Now is a great time to prune summer-flowering shrubs like cotoneaster. There are basically two methods of pruning them. The first is called renewal pruning. Here you cut out about 1/4 of the tallest and largest branches (canes), removing them 2 to 4” above the ground. Each year you would repeat this process so that after about 4 years, the oldest branches will be 4 years old. Keep on pruning like this, “renewing” the shrub each year. This will help to maintain smaller plants and therefore a shorter shrub.

The other method is called rejuvenation pruning. This is a good method to clean up a really overgrown bunch of shrubs or hedge. Once again, cut the branches down to 2 to 4” above the soil line. But in this case, you would do it to all of the branches. This does sound drastic, but people are amazed that by the end of the first summer, the plants have grown back up to 2 to 3’ in height. Once the shrubs get to the height you want, you can then start the renewal pruning process described above.

You can also begin to sheer the shrubs if you have them planted as a continuous hedge. Remember that a properly sheered hedge is widest at the bottom and tapers toward the top. This way the plant’s twigs will have maximal sun exposure from top to bottom. But, if fire blight is a concern, then see the information below.

If fire blight is a problem in your plants, and it too often is in cotoneaster, then you need to modify your pruning process to get rid of as many of the infected branches as you can. This bacterial disease can destroy a cotoneaster shrub in just a few years. It can be spread by splashing rain or sprinkler irrigation and by pruning a diseased stem, then pruning a healthy stem. It causes a darkened, reddish-black almost burnt appearance to the stems often causing the tips of the stems to curl over like a Shepard’s crook with the dried up, brown leaves still attached. Any stems that show this kind of damage should be removed, cutting the stems at least 6” below any sign of the sunken, discolored lesions. If possible, prune healthy branches first, then go after the branches that have the fire blight, to avoid spreading the disease to the healthy branches.  Consider repeatedly dipping the pruning tools in Lysol, rubbing alcohol or a 10% bleach solution between branches to disinfect the tool and reduce the chance of spreading.