- Joan E Marsh
- Gary R Peiffer
Make every drop of water count so that everyone has enough to use all summer long.
General Watering Tips
- When watering, wet the soil to a depth of about 6-8 inches which is about one inch of water. Short, surface waterings do more harm than good by encouraging shallow roots.
- Three to five gallons of water, or less than one minute of watering with a garden hose, will saturate the root zone of a plant.
- Established shrubs can survive with one 30 second hand-watering into their root zones every 2-3 weeks.
- When installing new plants, especially large trees and shrubs, build a shallow soil bern (2-3 inches high) so that water can be directed to the plant’s root zones.
- If possible, consider doing larger plantings during the fall to early winter, or in early spring when there is more adequate rainfall.
- Trickle, drip or soaker irrigation systems provide adequate water for plant growth and reduce the amount of water used by 80-90%. Most of these systems put out 1-3 gallons of water per hour, and the water goes right to the plant’s roots where it is used.
- Before deciding how long to run your watering system, test it to see how much water it puts out over a desired time period.
- Watering plant leaves and/or stems increases your chances of pest problems, especially diseases. Also, it wastes water because very little to no water is absorbed through these plant parts.
Ornamental Plants – Watering Needs
- Many southern landscape plants can tolerate drought conditions for several days and even weeks once they are well-established (after first 2-3 years). Examples: crape myrtles, junipers, many holly varieties.
- Place large, valuable and historic trees at the top of your watering priority list. Large oaks are especially vulnerable to drought conditions and you can not easily replace 100 year old oak trees.
- Most annuals, perennials, and many shrubs (azaleas, rhododendrons) are shallow rooted and therefore have high water demands. Water them more often but limit the size of these planting areas.
- If planting color areas, such as annuals/perennials, concentrate them in containers or planter boxes, and use some water-holding polymers in your mixes.
- Water newly planted trees and shrubs BEFORE well-established mature plants. They will need at least 1-2 good waterings per week, to get rooted and to insure their survival.
- Hold off on the installation of new plants during the driest months of the year (usually June- end of August).
- Plants growing in shade generally require less water than those in full sun.
Avoid Plant Stress
- Do not fertilize drought stressed plants. Fertilizers are salts which dehydrate plant roots when the soil is dry. Encouraging plant growth during a drought is not what you want. New growth requires the use of even greater water resources.
- Drought stressed plants are weakened and more prone to pest attacks.
- If applying pesticides, follow label precautions and do not apply to a plant that is already wilted or during the hottest hours of the day.
- Avoid unnecessary pruning. Pruning stimulates new growth which again requires more water.
- Install a 3-4 inch layer of organic mulch (leaves, pine straw, etc.) over plant root zones to conserve soil moisture.
- Mulch entire root zone 6 inches out from the stem to the tip of the plant’s drip-line (ends of its branches).
- Do not pile mulch on lower stems or it will encourage rotting and pest problems such as voles.
- Most turf grasses can get by on 1 inch of water per week. This can be supplied by one to two good waterings, but you must know how much water your system puts out.
- Tall fescue grasses are not as drought tolerant and they may require up to two inches of water per week. Mowing fescue as high as possible, 2 to even 3 inches, will help shade its roots and limit drought stress.
- The best time to water a lawn is between sunset and sunrise while it is already experiencing its natural wet cycle (dew period). However, follow your local water restrictions as required and do not water until after 10 PM.
- Mow all turf less frequently during dry weather and only remove 1/3 or less of the blade height per mowing. Grass-cycle and leave those clippings on the soil to shade grass roots and provide nutrients.
- Do not fertilize drought-stressed or weakened trees.
- Water deeply by establishing soaker or drip hoses at the tree drip-line (branch tips). Provide one to two good soakings per week.
- Do not water at the base of trees or onto foliage.
- Watering leaves in the daytime can cause leaf scorch and watering leaves at night promotes leaf diseases, like mildew, and leaf spots.
- Establish natural areas or mulch islands under your larger, valuable trees.
- Leave an air space at trunks, but place mulch over as much of tree root zone as feasible.
- Limit plant competition by not over-planting in tree root zones.
Slow the Flow – Make every drop count so that everyone has enough drops to use all summer long. This is not just water conservation, it is a wise and equitable use of our natural resources.
Center Publication Number: 43