Will we have another dry growing season?

Before you replace your yews with yuccas, there are ways to make your landscape drought-tolerant.

The most important first step is soil testing. Penn State soil-testing envelopes are available at County Extension offices. The results tell you what nutrients you need and how to adjust your pH.

Plants that have adequate minerals and the proper pH are less stressed and, therefore, cope better with drought.

Before any new planting, it’s smart to add three to four inches of compost or other well-rotted organic material into your garden beds and work it into the top 10 inches of soil.

Compost is porous, meaning it has lots of tiny spaces to hold water and air. This keeps the soil moist but not waterlogged.

It’s more difficult to add organic matter to existing beds and under trees without disturbing the roots of older plants, but you can gently work some in over time.

Covering those beds with two to three inches of organic mulch will also go a long way toward holding moisture and regulating temperatures, and eventually it will decompose and get incorporated into the soil.

Mulching around trees has the added benefit of preventing grass and weeds from growing near the roots and competing for water.

Once you have your soil in good shape, what plants will not need much water?

There are many reference books on drought-tolerant plants, but the first place to look is in your own garden.

Probably not everything in your yard did poorly during the last drought. Think back to what performed well.

Drought-tolerant plants have survived over time because their roots or leaves have evolved some type of adaptation for low moisture conditions.

Many such plants have long taproots, which allow the plant to reach deeper into the soil to find water. Members of the pea and poppy families, like the California poppy, or some members of the carrot family, have this adaptation.

Others have a fleshy root which can store water and protect the plant from low moisture conditions such as daylilies, red-hot poker and all members of the lily family.

Leaf structure also tells a lot about a plant’s ability to survive drought. Successful varieties may have small, divided or needle-like leaves that cut down on the surface area for evaporation.

Leaf surfaces may also be covered with numerous fine, white hairs, which give the green leaves a gray appearance. Those hairs cut down on wind evaporation, reflect away heat and help collect moisture in dew.

Other plants have fleshy leaves and stems which store water and hold it in with a waxy coating.

The way the plant grows can be a clue as to whether it can survive low moisture conditions.

Many drought-tolerant plants stay low to the ground, closer to moisture and away from drying winds. Not all groundcovers are drought-tolerant, so do some research.

If you have a windy site, plan for future drought protection by planting a windbreak shrub border.

Finally, the way that you water your plants can help condition them to dry conditions.

Give your garden plants a good soaking of about one inch of water per week, rather than a light sprinkling every day. This will force their root systems to grow deeper to seek out water.

“Growing Green” is contributed by Diane Dorn, Lehigh County Extension Office Staff, and Master Gardeners. Information: Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-813-6613