By Diane Brown
The usual August heat wave leaves plants in the garden and landscapes looking a little tired and thirsty. Although sprinklers work well for lawns, they aren’t the best solution for gardens and landscapes. Soaker hoses, drip irrigation and watering bags can help make the task of watering easier.
When plants are stressed, they are more susceptible to attack by insects and disease. An important way to keep them healthy is by supplying adequate water. Wilting leaves or yellowing foliage are common indications that plants are suffering from a lack of adequate water. When it’s 90 degrees F out, and everything in your yard and garden needs watering, lugging buckets and refilling watering cans is a painful reminder that water weighs eight pounds per gallon.
In garden areas, soaker hoses and mulch are key to keeping the soil moist without spending a fortune on your city water bill. For best performance, soaker hose shouldn’t be more than 100 feet in length. Place the hoses an inch or two from the base of the plants. In vegetable gardens, you can run them in a straight line; in flower beds, you may have to snake them through the beds to get them close enough to the base of the plants. In landscape beds, they can be covered with mulch to hide them, but don’t bury them in the soil.
The steady drip of water seeping out through tiny pores in the rubber soaker hoses enables the water to get to the root system instead of being lost to the atmosphere. Since the hose rests on the ground, the foliage stays drier, reducing the risk of fungal leaf diseases that can occur with overhead watering.
Light-colored mulch, such as straw, will help to retain moisture and keep the soil cooler. Clean straw in the rows between garden plants and a layer around plants in the rows will also help reduce competition from weeds.
How long does it take to water using soaker hoses? It depends on the water pressure and hose diameter. For example, at water pressure of 40 psi using 5/8-inch-diameter hose, it takes about 100 minutes to deliver half an inch of water. Plants will usually need between 1 and 2 inches of water a week. Timers can be purchased to hook up to the outdoor faucet used for watering.
Soaker hoses work best on a relatively flat surface. They do not work especially well on slopes.
If you have a sloping surface, drip irrigation will be a better solution. Drip irrigation systems are made for home use. They are a bit more complicated than soaker hoses because they have more parts to assemble, including the tubing, emitters and filters to keep the lines from clogging.
Leaf scorch is a common landscape problem during the typically hot, dry weather of August. Recently planted trees and trees surrounded by extensive areas of pavement are especially susceptible to drought injury.
Newly planted trees don’t usually have a very extensive root system; they need lighter but more frequent watering. Be sure to keep them well watered during periods of drought. Irrigation bags are a good method for watering trees, but they are not self-refilling.
For them to work, you have to fill them with water regularly. The upright, green irrigation bags typically hold about 15 to 20 gallons of water. Depending on your soil type, you may need to refill them once or twice a week. Some types of bags can be zipped together to provide enough water for larger trees.
Brown is a consumer horticulture educator at Michigan State University Extension. She can be reached at [email protected].