Q: Last spring I planted a clematis right next to my wooden trellis. The vine just sat and sulked, putting out only a few spindly shoots. How can I get it to climb and produce the masses of blooms I’ve seen elsewhere? — Don Shields, Evanston, Ill.
A: Most clematis species take a year or two to acclimate themselves to a new site, often appearing not to grow when in fact, beneath the soil, they’re busy building a strong root system. Have patience — once the roots are well-established, profuse growth will follow. Apply a general-purpose balanced liquid or granular fertilizer in spring and early summer, and be sure to mulch the base of the plant: True to the garden adage “Sunny head, shady feet,” clematis likes to have its foliage amply lit and its roots cool. The best mulches are leaf mold, well-rotted compost, chipped bark, or small rocks (an inch or less in diameter). Because clematis climbs by twining stems and leaf petioles around narrow supports, it has no trouble clambering up wrought iron, bamboo, and metal mesh all by itself, but it needs help scaling broader wooden structures. Secure wires or taut strings to the trellis, both vertically and horizontally, and coax the flexible clematis shoots onto them with your fingertips. Watch closely: Sometimes you can actually see a stem curl around a wire right before your eyes.