When Leaves Come First

By Janet Loughrey, special to HGTV.com
There are few pleasures that gardeners look forward to more than the first flowers of spring. After the bloom fades, however, all that's left is the foliage. Those leaves don't need to be boring; foliage can come in an endless array of colors.
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Euphorbia Tasmanian Tiger' (photo courtesy of Wayside Gardens)
Some of the most fascinating foliage is variegated, meaning it has two or more colors. Leaves can be splashed, splattered, veined, streaked, marbled, striped or mottled. Euphorbia characias 'Tasmanian Tiger' has thin, creamy margins; Agave 'Spot' has irregular splotches. Those with consistent patterning in each leaf are generally more highly prized, but some such as Houttuynia cordata 'Chamaeleon' display an uneven mix of colors.

Plant breeders usually first notice variegation in a "sport," a mutant offshoot of a branch that is different from the original plant. The abnormal distribution of chlorophyll that creates the odd colorization can be a happy accident or the result of a virus, mineral deficiency or environmental stress. Variegation interferes with a plant's ability to photosynthesize because there's less chlorophyll in the leaves, so the resulting varieties are generally less vigorous and produce fewer blooms. Some, particularly those with white or yellow foliage, can burn if exposed to full sun or cold winds. The intensity of foliage color can vary according to the amount of sun or shade. Those with purple, yellow or brown leaves have the best coloring in full sun. White or creamy hues perform best in shade.

Not all sports are garden-worthy. Some have a tendency to "revert," or return back to their more vigorous parent. With those that exhibit occasional reversion, the green leaves or branches can simply be trimmed out to prevent the entire plant from turning back to green.

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Polemonium 'Stairway to Heaven' (photo courtesy of Terra Nova Nurseries)

Breeders do their best to make sure new cultivars will perform well for gardeners. They also look for ways to improve existing varieties. In the mid 1990s, variegated Jacob's ladder (Polemonium caeruleum 'Brise D' Anjou') was introduced with great fanfare. The lacy creme-and-green striped foliage topped with pale blue flowers was an instant hit. However, 'Brise D' Anjou' didn't do as well in regions with hot, humid summers. A recent introduction of variegated Jacob's ladder (Polemonium reptans 'Stairway to Heaven') is more vigorous and heat-tolerant.
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'My Monet' weigela (photo courtesy of Wayside Gardens)
Shrubs are generally versatile and easy to grow, and weigelas are among the most reliable in the garden. A familiar standby is W. florida 'Variegata', with broad yellow leaf margins and pale pink flowers in spring. 'My Monet' offers a striking mix of pink, green and cream foliage and bright pink flowers in spring. This dwarf beauty (12 to 18 inches tall and 24 inches wide) is effective in mass plantings, at the edge of a border or in a container.
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'Light O Day' hydrangea (photo courtesy of Bailey Nurseries)

Recent introductions of mophead hydrangeas such as 'Endless Summer' bloom on new wood, a breakthrough for colder climates where these popular shrubs die back to the ground in winter. Hydrangea macrophylla 'Light O Day' (syn. 'Bailipse') has a crisp white edge on the leaves. This improved variety blooms reliably on new wood and is hardier than other variegated forms. The lacecap flowers come in hues of pink or blue surrounded by bright white petals. 'Light O Day' performs best in dappled shade

Woody and herbaceous perennials come in a wide selection of variegated forms, from reliable long bloomers to stately ornamental grasses and tidy groundcovers.