Subshrubs have the unique characteristics of both herbaceous and woody plants. Their bases are woody but they produce new herbaceous growth during the primary growing season. Many herbs fall into the subshrub category, such as:
Sunset
Hyssop (Agastache rupestris)
Form: Vase shaped plant maturing to 2 feet high by 1.5 feet wide
Exposure: Full sun
Color: Flowers vibrant pink, purple and orange
Bloom Time: Long bloom season summer to fall
Attributes: Fragrant, Attracts Bees & Butterflies, Ornamental, Medicinal, Culinary
USDA Hardiness Zones: 4b-9
Englis
h Lavender (Lavandula angustifolia)
Form: Upright clumping growth habit, 1.5 feet tall by 2 feet wide
Exposure: Plant in full sun to partial sun in evenly moist and rich soil
Color: Green-gray to green–purple foliage in the summer, silver-green to gray-bronzed in the winter. Flowers blue-purple, lavender, violet-blue, or white-pink, depending upon cultivar Bloom Time: varies with cultivar
Attributes: Semi- evergreen, Fragrant, Ornamental, Medicinal, Culinary
USDA Hardiness Zones: 5-9
Garden Sage (Salvia officinalis)
Form: Woody Stems, 3′ tall and wide,
short lived, needs replacing every 3- 4 years
Exposure: Full Sun
Color: Grayish foliage – Flowers blue to purplish Bloom Time: May- July
Attributes: Water Conserving Evergreen, Fragrant, Ornamental, Medicinal, Culinary
USDA Hardiness Zones: 5-9
Russian Sage (Perovskia atriplicifolia)
Form: Woody base with upright stems 3 to 4.5 feet tall
Exposure: Full sun, hardy, drought tolerant
Color: Grayish-white stems, silver-gray foliage with small tubular deep blue or lavender flowers
Bloom Time: July – September
Attributes: Pungent fragrance, attracts butterflies, Ornamental, Culinary, Medicinal, deer-resistant
USDA Hardiness Zones: 3-9
Deerwood (Lotus scoparius) (California Broom)
Form: Woody base with arching airy branches, grows to 3 feet
Exposure: Full sun to partial shade
Color: Flowers begin as yellow, turning to orange
Bloom Time: April-June
Attributes: California native, feeds numerous wildlife: hummingbirds, bees, butterflies and deer. Bees relish this plant! Nitrogen fixing capabilities
USDA Hardiness Zones: 6-10
Wormwood (Artemisia absinthium)
Form: Tall straight clusters of silvery-green branches, foliage spirally arranged, grows 3 feet tall by 2 feet wide.
Exposure: Full sun to partial shade, drought tolerant
Color: Greenish-grey foliage clad with silky-silvery “hairs”, small yellow tubular flowers
Bloom Time: June-October
Attributes: Companion plant to suppress weeds – roots secretes substances which inhibit the growth of surrounding plants. Ornamental, Culinary, Medicinal
USDA Hardiness Zones: 4-9
Pruning Subshrubs
Subshrubs are not pruned like softer herbaceous herbs, such as germander, marjoram, oregano, and winter savory, or even other woody plants. Subshrubs are never pruned during the cool fluctuating temperatures of fall and winter and you never cut them to the ground. Subshrubs should be pruned in early spring once signs of new growth appear and then only to remove dead and broken wood. In some cases, pruning can wait until after the first bloom, but technically you should avoid pruning subshrubs because doing so could be harmful to the plant.
by Carlotta Lucas