Plant madness consumes gardeners in the months of May and June. But before loading that hot new plant on to your garden cart, give some thought as to what it needs in terms of care and how you plan to provide it. Will it be stuck into an empty spot in a perennial bed, with no thought as to its need for water? Or will it spend a couple of months in its pot, requiring daily watering, as it becomes root- bound and struggles?
Gardeners often scan the tags of new plants looking for Zone hardiness and sun requirements, but sadly overlook their water needs. And water is key to a plant’s existence. Plants can struggle along on less than optimal sun. And plants have lived for years without a drop of fertilizer. But too much or too little water can do them in rather quickly.
Xeric plants, those that once established require little or no supplemental water, suffer when sited next to moisture-loving neighbors such as roses and hydrangeas.
This overwatering often results in deadly crown rot and other diseases for these water-wise plants. Tall sedums, such as ‘Autumn Joy’ and ‘Matrona’ spilt apart and flop over, a condition known as lodging, when given too much water. Lavender may thrive in its first season in the garden, but fail to make it through the winter if planted in humus-rich, moisture-holding soil.
Grouping plants according to their moisture needs not only helps them to grow better, it also saves time, possible replacement costs and water—a key element to sustainable gardening.
The technical term for this technique is hydrozoning, which has been practiced in the west for decades. Many western municipalities require landscape designs to include water-conservation materials, drought-tolerant plants and a plan for hydro-zoning.
Hydrozone your garden by separating plants according to their needs for water. Here, Sedum
‘Matrona’ fronts a stand of lavender (Lavandula) as part of a drought-tolerant perennial planting.1
Including regionally appropriate native plants in the landscape is considered by many to be key to sustainable gardening. But they are only effective as water savers if planted in a hydrozone with other water-wise plants.
How water is applied to the garden is also part of the equation. Watering with a hand-held, hose-end sprayer may be mentally satisfying, but it’s a poor method of watering. Few have the patience to stand for the time it takes to deeply water an area.
Drip irrigation, using soaker hoses or drip emitters, is considered tops for efficiency, effectiveness and conservation when installed properly. Water applied slowly seeps into the ground with a minimum of wasteful runoff.
Overhead watering with a sprinkler is best for large areas but should be done early in the morning to reduce evaporation and allow leaves to dry before dark, when diseases tend to strike.
Hand-watering with a watering wand is recommended for containers so water can be carefully directed to the surface of the soil. The diffuser breaks up the water flow so as not to wash the soil from the pot.
In the case of drought, a root feeder is an effective and water-wise tool for trees and shrubs.
A 3-inch layer of mulch insulates and protects the soil while holding precious moisture in the ground. Organic materials such as bark, wood chips and leaves provide protection for moisture-loving plants and they enrich the soil as they decompose. Pea gravel, fine crushed stone or pine needles are good choices for xeric gardens.
Less is more when it comes to feeding landscape plants. For moisture- loving plants, humus-rich soil, an organic mulch and a bit of compost is about all they need. Xeric plants thrive in lean soil and Mother Nature takes care of the rest.
1. Photo courtesy of PerennialResource.com
2. Photo courtesy of Jo Ellen Meyers Sharp
3. Photo courtesy of Matevz Likar/Fotolia
From State-by-State Gardening May/June 2013.