Spring is the time for waterwise planting

By Pat Howell

Now that Spring is here (or is it Summer?), we all want instantly beautiful gardens to delight us, soothe us, relax us, give us more excuses to be outdoors.

Garden centers are filled with color and texture and fragrance to tempt us. The warmth of the sun and all that rain the last six months has done wonders for us and for our gardens (and trees, not to mention the farmers' joy). Even the snow 'blanket' contributed to the plants' snug winter sleep.

We all remember too well the effects of droughty summers, particularly 1999 and 2002: brown weedy lawns, sickly looking plants; and trees barely surviving the onslaught of disease and insects; while others, badly weakened by lack of water, succumbed.

We who are plant aficionados (plant nuts, in other words), do not believe we have seen the end to hot dry summers. We are seeking ways to garden better with less water.

Research has shown that trees are important to the quality of residential streets and to the perceptions people have about their neighborhoods. We prefer landscapes with trees, especially large ones. Shrubs provide the framework for the garden; annuals and perennials provide the colorful accents and help to unify the whole.

Landscape plants also play an important environmental role. Through photosynthesis plants use carbon dioxide and release oxygen. Trees and plants provide shade and cool the environment by water evaporation from leaves. They also reduce wind speed and remove dust and pollutants from the air.

It is less expensive economically and environmentally to maintain landscape plants during a drought with minimal watering than to allow the plants to die and to lose the benefits they provide. When landscape plants are replaced, they will require much more water to reestablish them than would have been required to keep them alive in the first place.

You can greatly increase your gardening success by working with nature and knowing a plant's preferred cultural conditions. Some plants actually prefer dry conditions and many more are drought tolerant. Dry gardens present exciting gardening possibilities.

Plants are wonderfully varied in their responses to drought. Over millions of years plants have evolved in certain environments (habitats). Most plant species in our region are termed mesophytic ("middle plants") in that they are adapted to neither too wet nor too dry soil conditions. But in our region, both xerophytes ("dry plants") and hydrophytes ("water plants") can thrive. Within the mesophyte group, there is a wide range of drought tolerance.

Certain plant species are inherently (genetically) more drought tolerant than others. Species that ensure greater water absorption by having deep or extensive root systems are more drought-tolerant since their roots can extract water from a greater volume of soil, particularly water that is deep within the soil, which is usually more plentiful than water near the surface during drought. To reduce transpiration (water loss), most plants close their stomates (their pores) under water stress. Wilting is a protective mechanism that results in closed stomates. Some species curl or roll their leaves to reduce water loss from transpiration.

Light-colored (silver or gray) leaves, or waxy or hairy leaves have their 'pores' below the leaf surface. They are more drought-tolerant than others.

We will continue our focus on sunny gardens next month, and provide some plant lists to get us thinking along the lines of water-wise gardens.

Dreary Discovery?

Takoma Park welcomes the new Discovery building: tenants in; the delightful 'Light Show' up and running, T-Rex in the lobby. A great neighbor.

But Easy Gardener thinks we may need to take up a collection to help the new building with their landscaping. Newly installed, it is unimaginative (this is the 'Discovery' building!); a monoculture; and there do not seem to be any drought-tolerant plants. On that large land area, surrounded by hot pavement and all the roads and traffic, the landscaping consists of many, many small, round evergreens (gumdrops in aspic), which will require considerable water to keep them alive in hot dry weather. The huge number of these gumdrops are a monoculture, meaning that if any die for any reason, there will be gaping holes in the design.

What an opportunity wasted! This prominent corner of a prominent building could have been designed as a 'model garden' to demonstrate waterwise planting: maybe ornamental grasses, purple cone-flowers, black-eyed Susans, and lamb's ears, for example.

This kind of planting would not need much water at all; would look interesting year-round (a four-season garden); could be a teaching tool (again: 'Discovery'); be less costly to install and maintain than the present planting; and represent Montgomery County's and Maryland's commitment to responsible use of water in the landscape. Easy Gardener is appalled and disappointed. (In case you are thinking this is sour grapes, be assured it is not. No personal axe to grind.)

If you know anyone in top management over there, ask them what happened and what is going to be done to fix it! If you disagree or agree with Easy Gardener, don't hesitate to let her know through the Voice. Maybe we can get a good discussion going.

Pat Howell is a Takoma Park gardener and landscape designer/garden-builder, and welcomes comments, advice, suggestions, complaints. She is available for hand-holding and answering questions through Deephaven Landscapers.