Andromeda (Pieris japonica) is sometimes called lily-of-the-valley bush for the chains of tiny bell-shaped white or pink flowers that hang from the tips of its branches from late winter through early spring. The broad-leafed evergreen's ability to add color and texture to the garden in late winter when not much else is happening is a winning trait that brings gardeners back for more of the shrub. Suitable for U.S. Department of Agriculture plant hardiness zones 4 through 8, andromeda propagates readily from tip cuttings taken in midsummer.
Water your andromeda the night before you plan to take your tip cuttings so your plant is fully hydrated.
Spray the blades of bypass pruners with household antiseptic cleaner to decrease the potential of transferring a disease from a plant you previously pruned to your andromeda or your new cuttings. Wipe the pruners dry with a paper towel.
Cut 6 to 10 inches off the tips of main branches that are less than 1 year old. Terminal shoots root better than the tips of lateral branches. The longer the cutting, the sooner you will have a plant that makes an impression in the garden. Cut the shoot at a 45-degree angle, just below a leaf node.
Strip the leaves from the bottom 2 inches of each cutting. Cut the remaining leaves in half with scissors cleaned the same way as your pruners. The leaves produce hormones and carbohydrates that speed rooting and growth, but reducing their surface cuts the amount of moisture the plant loses through evaporation through the leaves, or transpiration.
Fill clean 4-inch pots with a good-quality potting mix or combine equal parts peat moss and perlite. Thoroughly moisten the soiless mix. Poke a hole 2 inches deep in each pot with your fingertip or a pencil.
Dip the end of the cuttings in rooting hormone powder, and insert them in the holes without knocking off the rooting hormone. Press the potting mix around the cuttings with your fingers so they stand upright.
Place the pots on a nursery heat mat set to 70 to 75 degrees Fahrenheit in a room that is 60 to 65 F and has bright, indirect light. Cuttings can be slow to root without bottom heat.
Cover the plants with plastic, propped away from the cuttings with 10-inch dowels. Keep the plants watered, misting occasionally with a spray bottle until they show signs of new growth, in about six weeks.