Pensacola News Journal

For:  Saturday, Nov. 22, 2003

By:   Daniel E. Mullins

        Extension Horticulture Agent

        Santa Rosa County

 

Resist the Urge to Prune Tender Shrubs to the Ground Each Fall

 

            Fall “Whack Back” pruning is unfortunately beginning in landscapes all along the Gulf Coast.  The dictionary definition of “whack” is a smart or resounding blow, and this describes the effects of fall pruning on certain subtropical and tropical plants.

            This habit of cutting plants to the ground each fall is limited mostly to those species which are less winter hardy in North Florida.  Examples of these are Hibiscus, Pentas, Lantana, Allamanda, Cassia, rice paper plant, butterfly bush and shrimp plant.  It’s true that some degree of cold damage occurs almost every winter, but cutting the tops off ahead of time weakens them and can greatly reduce flowering the following season. 

            Evidently, when heavy fall pruning is done, there is the assumption that all of the past season’s growth is going to freeze anyway.  There are a couple of important reasons to withhold pruning.  First, all of the tops might or might not freeze back, depending upon how low the winter temperatures go and how rapidly that they fluctuate. 

            Any live, above ground parts that do not freeze contribute to the vigor of the plants the following spring.  This means stronger spring growth and an earlier flowering cycle since the plant is not required to re-sprout below ground.

            Delayed pruning also gives plants the opportunity to go through some physiological changes that are important.   With the approach of fall conditions they can move food or stored energy down the plant and store it in the lower parts and crown. 

            In short, the sudden removal of the entire top of a tender Hibiscus, for example, interrupts this process.  Since the plant did not have time to react to lower temperatures, including frosts and freezes, a weaker root system and crown would be left to survive the winter.

            A better practice for cold sensitive flowering plants involves waiting to let things run their course.  Blackened and brown stems can be gradually removed a few days or weeks after each freeze.  Then, just prior to spring growth a final pruning can be done to remove remaining dead branches and shaping any live growth that survived the winter.

            Fall “whack back” pruners will be surprised to find that many of these plants survive the winter with less than expected damage and an earlier start in the spring.

 

Question of the Week:  I have tried to grow spinach in my vegetable garden for several years without success.  Seed germination and growth is poor.  What am I doing wrong?

Answer:  Your problem might be due to the seeding date.  The optimum soil temperature for spinach seed germination is somewhat cooler than for most vegetables.  The range for germination is 35 to 75 degrees, with 68 degrees F. being optimum.

            Apparently, some gardeners are planting spinach seed too early in the fall when soil temperatures are too high.  The recommended planting dates for North Florida are during October and November.  Try planting seeds again by the last of this month.  Recommended varieties of spinach for our area include:  Virginia Savoy, Melody, Bloomsdale, Longstanding, Tyee and Olympia. 

            Though rarely found in Florida gardens, spinach lovers should try Malabar or Ceylon spinach.  It is also known as vine spinach.  Though not a true spinach, its leaves which form a vine, resemble spinach and are used in the same way.  Unlike regular spinach, it is grown during the warm season.