By Jean Valleau, Valleybrook Gardens/Heritage Perennials

Over the years, various trends in foliage colour seem to come and go. Lately, there has been a resurgence in variegated plants of all kinds, and burgundy or red leaves are ever popular. Silver or gray foliage seems also to hold its own, but the group that I find to be still underused are the gold or yellow-leaved perennials.

     This should be no surprise, I suppose. Given a choice of flower colours, yellow is usually the least popular with garden consumers in general, so why should foliage be any different? In addition, sometimes gold-leaved plants have a tendency to look unhealthy, at first glance… somehow as though a good dose of high-nitrogen fertilizer is called for! So, these gilded cousins to more familiar green leaved plants do not always sell themselves - they need a little extra help.

     Perennial gardeners go through various stages, beginning as avid fans of anything that flowers. It can take years to progress through to a full appreciation of foliage texture, colour and contrast, but eventually many gardeners achieve a realization that foliage interest is critical in the perennial garden, if we are to maintain an interesting effect throughout the season. Golden and yellow foliage is yet one more piece of ammunition the clever designer has against border boredom.

Origanum vulgare 'Aureum'
Golden Oregano
Height: 15-30 cm; Spread: 45-60 cm, USDA Zones: 4-9
One of my absolute favourite groundcovers for hot, sunny sites, Golden Oregano makes a low mound of bright chartreuse-yellow foliage first thing in the spring, a wonderful contrast to spring-blooming bulbs, especially in combination with Grape Hyacinths. Near the middle to end of June, shear the whole plant back to about 2 cm, just as the stems begin to grow upright and buds appear. This forces new growth that will remain bright golden and low to the ground for the rest of the season.

Dicentra spectabilis 'Goldheart' (PBR applied for)
Goldheart Bleedingheart
Height: 60-75 cm; Spread: 60-75 cm, USDA Zones: 2-9
This terrific new spring-bloomer first appeared in England about five years ago, and has quickly been tissue cultured and distributed all over the world. The habit is exactly like the Old-fashioned Pink Bleedingheart, with lush bright yellow foliage making an appearance in mid spring, followed by a late spring display of large bright pink locket flowers. After blooming is over, give plants a quick shearing back to 15 cm to encourage fresh foliage and a low habit for the rest of the season.

Humulus lupulus 'Aureus'
Golden Hops
Height: 180-700 cm; Spread: 60-75 cm, USDA Zones: 2-9
The Golden Hops vine has been widely grown in European gardens, yet was seldom available here in Canada until recently. This is a herbaceous vine, dying back right to ground level each winter, but quickly making a fresh start in the spring, reaching full size by mid summer. Foliage is coarse and rough in texture, bright golden-green in colour, making for a showy contrast to other vines such as dark purple Clematis, or all by itself scrambling up a post or pergola. I find that it resents summer drought, so choose a rich, moist soil somewhere that won't dry out. Clusters of cone-like flowers and seedheads sometimes appear in late summer and fall.

Saxifraga 'Cloth of Gold'
Golden Mossy Saxifrage
Height: 10-15 cm; Spread: 20-30 cm, USDA Zones: 4-9
Shaded rock gardens can present a challenge to the designer, since the majority of the alpine and rock garden plants available have a distinct liking for well-drained, full sun locations. The mossy Saxifrage are an exception, preferring the even moisture and cooler exposure of partial shade, especially protection from the hot afternoon sun. This selection forms a dense, evergreen cushion of tiny bright yellow leaves, bearing short stems of white cup-shaped flowers in late spring. These are not at their best in the muggy summers of southern Ontario, but gardeners in northern regions will succeed easily with all kinds of Saxifrage.

Hosta 'August Moon'
August Moon Hosta
Height: 50-60 cm; Spread: 75-90 cm, USDA Zones: 2-9
This is one of the older gold-leaved Hosta, but still an excellent garden performer. Foliage of 'August Moon' is rounded in shape, the large leaves deeply crinkled or quilted. Clusters of near-white flowers appear in mid summer, held just above the foliage mound. Like any medium to large Hosta, this will take a couple of years to really settle in and reach a mature specimen size. The effect in a dark, shady area is to add a false sense of light, as if an overhead pin spot was focused directly on the plant. I feel that as a group, the gold-leaved Hosta are terribly underutilized, and are an excellent "special effect" plant.

Lonicera japonica 'Aureoreticulata'
Yellow-net Honeysuckle
Height: 120-210 cm; Spread: 60-75 cm, USDA Zones: 5-9
Why this vine has never been more widely grown in the past is a mystery to me. Unlike most climbing honeysuckle, this is grown for the foliage rather than the flowers. Leaves are oval in shape, about 3 to 4 cm in length, bright green with contrasting yellow veins that give a bold, netted effect. The new spring growth is especially colourful. Clusters of creamy, fragrant flowers appear reliably in mild winter regions, but in Zones 5 and 6, this is more of a foliage specimen. Prune plants back to about 30 cm every couple of years to encourage new stems to develop, since these give the best foliage effect. Plants will need a trellis to climb, or else just let them cascade over a wall or at the front of the border. Full sun to partial shade is ideal.