With rounded or heart-shaped, silver-gray leaves, the silver dollar plant (Eucalyptus cinerea) makes a striking visual statement in your garden, whether you grow it as an annual 6-foot bushy shrub from seed or as a 60-foot-tall tree. It's native to southeast Australia and thrives in U.S. Department of Agriculture plant hardiness zones 8 through 11. The plant does best when planted in well-draining soil and in full sun where it can get at least six hours of direct sunlight each day.
Water requirements for established silver dollar plants vary. Like any plant, it needs regular weekly watering for the first year until it is established. After that, the plant is drought-tolerant, and you can water it every few weeks if you have it planted in your yard or even skip watering althogether. Continue with weekly watering if your silver dollar grows in a container on your deck or patio, especially in very dry and hot climates.
For a silver dollar tree, prune crossing branches, dead branches and those that interfere with walking. To keep a eucalyptus silver dollar as a bushy shrub, prune it in its second year by cutting off the main stem about 3 inches from the ground to encourage multiple stems to grow. For the next year, allow the largest three or four branches to grow, cutting off more spindly stems. Thereafter, let side shoots develop from the three or four branches and again remove new spindly stems from the base
Lowest Temperature:20° to 30°F (-7° to -1°C) Freezing temperatures over an extended period of days can damage or kill a eucalyptus silver dollar plant. If you plan to keep the plant outdoors, cover it with a blanket draped over a frame for protection. For a plant grown in a container, cut the plant back to the ground and keep it in a cool, dark garage or basement over the winter.