Growing tree roses in containers adds a new element to your gardening, as containers enable gardeners to place tree roses along walkways, on a patio or balcony, or anywhere a spot of color is needed. Caring for tree roses grown in containers isn't difficult, but regular care is crucial to keep containerized plants nourished and hydrated. A tree rose is any type of rose, such as a tea rose, floribunda or grandiflora or even climbers, grafted onto a sturdy upright trunk.
Plant your tree rose in a sturdy container filled with a good quality commercial potting mixture. The container must have a drainage hole in the bottom, and should be at least 15 inches deep to allow growing space for the roots. Width of the container should be at least 18 inches. Plant the tree rose at the same soil depth that it was planted in the nursery container.
Place the tree rose where the plant will receive at least six hours of sunlight per day. If you live in a warm climate, move the rose into the shade on hot afternoons. Rotate the rose once or twice a week so growth will be even.
Water the tree rose whenever the top inch of potting mixture feels slightly dry. Place the container where bottom drainage won't be impeded, then water slowly until water runs through the drainage hole. Spread a 1- to 2-inch layer of finely chopped bark mulch over the top of the soil to keep the roots cool and damp.
Fertilize the tree rose every week, using a general purpose water-soluble fertilizer. Use the fertilizer according to the guidelines on the label, but dilute the solution to a quarter strength.
Move the tree rose into an unheated room during the winter. The room must be cool, but the tree rose should never be allowed to freeze. Water just enough to keep the potting mixture from becoming bone dry. Cover the potting mixture with a sheet of plastic to keep the atmosphere moist. Move the tree rose back outdoors after the last frost in spring.