Pruning in the Summer versus Winter Pruning

Why in the dickens am I mentioning summer pruning now? Well many people still don’t know that it’s possible to prune throughout the summer. I used to have to cover summer pruning during winter pruning lectures because nobody would sign up for just a summer pruning class in the summer. In fact summer pruning may be more helpful than winter pruning. Summer pruning [especially repeated pruning] is the best way to control a tree that is growing to tall or fast. Summer pruning slightly reduces the tree’s vigor. While winter pruning stimulates new growth in the spring as it begins to leaf out.

Grandfather never lied. When he said “pruning trees in the summer is bad, especially with fruit trees—they might bleed to death” he was just repeating an heirloom myth. I know better now. Summer pruning will not cause plants to perish. In reality, summer pruning is a very valuable addition to the gardener’s repertoire of techniques (a tool, if you will) for shaping and nurturing all garden growth.

Summer Pruning’s Virtues

There are many practical aspects to summer pruning. First, it’s comfortable; you can wear shorts and a tee shirt instead of being cumbersomely bundled up. Now, pruning is spread over a greater number of months to ease a gardener’s busy spring. Since the foliage is readily visible, it’s easier to spot dead, damaged, or diseased growth; and you can watch how pruning effects light and shadow patterns.

It offers more opportunities to control unwanted growth on a tree. Mid- to late-summer is the best time to remove unwanted suckers and so-called water sprouts—those poorly-named straight shoots which tower through a tree’s crown [a.k.a., canopy] or along the top of horizontal limb—with a single pruning.

Summer pruning can allow you to enjoy bountiful flowering and then control the size of the tree. Summer pruning allows more light into the crown to add a colorful blush to ripening fruit. Pruning cuts callus-over with the assistance of active photosynthesis, sealing the wound.

Summer Pruning’s Shortcomings

Foremost, summer pruning is a new concept to many. Pruning trees in leaf makes it harder to see a deciduous tree’s winter branching pattern. The main and secondary limbs may get sunburned. [When pruning in hot summer areas, cut with discretion, leaving enough foliage to protect the main the trunk.] If you prune too late in the summer where winters are cold, any new growth will be vulnerable to some freeze damage. With fruit trees, some fruit may be knocked off if you prune on older limbs before harvesting.

Some diseases enter open pruning cuts. The fungus Anthracnose sp. causes cankers and enters cuts during fall rains in the west—don’t prune too late in the summer, allow plenty of time for a callus to form. Check the Cooperative Extension Service and its Master Gardener Program or an arborist for other diseases specific to your area.

Let me know what you think.

Visit my web site to learn about my new book on drip irrigation and other gardening books.

NOTE: The comments section at the bottom of the post has disappeared. Click on the "___ Comments" button or the title under the "Blog Archives". Thanks, Robert

Lavender Butcher?

I’m trying another bold experiment. Radical pruning of aging lavenders. I tried this two years ago and it worked. However, this plant (Lavandula angustifolia ‘Munstead’) is much bigger.

I was consumed by finishing my drip irrigation book (Drip Irrigation for Every Landscape and All Climates, revised 2009.) and traveling back-and-forth to St. Louis to help my Dad and greatly neglected my lavender plantings. They got heavy with bloom on long stems. They sort of flopped open a bit. This allowed the sun to cause tiny buds to grow far down into the plant. On stems many might call “dead” wood. (See the photo on the left after removing most of the foliage.) But far down the stems the unpruned plant sprouted many very tiny buds, as seen on the other two photos.

These tiny buds grew on a small plant I pruned this way two years ago and nobody suspects it use to look like the photo on the left.

So, the guy who wrote the lavender book (The Lavender Garden, Chronicle Books, 1998) is disobeying his own guidelines about leaving three to five healthy buds just above the mature leaves. Ha. It’s never too late to experiment.

We had a week of 90-100F days after this pruning experiment. So, I don’t know how the lavender will react. But it does look well right now. I’ll keep you posted on another blog.

(PLEASE, don’t do this in cold-weather climates. It’ll probably kill the poor plant. Just for us west-coast gardeners near the ocean to try.)

Please post a comment - I want to know what you think.

Visit my web site to learn about my new book on drip irrigation and other gardening books.

NOTE: The comments section at the bottom of the post has disappeared. Click on the "___ Comments" button or the title under the "Blog Archives". Thanks, Robert

Plants Don't Bleed to Death

Most trees don’t commit suicide by bleeding to death.

The same is true for shrubs, vines, and other perennials.

If you’ve ever had maple syrup on pancakes, you’ve eaten a bleeding sugar maple tree (Acer saccharum). Not only do the trees not die, they are tapped again the next season and for as long as 100 years. Same goes for true rubber. Slices in the bark of the rubber tree (Hevea brasiliensis ) allowed the latex sap to dribble into containers. Same tree every year for many years..

The photo on the lower left is a droplet of sap coming from a pruned Kiwi vine. I pruned the second-story vines late this year. (Rain, book to finish, coordinating an assistant, blah, blah, blah…) The end to the remaining vines dribbled like a leaky hose. For days. Now, some four weeks later, the leaves are beginning to show at the bud just behind the cut.

Why, you might ask, Kiwi’s on the second floor of my house that requires two people to lift and position the ladder? I transplanted two vines from a friend’s fence only to find out they were both females. (I have gotten as much as 25 fruits with no male Kiwi around. Figure that one out!) My foremost reason was to provide an arching canopy along the length of the south-facing wall. (I have friends with a multitude of fruit I can share.) The idea was to have a well-shaded house for our hot Indian summer days. I certainly wasn’t planning on a crop two floors off the ground. So, I prune them for shade by cutting most of the vine back to main vine and some laterals. By the end of the summer some of the vines have arched gracefully ten feet, or more, over the patio below. The cloak of the leaves is both beautiful and functional.

You can see my house in early fall in the third photo with a bit of the wall in the sun.

Please post a comment - I want to know what you think.

Visit my web site to learn about my other gardening books.

NOTE: The comments section at the bottom of the post has disappeared. Click on the "___ Comments" button or the title under the "Blog Archives". Thanks, Robert