Q. Both this year and last on our Rose of Sharon bush there have been a considerable amount of blooms that never fully open. They turn yellow and drop. -- Harry DeNegre, email
A. In my experience, two things cause Rose of Sharon bud fall: The soil is too dry or too wet. Either condition causes root problems that convince the upper part of the plant to abort its blossoms. On the other hand, some experts say some bud drop is a natural thing, similar to the June fruit drop that occurs on peaches. If water stress isn’t your problem, simply enjoy whatever beauty the plant gives you.
Q. What happened to the hydrangeas this year? I have many hydrangeas in my yard that have bloomed for years and this year some did and some didn't. All these plants look very healthy and are growing like gangbusters. -- Richard von Burg, email
A. I think the deep freeze in mid-January killed lots of bloom stems on plants that were more exposed than others. In my own landscape, hydrangeas that were covered by overarching tree limbs are blooming beautifully now. Those that are more in the open are full of leaves but show no blooms. As long as your shrubs are healthy and we don’t experience severe winter temperatures they should bloom next summer. Don’t forget that ‘Endless Summer’ and other cultivars can bloom even after a winter freeze. Consider replacing some of your shrubs with these reblooming varieties.
Q. We chopped some shrubs recently and the trunk inside was bright yellow. Can you tell me what caused this or if it is normal? -- Judy Berry, email.
A. You probably were working with a barberry or a mahonia. Both have bright yellow sapwood. Pieces of the wood and inner bark can be chopped and simmered with cloth to dye it a rich yellow. The fruit of both is enjoyed by birds, who indiscriminately scatter the seeds in shady places throughout the metro area.
Q. My two-year-old Asian persimmon tree has been dropping developing fruit. Is it poor pollination? How can I stop the drop? -- Tara Levine, DeKalb County
A. Fruit trees vary in their ability to hold fruit while they become established in a growing site. There is a constant "hormonal conversation" between the roots, buds and leaves about what resources are available and what is needed to ripen the fruit. If the root system is not adequate to support many fruit, the plant responds by aborting some of them. This is common in peaches and apples. Unlike American persimmons, Asian persimmons are self-pollinating. As long as your tree is growing healthily, it eventually will reward you with lots of persimmons in the fall.
Q. In my work as a landscape designer, I’m challenged by the different kinds of shade on a site. Shade under a maple tree is completely different from shade on the north side of a house. But both are considered “full shade.” Do you know of a light meter that can be used to figure out how much sun a site gets? -- Karen Faulkner, email
A. This is a question I face all the time! Lawn grass companies claim some varieties will grow in dense shade but no definition of shade is given. I’m positive grass will not grow on the north side of a house where no sun ever strikes the ground. Complicating matters is that the light our eyes can see is not the same light that plants use. Plants need a certain quality and quantity of specific wavelengths of light to photosynthesize effectively. For a good explanation of light in the landscape and sources of light meters, see xrl.us/lightmeasure.
Listen to Walter Reeves Saturday mornings on AM 750 and 95.5 FM News-Talk WSB. Visit his website, www.walterreeves.com, or join his Facebook Fan Page at xrl.us/wrfacebook for more garden tips.
