Pruning Trees and Shrubs

Pruning Trees and Shrubs

Brian Jervis: Ask A Master Gardener

Sunday, December 22, 2019

Q: I need to do some trimming and pruning on our trees and shrubs. Is now a good time to do that? MA

A: Pruning and trimming is an important part of keeping our trees and shrubs healthy as long as you know when to prune and how. It can also be a little tricky because now is the perfect time for some plants and not so great for others. Here are some general tips to help.

We prune for a variety of reasons: training and shaping the plant, thinning for better air circulation and health, removal of dead branches, stimulating new growth or flowers, or to keep plants away from our homes or other structures.

One thing to remember is to never remove more than about a third of the branches. If you do a good job pruning, your work will not be noticeable. It will look natural and not like you were trimming with a vengeance. This un-natural manner of trimming can be seen all over town in what we gardeners call “crape murder” (the over-aggressive trimming of crape myrtles you see in the photo and all over town).

Here are some general rules on when to prune.

Flowering trees, shrubs and vines typically should not be pruned in the winter as many of these set the flower buds for the next year in the summer. Most hydrangeas fall into this category (except the Oak Leaf variety). If you have not been getting flowers on your hydrangeas, have you been cutting back those dead-looking stems in the fall or winter? They can be a little unsightly, but the best time to prune these is after their blooming burst in the spring so they will have time to set buds for the following year. Other shrubs that fall into this category are flowering quince, forsythia, viburnum and wisteria.

Another group is the summer-flowering varieties, such as abelia, butterfly bush or Rose of Sharon. These should be pruned in the fall or early spring.

There is also a category of broadleaf evergreen plants like acuba, camellia, boxwood, cherry laurel, holly, mahonia, nandina and photinia. These are best pruned in the spring before new growth begins.

Tree trimming and pruning is typically best left to trained professionals. I know, a lot of us consider ourselves chain-saw warriors, but there is a difference between cutting up a branch that fell to the ground and successfully cutting that several hundred-pound branch off a tree. Typically, this type of work is better left in the hands of a trained arborist. Tulsa is fortunate to have several arborists to from which to choose. To find a good arborist, we suggest you visit treesaregood.org. This is the national database of arborists. Their website will help you find a local licensed arborist who will meet your needs.

We have an extensive list of different varieties of how to trim on our website. We also have a video on how to plants that include recommendations on when and properly trim crape myrtles. You can find this and more information on our website, tulsamastergardeners.org, by clicking the “Hot Topics” button on the home page. Good luck and stay safe.

Garden tips

·        All birds need and appreciate clean feeders and unfrozen water on cold days. Place feeders close to protective shelter, if possible.

·        Be sure to keep your Christmas tree watered to keep if from drying out.

·        Light prunings of evergreens can be used for holiday decorations. Be careful with sap that can mar surfaces.

·        Newly seeded fescue will continue to grow roots and make energy if you keep them free of leaves.

Poinsettia Care

Poinsettias: How to Achieve Re-Flowering Next Season

Tom Ingram: Ask A Master Gardener

Sunday, December 8, 2019

Q: Each year I purchase a new poinsettia and each year I end up throwing it away. Is there a way to keep it until next year? CH

A: Poinsettias are our favorite Christmas plant with sales of over $250 million dollars each year. That’s a lot of poinsettias!

Poinsettias are the namesake of Joel Poinsett, the first U.S. Ambassador to Mexico, who first brought these plants north to the United States. In their native Mexico, they are a perennial and can grow 10 to 15 feet tall making a beautiful shrub. In honor of Poinsett, Dec. 15 is National Poinsettia Day which coincides with the death of Poinsett in 1851.

Believe it or not, the poinsettia has also been known by several names; such as the Lobster Flower or the Flame-Leaf Flower due to the red color of its bracts (that is what those red leaves are called). But good luck walking into your local nursery and asking where the Lobster Flowers are. OK, so enough with the history lesson, let’s get back to the question.

As gardeners we hate to just throw away a potential new member of our garden tribe, but some plants kind of nudge us to move in that direction. If you want to try and keep your poinsettia alive while encouraging it to develop those beautiful red bracts next year, here is what you are going to need to do.

1) At the first of the year you should fertilize your poinsettia with a good all-purpose fertilizer and provide it with adequate sun and water indoors.

2) Sometimes the plants can become leggy, so around mid-February, trim it back to around 5” in total height.

3) Mid-March remove the dried and faded parts of the plant.

4) Mid-May (after the danger of a freeze is over), you can move the plant outside to a place that gets indirect sunlight. Keep them away from locations that get hot-drying winds. Trim the longer branches back about 2 or 3 inches to shape the plant into a rounded bushy plant. Be prepared to replant if it outgrows its container. Continue to water and apply a house plant fertilizer at the recommended rate.

5) In late September, bring the plant indoors and place it in a sunny location. At this point the plant needs to rotate between absolute darkness and sunlight to begin developing that bright red color. To accomplish this, leave them in the sunny location each day, but place them in absolute darkness from 5 p.m. each evening and leave them there till about 8 a.m. Follow this daily procedure daily for about two months and you should you get good red bract color, typically by Thanksgiving.

Or, you could do what most of us do; enjoy them while we have them and purchase a new one each year.

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th St., or by emailing us at mg@tulsamastergardeners.org.

Garden tips

• Apply dormant oil for scale infested trees (crape myrtle bark scale) and shrubs when temperatures are above 40 degrees.

• If your roses have not been mulched, do so now. This is a good place to use those fall leaves which have been shredded with a mulching mower. Mulch not only will prevent cold damage to those plants which are susceptible but will prevent warming of soil on warm winter days which may promote premature cold sensitive new growth