Black spots on a pluot could be either from the sun (sunburn on the fruit) or, more likely, a nutritional problem.
Bob Morris is a horticulture expert and professor emeritus of the University of Nevada, Las Vegas. Visit his blog at xtremehorticulture.blogspot.com.
Bunch diseases attack only grape bunches. At the beginning of summer is when we notice disease problems on the berries of grapes such as the so-called bunch rots.
A first-time soil test establishes a baseline and tells new homeowners at the beginning what’s adequate about their soil chemistry and what’s missing.
We are nearing the end of any soil applications of iron fertilizers that work. Once early spring through early summer has passed, the only thing that cures leaf yellowing is the leaf sprays applied directly to yellowing leaves.
Canary Island palm trees have a big head that produces heavy shade so it’s possible that the lower fronds may die due to a lack of light. If the lower fronds are dying, the palm tree needs to be pruned.
As we water plants infrequently, the roots extract water and grow into deeper layers of soil. Deep rooting of plants is the main reason good gardeners say, “Water plants deeply but infrequently.”
To prevent fruit production in an ornamental tree, spray the it with a chemical every year to get the fruit to drop when it’s still small. Spray the entire canopy of the tree when as many of the flowers are open as possible.