Q. Because of water shortages, I’d like to know which plants are drought-tolerant and other things I should do to save water.
K.G., Cutler Bay
Saving water is easier than you think! Most people overestimate the amount plants require. Keeping soil constantly moist or wet reduces oxygen in the soil, which is needed for roots to function. It also leaches plant nutrients from the soil, causing nutritional deficiencies (for palms, some deficiencies are lethal). It causes stress, which makes plants more vulnerable to disease and insect infestations. It increases weed problems. And most importantly, it wastes water. Remember, fresh water is a limited resource.
Allow the soil surface to dry between waterings. This helps reduce weed problems since weed seeds need a moist soil surface to germinate. Since dollarweed is a semi-aquatic plant, it needs moist soil to grow. Dollarweed is a good indication that your lawn is receiving too much water.
You cannot tell if plants need to be watered by simply looking at the top of the soil. You need to check how moist the soil is a couple inches below the surface.
Most trees and shrubs are drought-tolerant and usually don’t require watering after they are established in the yard.
The sunny areas of the lawn, annual bedding plants, and vegetables may need irrigation during hot, dry weather. Wait until they start to wilt before watering and then water well.
Apply 1/2 to 3/4 inch of water each time you irrigate. Measure this by setting out clear plastic drink cups throughout your irrigation zone. Time how long it takes for the cups to collect that much water so you will know how long to run your system. Don’t water again until your plants start to wilt again. Grass will fold its leaves when wilted and turn an off color.
During hot, dry periods and if your soil is very sandy, the lawn may need to be watered up to twice a week, but in many areas in South Florida, this is too often. Watering once a week (or less often) is usually sufficient.
For more water-saving tips, call your local UF Extension office or read this fact sheet: http://miami-dade.ifas.ufl.edu/programs/fyn/publications/landscape_drought_recommendations.htm.
And always follow any watering restrictions and ordinances.