Despite their manicured geometric designs and clean lines, eugenia (Eugenia spp.) topiaries are relatively easy to care for. Eugenias are resilient shrubs, hardy in U.S. Department of Agriculture plant hardiness zones 9 through 11. They tolerate poor soil with light acidity to high alkalinity, which corresponds with a pH ranging from 5.0 to 8.5. If you're new to topiary care, consider a slow-growing "Monterey Bay" (Eugenia myrtifolia "Monterey Bay") or "Teenie Genie" (Eugenia myrtifolia "Nanum"), which come trained in 2- to 15-gallon containers.
Set the eugenia in an area that receives partial to full sunlight and allows 6 to 12 inches of space around each globe. This space gives you room to trim and the foliage room to breathe and get sunlight. Space consecutive eugenias 36 to 60 inches apart.
Use a container that has drainage holes in the bottom. Water eugenias when the top 1/2 to 1 inch of soil dries out. During winter, water the eugenia three to four times a week. If you just started growing a potted eugenia, you can immerse its container in water, for example, in the bathtub, for a couple of minutes to saturate the growing medium; then let the excess water drain from it. Start your watering regimen when the top 1/2 to 1 inch of soil dries out.
Fertilize eugenias once each season using 3/4 cup of 5-5-5 wettable organic fertilizer mixed with 1 gallon of water per tree during the first year. Apply the fertilizer with a watering can. Young roots are susceptible to nitrogen root burn, and starting with an organic fertilizer helps ease eugenias into a chemical feeding regimen. After the first year, fertilize eugenias once every season using 1 tablespoon of 10-10-10 NPK fertilizer mixed with 1 gallon of water. Don't apply fertilizer to the trunk or foliage.
Trim eugenias every two weeks after they leaf out, using clean manual hand trimmers or garden shears; if needed, adjust the trimming frequency according to vigor. Pinch off shoots as they appear, to maintain the desired shape of the foliage globes. Wipe the trimmer blades with alcohol between cuts.
Trim eugenias every two to three weeks using manual hand trimmers or garden shears. Pinch off shoots as they appear, to maintain the desired shape of the foliage globes. Wipe the trimmer blades with alcohol between cuts.
Check eugenias' foliage for aphids during periods of new growth. You'll usually find honeydew, a sticky fluid released by aphids, on the leaves if the bugs are around. If you notice the leaves overrun with aphids, which are the size of a pencil eraser at their largest, spray them off with water; eugenias don't have any major pests and disease problems, so you they won't chemical pesticides and fungicides.