Garden Guide: Habranthus-Hypericum
Habranthus - Hypericum
PLANTING: Plant in full sun and fertile, well drained soil that is on the neutral side. MAINTENANCE: Excess winter moisture can be lethal, so ensure good drainage. Foliage appears after the blooms. Zones 7-11.
HAMAMELIS species and cultivars - Witch Hazel
PLANTING: Space plants according to ultimate size. Choose a moist, well drained, organic soil that has been prepared with compost or leaf mold. Plant Hamamelis in full sun or partial shade, the latter being preferable farther south. We recommend protection from cold winters. MAINTENANCE: Water well, especially during spring and early summer. We recommend a summer mulch to help conserve moisture. Some species or cultivars may be trained to a single leader for maximum height , or espailered against a wall. Zones various.
HELICTOTRICHON - See Grasses, Ornamental
HELLEBORUS species and cultivars
PLANTING: Set plants 12 to 18 inches apart, in a rather fertile soil that is well-drained but moisture-retentive. Helleborus does best in partial shade, but can tolerate full sun in northern areas. For the taller species and cultivars, choose a somewhat sheltered location. MAINTENANCE: We recommend a year-round mulch, to conserve moisture and keep the soil cool. If plants must be divided, do so carefully, as they tend to be brittle. H. orientalis hybrids transplant readily; others are happier left undisturbed. If slugs appear, use appropriate bait. Zones 3-8.
HEMEROCALLIS cultivars - Daylily
PLANTING: Set plants 12 to 18 inches apart. Choose a sunny or lightly shaded location (many varieties, including the pastels, prefer partial shade as they tend to fade in direct sun), and in soil that is well-drained and moisture-retentive - but not likely to become waterlogged.MAINTENANCE: Water well during periods of drought; we also recommend a summer mulch to conserve moisture. Annual applications of a fertilizer high in phosphates are also recommended. If slugs pose a problem, apply slug bait around the crowns just before or as shoots begin to emerge. Cut flower stems after blooming. Divide reblooming types every 2 years. Zones 4-9.
HEUCHERA species - Coral Bells or Alum root
PLANTING: Space plants 12 inches apart. Choose a sunny or lightly shaded, sheltered location where the soil is rich and well-drained. MAINTENANCE: Water during periods of drought. Apply a protective winter mulch once the ground has frozen. Plants may, if necessary, be divided every 3 to 4 years. Zones 3-9.
PLANTING: Plant in well-drained but moisture-retentive soil of high organic content, spacing 18 inches apart. While it will tolerate sun, in the North, it is best in partial shade. MAINTENANCE: Remove spent flower spikes to prolong bloom. A 2 to 3-inch mulch is beneficial. Water during periods of drought. Divide, as needed, in spring, (fall in the South.) Zones 3-8.
PLANTING: Set plants out in a loose, moisture retentive soil enriched with generous amounts of well-decomposed organic matter. Full sun to light shade is required. Space plants 18 to 36 inches part. MAINTENANCE: A mulch is recommended to preserve summer moisture; do not allow plants to dry out during the growing season. Cut back hardened brown stalks to the ground in the fall, or in early spring, before new growth begins. Toward the northern limit of their range, a winter mulch of pine straw of salt hay is recommended. H. moscheutos is slow to break dormancy in the spring - so be careful not to remove it accidentally. More drought tolerant than other species and varieties. Zones 5-10.
PLANTING: Space plants 6 to 10 feet apart in a sunny location, with well drained soil. MAINTENANCE: Since they flower on new growth each year, plants can be pruned each spring to any desired height. For grafted standard form, remove any shoots that sprout along the trunk during the growing season. Prune the stems that form the standard in early spring before new growth begins to the desired size and shape. Zones 5-9.
HOLLYHOCK - See Alcea
HOSTA - Shade Lily, Plantain Lily
PLANTING: Set plants 15 to 30 inches apart, depending on the ultimate size of the cultivar or species. (Set very dwarf kinds 9 to 12 inches apart.) Hostas are among the best of plants for shaded situations, but some also succeed in full sun, as they become larger and more mature. The hotter the summers, the more shade will be necessary to prevent scorching the foliage.A high shade canopy providing dappled light is ideal. Those with blue foliage are outstanding in the shade, while the yellow/gold types will effectively light up dark areas, but prosper, too, in considerable sun. Individual cultivars of green-gold or variegated patterns vary appreciably in the amount of sun they can tolerate. While widely tolerant of soils, hostas do best in a well-drained soil that still affords ample moisture - the sunnier the location, the moister the soil should be. Incorporate generous amounts of humus in the soil, particularly those on the limy or alkaline side. MAINTENANCE: A winter mulch is extremely important the first winter, to prevent heaving of unestablished plants as a result of alternating freezes and thaws. Once established, hostas can be left undisturbed for many years, but as landscaping needs dictate, can be moved at almost any time during the year, except midsummer. Zones 3-9.
PLANTING: Set out plants 18 inches apart, ideally in a moisture-retentive soil and in a cool, light shaded situation. The striking red colors of the foliage are best developed when more light is available. Houttuynia also makes an attractive pot plant or hanging basket plant. MAINTENANCE: Keep in a contained area as plant will spread by creeping stems. Ultimate size will range from 6 to 24 inches, depending on soil richness and available moisture. Zones 3-8.
HYDRANGEA species and cultivars
PLANTING: Space according to ultimate size. Choose a good garden soil, high in organic matter that will help keep ample moisture available to the roots. The location should be sunny or partly shaded, the latter being preferable in dry areas. If the pH of your soil is too high (alkaline), it can be reduced (made more acidic) by the addition of one tablespoon or more of Aluminum Sulfate per plant - this will make your flowers a deeper blue. MAINTENANCE: An annual mulch of compost is beneficial. In very cold or exposed locations, “hill” up the soil and mulch the base of the plant with pine needles or leaves. Most species require little pruning except the removal of dead flower heads after blooming or in early spring. For H. arborescens, prune the previous year’s flowering wood to the ground in early spring. For H. macrophylla (H. hortensis) and H. serrata, thin out two- or three-year-old flowering shoots at ground level to promote vigorous new growth. H.petiolaris should be pruned only for aesthetics. Zones various.
HYPERICUM species - St John’s Wort
PLANTING: Plant H. calycinum 18 inches apart in a light loam soil, preferably in full sun, though it is tolerant of hot, dry soils and light shade. Soil should be enriched with organic matter. Space 12 to 15 inches apart in average, well drained garden soil. MAINTENANCE: South of zone 5, cut old weak shoots back to the ground in the spring and prune remaining shoots back to 10-12 inches. Zone 5 and north, prune back to ground level in early spring. Does not perform optimally where temperatures drop below -5°F. Mulch with leaf mold every other year. Zones various.