Keep magnolia trees blooming with thoughtful care
Q: My magnolia trees were purchased locally and planted about eight years ago. All I get are a few flowers. How do I encourage more blooms?
A: Magnolias can be cantankerous trees. Some, like variety Little Gem, flower soon after planting, where others take years. Growing sites and yearly care do seem to have an influence on when the trees begin to flower. Most need seven or more years to come into full bloom. Help your trees reach maturity and bloom better by keeping the root zones moist but not overly wet. Fertilize once or twice a year for the first three years. Thereafter keep fertilizer applications to only what is applied to nearby lawns and ornamental plantings. Overfertilization and excessive moisture encourages growth without the blooms.
Q: We need a shrub to screen our pool that grows to about eight feet high in an area about eight feet wide. This area only receives four hours of sun. What do you suggest?
A: Reduced sun limits the shrub selection for this site. Perhaps one of the native anise plants would be best with dark-green leaves that can grow a dense hedge. Select either the star anise with yellow flowers or the Florida anise with red blooms. Both can grow well over eight feet tall and up to eight feet wide. They are shade-tolerant, hardy shrubs and grow well in most soils.
Q: I have a Hass avocado started from seed that has grown to 20 feet tall in eight years. I thought I would be eating avocados by now. Does it need another tree nearby?
A: Even though you planted a Hass offspring there may be some hidden parentage in this seedling that prevents early fruiting. Your tree is certainly large enough to bear a crop but maybe still not old enough. Some horticulturists say ten to fifteen years is not an abnormal time to wait for a seedling tree to come into production.
If your tree is flowering, it should produce some fruit by self-pollination. Both male and female flower portions are on avocado trees. But, there are different flowering groups of avocados, and having more trees of a different variety nearby or in the neighborhood could help set the fruits. Keep up normal care of three to four fertilizer applications a year and maintain moist soil during dry times to help produce your crop.
Q: Stromanthe growing in two areas of my landscape gets mostly shade but some sun. About half the leaves have turned a tan color. What should I do?
A: More shade is likely needed by the stromanthe to keep their normally green, red and yellow leaf color. They do not like the sun and as summer approaches, the light levels become more intense and foliage is likely to burn. Also, as the sun moves overhead for summer, the light levels change and more of the foliage may be affected. If adding shade is not possible the plants should be moved to a lower light location.
Q: Sections of my mature ligustrum trees are dying. What could be the problem?
A: Older ligustrum trees become susceptible to what pathologists call cankers. These are usually fungal infections that have entered through wounds caused by pests, pruning or flexing of ligustrum limbs. Usually, the disease organisms are weaker types but able to affect older shrubs. The only cure is to immediately prune out the dead and declining portions back into healthy wood. It would be best to cut these limbs six or more inches past where the affected portions of the limbs or trunks are noted. After pruning, apply a copper fungicide or similar product following label instructions. Also, make sure the ligustrum trees remain moist and fertilize with a slow-release landscape product two to three times a year.
Q: My poinsettias are making good growth. Is it too late to do the trimming?
A: Actually you are right on time for a second pruning of the year. Most poinsettias are given a heavy pruning in March and additional trimmings after each foot to eighteen inches of new growth. Remove about four to six inches of new growth and then allow the poinsettias to produce more shoots. Continue the pruning after each flush of growth until the end of August when the plants are left to mature and initiate flower formation in October that ultimately produces the colorful bracts for December.
Q: Several kalanchoe have been added to the front of my house and were in bloom when planted but now the flowers are gone and I don’t see any buds. Will they continue to bloom for summer?
A: While there are a number of different kalanchoe, the ones normally found at local garden centers with the red, pink, yellow or white flower clusters are short-day plants. This means they only flower when the days are short in length which is late fall through early spring. The plants stop flowering mid-spring through much of fall but continue to make vegetative growth. Colorful kalanchoe presently at stores have been forced to flower and normally do not produce more blooms until fall.
Kalanchoe can be cut back as the flowers decline and then allowed to develop their medium to dark green foliage. Most gardeners treat them as annuals and replace them with seasonal flowers or foliage. Colorful coleus, pentas, bush daisies, Porterweed, or perennial salvia would be good selections for summer.