Tree roses are not trees but roses that have been grafted onto a trunk that has been grafted onto a rose rootstock. While they look exotic, tree roses have the same growing requirements as regular roses and are bothered by the same pests and diseases. Tree roses come in two shapes, a compact lollipop or a weeping form. The grafts of both forms need to be protected from swaying in strong winds and winter damage because of freezing temperatures. Tree roses create an interesting look in an otherwise blah area of your garden, and with care, can thrive for years.
Growing a tree rose
Select a tree rose cultivar hardy in your zone. If you don't live in a hardiness area, tree roses may be grown in containers and overwintered indoors. Tree roses should be planted in spring after the danger of frost has passed.
Choose a spot of well-drained soil with a pH of 6.0 to 7.0. The site should receive at least six hours of full sun a day. Eastern exposure is best as the morning sun evaporates dew from the leaves, but a southern or western exposure also will work. Avoid northern exposures.
Dig a hole twice as wide and deep as your tree rose's root ball. Mix the soil removed from the hole with compost until you have a 50/50 mix of soil and compost. Refill the hole with the compost-soil mix until it is just large enough to accommodate the root ball and places the graft between the rootstock and the trunk stock 2 to 3 inches above the soil.
Place the tree rose in the hole and backfill with soil. Make sure the tree rose remains straight as you fill the hole.
Insert a stake into the soil just outside the root ball. Attach the tree rose to the stake with at least two elasticized tree ties. Place the ties 2 to 4 inches above the graft between the root stock and the trunk stock and 1 to 2 inches below the graft between the trunk stock and the rose.
Apply mulch 1 to 3 inches deep around your tree rose. Pull it back from the trunk to prevent damage. Make sure the mulch does not cover the graft between the root stock and the trunk stock.
If you are growing your tree rose in a container, place rocks or pieces of broken clay pots in the bottom of the container. Fill the container, sized for your mature tree rose, with a general-use potting soil. Plant and stake the tree rose as you would in the garden.
Deadhead your tree rose when blooms fade. In the spring, just after bud break, prune off dead and broken branches. Prune back foliage that has powdery mildew or black spot.
Give your tree rose a deep watering three to four times a week. Water the soil around the tree rose. Do not get the foliage wet as this will promote powdery mildew and black spot.
Fertilize your tree rose three times a year -- in early spring when flower buds are swelling, again just after your tree rose begins to flower and then in late summer after most of the blooms have faded. Use a liquid rose food; follow package directions for rate of application.
When your tree rose loses its leaves in the fall, wrap the entire plant with burlap, leave the top open and secure with twine. Or you can just dig up your tree rose and store it in dampened peat moss in a warm garage or basement. If your tree rose is planted in a container, bring the container inside for the winter.