|What causes holes to form in the leaves of my rhododendron shrubs? And why does it take so long for them to bloom? They are in the shady part of the yard with plenty of fertilizer and mulch is pine needles.|
|Rhododendrons bloom in spring, right around Mother's Day. The flower buds are formed the summer before, so it's important that the plants get adequate moisture while the buds are forming. Some plants bloom every year and others bloom only every other year. It depends upon where they are planted, the kind of rhododendron they are, and the care they receive. Be careful when pruning your plants so you don't accidentally prune off next year's flower buds. It's best to prune them immediately after flowering, and before they begin developing flower buds. Without seeing the leaf damage I can only offer a likely cause - feeding by caterpillars or root weevils when the leaves are still in the bud stage. This type of feeding will result in large holes in the leaves as they unfurl and elongate.
Best wishes with your rhodies!