HYDRANGEAS ARE BELOVED SHRUBS in todayï¿½s gardens. A variety of shapes, sizes, and flower colors is available to suit almost anyone’s individual taste. One of the toughest, most consistent, and easiest to grow is Hydrangea paniculata “Limelight,” the panicle hydrangea.
GROWN FOR THE FLOWERS, this shrub has 6-12-inch cone-shaped panicles of flowers that start out white, turn chartreuse, then pink to darker rose, and finally tan to brown for the winter. Flowers cover the entire plant and they bloom on new wood or the current season’s growth, so you are guaranteed flowers every year no matter how bad the winter. Flowering begins in mid-summer and a showy display of evolving colors remains until fall, making a long bloom season. Flower color is not affected by soil pH like with the bigleaf hydrangeas.
PLANTS CAN GROW 6 TO 8 FEET TALL and 6 to 8 feet wide. They are often trained into a tree form for use as a small tree instead of a shrub. Full sun to part shade and moist but well-drained soil are preferred, but they are tolerant of less than optimal conditions.
SIMPLE, DARK GREEN, AND SERRATED LEAVES can be up to 4 inches long and will turn shades of red for the fall, adding to its overall beauty. This shrub can be grown without any pruning or can be pruned in the winter to manage it at a small size.
For lowest maintenance, plant them 6 feet apart and let them grow. You will be rewarded each summer with an amazing flower show.
ASK THE GARDENER
by Angie McManus
Q Our river birch has leaves that are turning yellow and falling off. Is this a disease or drought issue?
A There are a few different reasons why the foliage on your river birch (Betula nigra) is turning yellow. The most common reason is a result of heat and lack of moisture. Whether a new planting or part of the landscape for many years, this tree is a water lover and this growing season has been hot and dry.
Chlorosis is another possibility; this iron deficiency occurs when the soil is too alkaline for the plant to take up the iron or it might just not be available at all. If the yellow leaves have green veins, then chlorosis is a possibility.
Thankfully, river birch does not have many insect or disease problems, but birch leaf blight is a fungal issue that can cause the foliage to develop black spots with yellow rings around them. Infected foliage will eventually turn pale yellow and fall from the tree.
It is important to have the problem diagnosed so you know the right treatment options. You can take samples to your Cooperative Extension office (find your county office online at www.ca.uky.edu/county). This way you will know exactly what you are dealing with and how to treat it.