Monday, March 4, 2013

Prune Like a Pro

My latest newspaper article:

Azaleas, magnolias and Indian hawthorn with no spring flowers, shrubs with gaping holes and naked bottoms, trees with multiple trunks or few interior branches are all cause for concern. But before you pull out the pruners, chainsaws and loppers, your plants will be happier if you learn the basics of proper pruning. Here are some things you can do to prune like a professional.

First of all, it’s about timing. Pruning done in the late fall or early winter stimulates new growth, especially if we have a mild winter. This new growth is very tender and is easily damaged, even by a light frost. It is much better to wait until spring bud-break before pruning. This will reduce the risk of cold damage.

Plants that produce their flowers on last year’s growth, such as azaleas, magnolias and Indian hawthorn, must be pruned after they bloom in the spring, and pruning must stop after June when the new buds start to form.

Plants that produce flowers on this year’s growth are usually pruned while still dormant (January/February), or just before the spring growth flush. These plants include hibiscus, allamanda, plumbago, frangipani and rose. To encourage the most plant growth, prune just prior to the first spring growth flush. To slow growth and keep plants smaller, prune just after each growth flush. Most evergreens, such as podocarpus, holly, ligustrum, juniper and wax myrtle, can be pruned anytime.

Secondly, it’s about the cut. There are only two proper cuts. One is called a reduction cut and it removes a larger branch back to a smaller side branch. The second is called a removal cut and it removes a side branch from a larger branch. Flush cuts and topping are harmful and should not be done. When removing branches that are an inch and a half in diameter or larger, use the three-cut method. This keeps the branch from ripping down the side of the trunk. This method starts with a cut on the underside of the branch about 15 inches from the trunk. The second cut is made downward from the top of the branch a few inches out from the first cut. The third cut is the removal of the stub that is left.

Thirdly, it’s about shape. Shrubs should be pruned so that the base is just a wee bit wider than the top. This allows sunlight to reach all the leaves of the plant and will thus produce a plant that has leaves from top to bottom, rather than the shabby looking shrub that has no leaves at its base. Trees should be pruned so there is only one major trunk with evenly spaced side branches. Removing all the interior branches of trees, called lion-tailing, is a harmful practice and should be avoided. Thinning is done from the outside in, not the inside out. Palms should never be pruned above the horizontal line of 9 o’clock and 3 o’clock. Another good rule to follow is to only remove a third of a plant’s entire mass when pruning.

For more information and diagrams, google “Pruning Landscape Trees and Shrubs IFAS”, “Pruning Palms IFAS” or “Disinfection of Horticultural Tools IFAS,”

For free help with your lawn and garden questions, the Pinellas County Extension Service is just a phone call or visit away. We are located at 12520 Ulmerton Road, Largo, next to the Florida Botanical Gardens and are open from 8 a.m. to 5 p.m. Monday through Friday. To speak with a horticulturist, call 727-582-2110 Monday, Tuesday or Thursday from 9 a.m. to noon or 1 to 4 p.m. on Mondays, Tuesdays or Thursdays. You can also visit our website at

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