Ever since my romance with plants began 30 years ago, I have been driven to collect and breed hardy plants with gorgeous leaves. Among my favorites are the foamflowers (Tiarella spp.), natives of woodlands across North America and in Asia. But exceptional foliage isn't their only strong point. It's the contrast of frothy flowers against bold, maple-like leaves that makes them so worthy of attention. The native movement is in full swing, and planting these undemanding plants fulfill everyone's sustainability goals!

In recent years, hybridizers have lifted their paintbrushes to concentrate on this little group of lovely plants. Their newest selections and hybrids bloom longer, produce more and showier flowers, and often rebloom. Tough, evergreen below USDA Zone 5, and tolerant of the deepest shade, these superior foamflowers are finding a home next to hostas in many a garden. The hybrids all bloom better and are much more uniform than seed-grown varieties.

CARE AND FEEDING OF FOAMFLOWERS

Foamflowers are quite easy to maintain. Trim off flowers after blooming, and feed and mulch once a year. I have foamflower patches 15 feet wide that I feed with a balanced (14-14-14), timed-release fertilizer from a whirlybird spreader in late winter (early February for me) before growth comes on. With the first warmth of spring, the fertilizer is there for the plants. I recommend using a micro-prill formula such as APEX 14-14-14 that releases nutrients in a very controlled way. For mulch, use leaf mold because it quickly contributes to the soil the humus foamflowers crave.

Some people prune winter-burned leaves off foamflowers, but I prefer to leave them on, as they protect buds from drying winter winds which can top-kill plants. CARE MUST BE TAKEN. Do not bury the crowns of the plants, especially with manure, this will KILL THE PLANTS! Foamflowers are often covered by fallen leaves in autumn and sprout through this layer in spring, but I like to expose their crowns to enjoy the earliest growth in February when I am desperate for green in the garden!

Foamflowers are relatively disease- and pest-free, but some forms are prone to powdery mildew, especially after being drought-stressed. An organic approach to controlling mildew is to spray the foliage with a baking soda/soap solution (see recipe at DIRECTION) or Sulfur. Other mildewicides should be wettable-powder-based (such as Triadimefon, Triforine, Thiophanate-methyl, Propiconazole, or Potassium bicarbonate) since petroleum-based formulae can burn foliage.

Vine weevil and strawberry root weevil are also occasional nemeses. Low-toxicity pyrethrins are effective against the adults with two considerations: timing (spray at dusk since weevils are nocturnal feeders), and timing (make 2-3 applications in late May to mid June). Weevilicide can also be attained by killing the larvae with parasitic nematodes (Nemasys). Don't apply nematodes too early in the year; larvae don't hatch until late summer. I usually drench in September when the soil is moist and warm. Remember to water before and after application. Weevil baits can also be helpful, or hand pick the pests at night and drop them in a bucket of soapy water.

Foamflowers look their best at 2-3 years of age. Divide large specimens very early in spring before the plants have leafed out. Simply push strong pieces of rhizome into fluffy soil to create a new plant. Hybrids will not come true from seed, yielding seedlings that display a hodge-podge of leaf shapes, many inferior to those of the parent plant. Curious gardeners and aspiring plant breeders who want to take their chances anyway should sow fresh seed on top of moist, sterile seed-starting mix. Cover flats with clear plastic and maintain a temperature of 70°F. Ensure that the seed remains moist, and you will see tiny seed leaves in three weeks. When seedlings have a pair of true leaves, prick them out into small pots such as the vegetable packs left over from last year's annuals and grow them on a few months before transplanting them into the garden.

COMBINE FOAMFLOWERS WITH OTHER WOODLANDERS

Foamflowers provide a lovely foil to spring bulbs, lungworts (Pulmonaria spp.) and Hellebores (Helleborus spp.), and Dicentra which enjoy similar growing conditions. They make great companions for ferns like Athyrium and the more shade-tolerant types of coralbell, such as Heuchera 'Paris' and 'Green Spice'. Another good cohort is native wild ginger (Asarum canadense), often seen running with foamflowers on moist, rocky slopes in the wild. In containers, try mixing foamflowers with dwarf forms of impatiens. They are a natural with Hosta, contrasting their delicate texture with the overly bold Hosta foliage. Foamflowers are usually in full leaf and flower before hostas are entirely unfurled and thus "set the stage" for the show to follow.

W. Gary Smith, a landscape architect from Canada designed an amazing planting at Longwood Gardens in Kennett Square, Pennsylvania. In an area called "Pierce's Wood", he planted tens of thousands of Tiarella and contrasted it with Heuchera and Phlox divaricata for a breath-taking experience. His pictures are featured in this article.

Tiarella continue to contribute to the garden with extended bloom in some varieties, rich and interesting leaves all summer, and beautiful bronzing in fall and winter. With all they have to offer, I think you'll agree that every garden with a little shade should have a foamflower!

Resources:

Terra Nova® Website: www.terranovanurseries.com
Charles and Martha Oliver's Book: Heuchera, Tiarella and Heucherella: A Gardener's Guide
http://www.amazon.com/Heuchera-Tiarella-Heucherella-Gardeners-Guide/dp/0713490098