- A good rule of thumb is that plants in the ground need about one inch per week of water. Translating that into gallons means a plant growing in about 1 square foot of soil needs a bit more than half a gallon of water a week to equal 1 inch, so a 4 ft x 8 ft bed will need about 20 gallons of water a week.
- Water thoroughly and deeply each time and to allow the soil to dry out between waterings. Deep watering will allow the roots to grow deeper, where they are less likely to dry out, and will better anchor the plant. Light, surface watering wastes water because the water never reaches the root zone of the plants, and the moisture evaporates rapidly from the top inch of soil. A good way to tell if your plants are receiving enough water is to dig down a few inches, using a trowel. The soil should be moist at least 3 or 4 inches deep. Planting drought-tolerant plants (which we recommend) reduces the need for frequent watering, but the principle of deep watering still applies.
- As the weather dries out, your container plants may need daily watering, especially if the pots are exposed to the drying sunlight. Push your finger into the soil in your container plantings at least once a day to feel for moisture and be certain that plants are getting enough water. Apply water until it runs out the drainage holes.
- Do your watering during the morning hours so that the leaves can dry off before the hot sun hits them. Only water in the evenings if the temperatures are warm enough to ensure that foliage dries before temperatures drop at night, because wet foliage increases plants’ susceptibility to fungal and bacterial diseases.
- Continue to improve the quality and texture of your soil by adding organic matter at least twice during the growing season. Soils high in organic matter maintain a much better moisture balance. An easy way to incorporate organic matter is to spread homemade or purchased compost on your planting beds in the spring and to use organic mulches, like shredded hardwood bark or leaf mold, year-round.
- If a water shortage is expected, let your lawn go dormant, and water it as seldom as once a month. Once the rains return, the lawns will return to their active, green state. Raise the cutting height of your mower, so that the taller grass can help to cool the roots and preserve the soil moisture.
- I found many online resources with advice about watering, including most state university and county extension websites. One informative page is http://gardening.wsu.edu/library/lanb002/lanb002.htm
Author, Judy Diorio
Judy's Blog is written by Blackridge's gardener-in-residence, Judy Diorio. Judy has lived in Blackridge for 25 years, and writes the BGC's "In The Garden" column for the Blackboard. She has studied horticulture and landscape design and is currently preparing to be a Pennsylvania Certified Horticulturist.
Allegheny Co Extension--Hort
Arboretum at Penn State
Audubon Soc of Western Pa
Birds and Blooms
Longue Vue Gardens
NYT--Gardeners and Gardening
Organic Gardening Magazine
Pittsburgh Parks Conservancy
Pittsburgh Botanic Garden
Post-Gazette--Home & Garden
Royal Botanical Gardens
ScienceDaily--Plants & Animals
US National Arboretum
Western PA Conservancy
Wildlife Resource Council