Grow your plant collection faster

Expanding your collection of plants with seeds is interesting and inexpensive, but vegetative propagation methods, such as division and rooting cuttings, will help you quickly increase the supply of plants you already have.

Many plants are surprisingly simple to propagate, although some are challenging or impossible to coax into producing new roots.

Learning a few basic propagation skills can help you turn a specimen into a lush bed, or provide a way to share your riches with fellow gardeners.

When pleased with their site, many popular perennial flowers grow into thick clumps that can easily be dug, divided and replanted. Or you can simply lift stems that appear along the outer edge of a clump in spring and dig them up without disturbing the parent plant.

Some of the easiest perennials to propagate by division include:

• Ajuga
• Bee balm
• Daylily
• Heuchera
• Japanese anemone
• Liriope
• Aster
• Chrysanthemum
• Dianthus
• Hosta
• Lamb's ear
• Phlox

As plants develop new stems, they prepare for possible disaster by stowing away special cells in their nodes — the places where leaves join the stem.

• If you pinch off the stem's tip, the nodes will morph into new stems or leaves. But if you leave the tip intact, nodes buried in moist soil — or sometimes in plain water — will mobilize and grow new roots.
• It's not magic; there are some essential things to know to make your stem rooting projects successful.

To root, stem cuttings demand high humidity paired with limited indirect light.

• Give cuttings only enough light to keep them alive, and cover them with a plastic tent so the leaves don't have to replenish lost moisture.
• Until the cuttings grow roots, they have no way to gather enough water to keep unprotected leaves provided with the water they need.
• Try to keep humidity close to 100 per cent.