Plants

Halesia carolina 'Arnold Pink'

[Pink Carolina Silverbell]

This small tree is interesting when in bloom with pink bell-shaped flowers that are larger than the straight species, but this plant is rather neutral otherwise. However, it is relatively trouble free and useful in many situations as a neutral background plant, or for its flowers. Best grown as a single stem and allowed to branch low (20-30"). Does not transplant well (a particular problem with field-grown plants).

Hamamelis vernalis

[Vernal Witchhazel]

Earliest blooming shrub for the Midwest. Good as a neutral filler for the border with quiet seasonal interest. More pH tolerant than Hamamelis virginiana. Should not be pruned (tip pinching would be acceptable to direct growth). Not as showy in bloom as Hamamelis mollis, the Chinese Witchhazel, or its hybrids.

Hedera helix

[English Ivy]

Tolerant of heavy shade to full sun except at the northern limits of its useful range, where some protection from full winter sun is necessary. Useful as a groundcover only, not as a vine, in Zone 5b, except hardiest cultivars in sheltered sites. Vigorous and can be a weed problem in certain regions of the country (like the NW US) where it can smother woodlands. Poisonous fruits, but it generally takes many years for it…

Hedera helix 'Thorndale'

[Thorndale English Ivy]

'Thorndale' is a very hardy cultivar that has large, glossy leaves with striking white veination. Tolerant of heavy shade to full sun except at the northern limits of its useful range, where some protection from full winter sun is necessary. Useful as a groundcover and vine. Vigorous and can be a weed problem in certain regions of the country (like the NW US) where it can smother woodlands. Poisonous fruits, but it generally takes many…

Heuchera americana 'Palace Purple'

[Palace Purple Coral Bells]

Coral bells does best when grown in organically rich soils that are well drained and in full sun. To encourage continuos bloom, remove the old flower stems. Every 3-4 years in the spring, the clump should be divided.

Hydrangea anomala ssp. petiolaris

[Climbing Hydrangea]

Among the best ornamental vines. Holds to a wall using root-like holdfasts arising from nodes. Grows best in shaded areas. Slow to establish. Best to transplant from a container. Although it can eventaully reach up to 80 feet, its size is controllable, if desired.

Hydrangea macrophylla 'Bailmer' [sold as Endless Summer®]

[Endless Summer Bigleaf Hydrangea]

'Bailmer' is an excellent mophead (hortensia) cultivar for cold climates, as it is hardy to USDA zone 4 and produces flowers on both old and new growth, unlike other Hydrangea macrophylla variants. As the name Endless Summer suggests, this plant blooms all summer, and even into the fall. An acidic soil will produce a very blue colored flower and alkaline pink. High quality foliage. Performs poorly on hot dry sites. A few pest problems, including…

Hydrangea paniculata 'Bombshell '

[Bombshell Panicle Hydragea]

Hypericum kalmianum 'Ames'

[Ames Kalm St. John's Wort]

Hypericum kalmianum 'Ames' is a compact, mounded deciduous shrub that produces attractive, interesting, bright yellow flowers in mid to late summer. 'Ames' is reported to have better winter hardiness than the straight species.

Hypericum kalmianum 'Gemo'

[Gemo Kalm St. John's Wort]

Hypericum kalmianum 'Gemo' is a compact, mounded deciduous shrub that produces a profusion of small, interesting, bright yellow flowers beginning late spring and continuing all the way into fall.