Neil Sperry

Neil Sperry: Pruning pointers for summer gardens

Flower buds should be removed on plants like Aussie purple basil.
Flower buds should be removed on plants like Aussie purple basil. Neil Sperry

It’s kind of crazy how much pruning Texas gardeners have to do in early to mid-summer. This is an important time to trim many of our most popular plants. Here are a few of the most important of them.

Blackberries

Once a blackberry cane produces fruit, it will never bear fruit again. It’s critical that you cut this year’s fruiting canes completely to the ground and remove them as soon as you finish your harvest. You may also want to pinch the growing tips out of this year’s vigorous new shoots to encourage shorter, denser growth for easier harvest next year.

Elaeagnus,Abelias and Lady Banksia roses

These vigorous shrubs have odd ways of growing. They send out long, arching branches that grow far beyond the main bodies of the shrubs. By this time in the summer, the plants can start to look really shaggy, which means it’s time for the long-handled loppers to clip off the shoots. Trim them back into the main parts of the plants to conceal the cuts.

Bush roses

Remove all of the old flower stems by pruning back to the second five-parted leaf. Reshape the plants to remove errant growth.

Look at your roses closely to be sure you’re not seeing any of the fatal rose rosette virus. Knock Out roses are especially prone. If you see clubby shoots ending in browned, unopened flower bud clusters, your plants may be infected. There is no cure for this disease, and rose authorities tell us there is nothing we can do short of digging and removing the plants. Put them (roots and tops) into black plastic trash bags and send them to the landfill. Do not try to compost them, and don’t try to remove the diseased shoots selectively. If you do, you will help spread rose rosette.

Oakleaf hydrangeas

These superior, shade-loving shrubs produce large, creamy white flower clusters (actually bracts). Rather than falling off the plants after they pass their prime, the bracts turn shades of pink, then brown, and they hang on the plants the rest of the growing season and winter. Some people like to leave them on their plants, but those of us who prefer a more manicured look in our gardens trim them off as they turn brown and crisp.

Crape myrtles

Some will tell you that pruning to remove the fruit after each round of crape myrtle blooms will prompt them to flower more times in a summer. However, that’s simply not necessary. They will rebloom even if the fruit is left in place. Plus, if you start pruning off fruit, you can easily confuse the fruit with the unopened buds. They look very similar, and many people have mistakenly removed flower buds thinking they were seeds/fruit, then wondered why their crape myrtles never bloomed.

Lawn grasses

Keep mowing at the recommended height. Some gardeners think that allowing grass to grow tall helps it survive the summer heat, but this is not accurate. Tall grass quickly becomes weak grass. Mow common Bermuda at 1 1/4 to 1 1/2 inches. St. Augustine should be kept at 2 to 2 1/2 inches. Zoysias will vary with the variety.

Coleus, copper plants, chrysanthemums, Mexican bush salvia

These plants may start to get lanky and leggy. Pinch out their growing tips to encourage side branching and more compact growth.

Caladiums, coleus, lamb’s ear, basil and green or gray lavender cotton

These plants’ flowers are insignificant, yet harmful to good foliar growth. You really don’t want to let flowers develop on any of these plants. Pinch or prune them off before they start to open.

Daylilies, irises and other spring-flowering perennials

As soon as these plants finish their flowering, remove spent seed heads. Leave green foliage in place. It’s important in nurturing the plants to produce stronger roots and a better bloom in 2016.

Shade trees

Remove dead and damaged growth at any time to prevent or stop decay from developing. You might also consider removing one or two low-hanging branches from trees whose shade is choking out turfgrass below, but do not prune so much that the tree becomes misshapen. Cuts should be made against the trunk or other limbs, leaving only a 1/4-inch piece of the branch collar in place. If you leave stubs, they will not heal properly and decay will set it. Pruning paint is not needed for most types of trees.

Oaks

If you have need to prune any type of oak, the suggestions made for general shade tree pruning above will apply with one major exception. Wait until mid-July to start pruning. The oak wilt fungus becomes inactive in the extreme heat, allowing you to prune oaks more safely from summer until the middle of February. Avoid pruning oaks from late February until it gets really hot in July. Seal all cut surfaces with a light aerosol coating of black pruning paint to prevent entry of the fungus into the wood.

Neil Sperry publishes Gardens magazine and hosts “Texas Gardening” from 8 to 10 a.m. Sundays on WBAP/820 AM. Reach him during those hours at 800-288-9227. Online: http://neilsperry.com.

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