Growing zones are U.S. Dept. of Agriculture designations to indicate average minimum temperatures. We are located in subtropical zone 9b/10a, a transition area. A true tropical plant shows distress when temperatures fall below 50 degrees. We can experience lows that will kill a tropical plant to the ground. If the roots survive, the plant will rejuvenate. All it takes is two consecutive mornings of 32 degrees, for just 15 minutes each, to severely damage tropical foliage. Because we are in this transition area, we can experience extreme swings in temperatures, sometimes as much as 60 degrees within a month’s time.
The most cold-sensitive areas of BSM are the far eastern (along Burnt Store Road) and northern (Vincent Ave.) sections. Areas closer to the harbor experience the modifying effects of Charlotte Harbor. January 2024 experienced temperatures between the 60s and 70s, however, January 2018 had a low of 33 degrees and daily highs between 49-83 – there were 16 days below 50 degrees. Those chilly mornings, especially with dampness, will create fungus on plant leaves and yellowing with some leaves dropping.
Life expectancy for our local shrubs varies from 3 – 7 years. Surprised? This is what happens –
• Our growing period is almost year-round. A 5-year-old plant here is equal to about a 10 – 15-year-old-plant grown in zones 4a-5b (Michigan) or 6b-7b (Mid-Atlantic) because their growing period is approximately a third or half the length of ours.
• Historically, we should be well into the dry season and reliant on irrigation water. The impact of high TDS (Total Dissolved Solids) in the irrigation water has damaging effects to leaves and the tiny root hairs. Some plants have adapted to living with dissolved salts (e.g. seagrape); some will slowly be negatively affected (e.g. ixora), and some will just curl up and die (e.g. camellia). Watering systems with misters or drip methods are far less harmful to plants.
• Pruning also takes its toll on our plants. Because of our long growing season, pruning occurs several times a year. It may temporarily reduce the size of the plant, but it also sends a message to grow! Producing leaves, flowers and seeds requires large amounts of energy. Our plants are constantly running marathons, month after month.
As plants age-out they become stressed, diseased and die. Replace them with plants that can better handle the salt and are better suited site-wise for the location, thereby requiring less pruning. For a list of plants meeting these requirements, go to BSM22.org, and click on Landscape Committee documents and forms.
January’s “to do” list:
Ø Ornamentals –If you’re going to plant, you must also commit to watering with your hose every other day for a couple weeks (then slackening off to a couple times a week, then once a week, etc.) Tropical palms will do better when planted during the summer months.
Ø Annuals – Plant, but take the time to prep the soil well. Mound the soil with a substantial amount of annual mix (contains vermiculite, sand and ground mulch), sprinkle with Osmocote (fertilizer) and a fungicide. Then plant your annuals. Mounding the soil will elevate the plants so they are more easily seen, keep them from getting wet “feet” and provide adequate good soil to settle their roots into.
Ø Pruning – If any plants show signs of cold damage, do nothing! Brown leaves and branches serve to protect emerging green parts from further cold spells. Even if a plant looks dead, wait until March before deciding what and where to prune.
Ø Fertilizing – Hold off fertilizing turf and other cold sensitive plants.
