Beautiful blooming hydrangeas are loved for their large colorful flowers that fill your gardens with flowers all summer long. Even when the shrubs are not blooming, their lush, vibrant foliage adds texture and ornamental value to the landscape.
So what happens when those typically healthy hydrangea leaves are suddenly riddled with holes?
These tough plants are not easily taken down. If they are planted in partial shade with consistent moisture, they typically do not have many severe issues. However, your hydrangeas could have holes in the leaves for a few reasons. Luckily, they are all easily remedied or possibly even prevented. Let’s find out how to keep your hydrangeas looking their best!
Caterpillars
Hydrangea leaftier larvae eat hydrangea foliage and leave webbing behind.
Any type of caterpillar can be found munching on leaves. However, hydrangeas do have a special caterpillar pest called a hydrangea leaftier moth. These insects are moths that are brown and white. They lay their eggs on the branches of your hydrangeas.
When the eggs hatch, the caterpillars will use their silk to web together a few of the hydrangea leaves and eat the foliage. This protects them from any predators, including us gardeners. The good news is these leaf webbings are pretty obvious.
When you see these webbed structures on your plant, pull the leaves apart and remove the caterpillar. Pesticides are not usually effective on these larvae because they easily protect themselves with the webs. Hand removal is your best bet.
Japanese Beetles
Japanese beetles are common in gardens, especially on oakleaf and bigleaf hydrangeas.
Anyone who gardens is likely very familiar with the Japanese beetle. These bugs can be brutal in the summertime, as they are not very picky and love to show up in large numbers. Japanese beetles are more of a problem on your oakleaf hydrangeas, but I’ve also seen them on my bigleaf hydrangeas. These insects are easy to spot because their wings are copper in color. They also have a distinct eating pattern, leaving the veins behind and causing the leaves to look like lace.
The best way to get rid of your Japanese beetles is to knock them off by hand into a soapy bucket of water. You can also spray them with oil to prevent them from munching at all.
Rake Damage
Be cautious when cleaning gardens to avoid damaging delicate foliage.
If you are cleaning up your spring gardens, and raking out any leaves that have collected over the winter, be cautious when you are near any of your plants. If you rake over hydrangeas, or most other plants for that matter, you could cause some damage to the newly developing foliage. This type of damage will look like slashes through the foliage caused by the rake tines.
When removing leaves from your shrubs, use your hands when working near any delicate foliage. The foliage in early spring is tender and should be treated appropriately.
Rose Chafers
Rose chafers, small green or tan beetles, occasionally feed on hydrangeas, particularly in sandy soil.
Another beetle known to feed on hydrangeas is the rose chafer. These small beetles are less than an inch long. They are green or tan and show up in large numbers, especially in areas where there is sandy soil.
Hydrangeas do not typically like sandy soil; they prefer rich, well-draining soil, so rose chafers are not too common. However, when they are present, the grubs will eat the roots of your hydrangea, and the adult beetles will leave lacy-looking leaves similar to Japanese beetles.
Removing rose chafers by hand is the best way to kill the adults. Knock the beetles into soapy water. You can also treat your gardens with a grub killer.
Slugs
Slugs are common on hydrangeas, causing holes or ragged edges on foliage.
Because hydrangeas like moist soil and shade, slugs are commonly found on lower and younger leaves. Slug damage may present itself as holes in the leaves or ragged leaf edges. Of course, you may notice the actual slugs themselves or their slimy trails.
Slugs love decaying foliage, so keeping your garden clear of old leaves will help keep these slimy guys away. Another easy way to keep slugs out of your garden is by watering your hydrangeas at the base of the plant. This will limit the amount of moisture that is sitting on your shrub. You can also try copper tape.
Wildlife
Hydrangeas can be nibbled by rabbits or deer, especially flower buds.
Hydrangeas are not often the pick for wildlife, but they are not completely resistant to herbivores either. Rabbits or deer have been known to nibble at the edges of hydrangeas. What is most attractive to the wildlife is the flower buds.
Deer will pull at the shrub, not quite leaving holes but leaving an almost shredded look to the leaves. This type of damage is seen more frequently on young tender hydrangeas. If an older hydrangea becomes a snack for a deer, do not worry; they are resilient and will overcome the damage.
Planting deer-resistant plants around your hydrangeas will help keep the deer out of your garden. Lamb’s ear and ornamental grasses are great options that deer are not fond of. You could also spray a liquid deterrent on your plants to help keep the deer away. Products such as liquid fence work well, and you should reapply at the rate listed on the label.
Fixing Leaf Holes
Snip off the foliage with holes to remove insects or eggs.
Once your hydrangea has holes in its leaves, there is no way to make the holes in your leaves disappear. If your plant only has a few leaves with holes, you should snip them off with clean gardening shears. The reason you want to remove them is there could be insects living on those leaves or even their eggs waiting to hatch and dine even more on your hydrangea.
Plants are amazing and know how to heal themselves. If the wounds are not extensive, they will begin to heal themselves by drying out around the edges of the holes. The leaves will regenerate cells in the same way that they do when you are propagating new plants. This will help to prevent diseases from creeping in and taking advantage of those open wounds.
Preventing Future Holes
Prevent holes by maintaining a clean garden, free of weeds and debris.
Preventing holes might seem like a tricky science. However, if you know your gardens and local pests, prevention is easy. Keep your garden in good shape by thoroughly weeding and removing other debris.
Preventative sprays are also a great way to keep holes away. Using a spray, such as neem oil, can help to prevent many insects from attacking your hydrangeas.
Neem oil and other options can help keep insects away from your hydrangeas.
Final Thoughts
While holes in your hydrangea leaves can be startling to see, it is usually not a serious problem. Take the holes as a sign that something is going on with your hydrangea, and be ready to treat as needed.
