Does Your Swale Need a Make Over?
The South Florida “swale” or tree lawn/parkway as it is called in other parts of the country, describes the green space between the sidewalk and the street.
Swales are designed to hold excess water from rain events, allowing the water to percolate back down to the water table, instead of running off into the streets.
Swales serve an important role in our Florida Friendly Landscapes. They often include street trees and turf.
However, this time of the year many so-called green spaces are anything but green. The rains have ended and the toll taken by weeds, landscape maintenance workers who cut the lawn too short, competitive tree roots, grubs and chinch bugs or diseases such as Take-All-Root Rot or Lethal Viral Necrosis leave many swales brown and barren. What to do?
Think outside of the typical swale for solutions.
If tree roots are numerous or quite large, give up trying to grow turf. Instead, consider mulching the area or planting it with a more shade tolerant ground cover.
Some good choices would be: Muhly Grass, Quailberry, Ferns, Liriope or Asiatic Jasmine. A limited number of tree roots can sometimes be cut and removed, but be careful not to stress the tree. Cutting too many roots can lead to tree decline and/or instability. With a more shade tolerant ground cover in place, tree roots will thank you for a more friendly environment without mowers and weed eaters frequently injuring them.
If there is enough sunlight and reliable irrigation you may want to re-sod the area. Here are some important considerations:
- Make sure that irrigation coverage is adequate. If not, repairs or extensions may be necessary.
- If insect pests are still present, control them with an insecticide labeled for turf.
- If Lethal Viral Necrosis is suspected, submit a sample to UF/IFAS Extension Lab for diagnosis. If confirmed, do not replant with St. Augustine ‘Floratam’. Instead, replant with a different turf grass that has some tolerance to this disease.
- Prior to laying new sod, prepare the area by raking off all dead turf, weeds, fallen leaves and other debris (see photo) It may be necessary to remove several inches of accumulated thatch, dead stems, leaves and roots.
- Top dress the prepared area with a pre-packaged soil amendment that has high organic matter content (see photo). Make sure to rake it to achieve a uniform and level surface.
- Lay fresh, high quality sod snuggly end to end, covering the barren area (see photo). If the area is irregular in shape, sod can be cut to fit using a sharp spade or similar cutting tool. Make sure you do not cover over irrigation pop-ups.
- Once the sod has been put down, water it thoroughly at least once a day for the first seven to ten days. It needs to be well rooted in before reducing the water. This can be done with either a hand held hose (see photo), above ground sprinkler or in-ground irrigation system. If you are relying on the irrigation system, it should run for about 20-25 minutes. Water early in the morning. Do not water during the evening hours as this can create long periods when the grass is wet which can lead to fungal problems.
- Avoid applying any fertilizer until the sod is well established – 2-3 months after installation.
Swales are the first thing people notice when they drive by a home.
With these simple steps in mind, you can re-green your swale and improve the appearance or your property and neighborhood.
Written by: Michael Orfanedes, Commercial Horticulture Extension Agent in Broward County, and Donna Castro Education Specialist