is a species from forests of central and eastern North America. In the wild, witch-hazel (Hamamelis virginianaLespedeza thunbergii 'Gibraltar') forms a large, often straggly understory shrub whose sparse, spidery yellow flowers are hidden among its yellowing leaves from early to mid-autumn. In the garden, however, it’s an entirely different animal – especially in the form of the recently introduced ‘Harvest Moon’. Bearing a showy profusion of relatively large flowers on naked branches, this cultivar’s floral display rivals that of winter-blooming witch-hazels such as ‘Arnold Promise’. Give it a good, humus-rich soil in sun to partial shade and it will develop into a dense 12-foot shrub that acquits itself well even when not dazzling onlookers with its fragrant, sunny blooms. Where space is limited, try ‘Little Suzie’, a compact, 5-foot witch-hazel selection that works well in foundation plantings, hedges, and other tighter niches.