Two Birds With Many Stones

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Gravel and stone function like mulch.

Fads are not necessarily bad ideas. Some evolve out of good ideas. Others are recycled old ideas that worked. The current popularity of stone, gravel and artificial ‘dry creek beds’ is probably the result of the drought. Yet, they were becoming popular before the drought. This is not their first time around either. They were popular through the 1970s and the 1950s as well.

Stone and gravel obviously do not need to be watered. Therefore, more area occupied by stone, gravel or dry creek beds equates to less area occupied by plants that want water. Such areas are not as useful as pavement or decking, but are more appealing where space does not need to be useful, and work nicely where the ground it sloped too much for pavement.

Stone around the trunks of mature trees works like an insulating mulch so that lawn grass and groundcover plants can be kept at a safe distance. Otherwise, the water needed to sustain the grass or plants against trunks can cause root or trunk rot. However, stone should not be piled so deeply that it holds moisture or interferes with aeration.

Stone is actually better than mulch in some situations. It does not decay. Stones and larger gravel are not likely to be blown or raked away, although small gravel can be difficult to separate from debris while raking. Since stone does not need to be replenished, groundcloth can be installed beneath it to prevent weeds from growing through.

Artificial dry creek beds do not need to be completely dry all the time. They can actually improve drainage in low spots that get saturated during rain. Stone on groundcloth drains better than soil or plants do. Artificial creek beds that are only ornamental should stay in low spots anyway. They look even more unnatural in high spots that water would not naturally drain to.

A few plants can go a long way in larger areas of stone or gravel, and particularly in artificial dry creek beds. If the stone is done properly and is appealing enough, the plants merely add a bit of color, form and texture, without completely obscuring the stone. Drought tolerant plants are of course more appropriate if the intention of stone is to conserve water.

Know The Time To Conserve Water

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Automated irrigation is certainly not perfect.

In the wild, plants take water when it comes as rain. Native plants and plants that are from similar climates might be happy to get almost all of their water through winter, and almost none through summer. However, lawns and many other plants want some degree of water through summer. This is why most landscapes are irrigated.

Obviously, irrigation is unnatural. The main disadvantage is that it uses water that must be taken unnaturally from natural sources, which are often, and are presently depleted. The advantages (even during a drought) is that irrigation can be applied where needed, as needed, and when it is most appropriate.

Irrigation systems can be designed to deliver more water to plants that need it, and less water to those that are less consumptive. Watering by hose can of course be similarly tailored to the plants. The volume of water applied can be increased through warm and dry summer weather, and decreased or discontinued through winter.

Automated irrigation can be set to operate very early in the morning when no one is likely to be out in the landscape. The water gets used when the need for water in the home is minimal, so fluctuation in water pressure should not be a problem. If it operates early enough, irrigation can finish before anyone gets out to see it.

Furthermore, early morning also happens to be the best and most efficient time to apply water. Less water evaporates while the air is cooler and more humid. Therefore, more water soaks into the soil. Evapotranspiration (evaporation from foliage) is a bit subdued, so plants cycle through their own moisture a bit slower.

Many plants can just as easily be irrigated in the evening. This would allow even more time for water to soak in before the sun comes up. However, the problem for some plants and lawn is that moisture lingering on foliage all night long can promote the proliferation of all sorts of fungal diseases, including mildew.

Drip and similar irrigation is still the most efficient, simply because water is applied directly, with minimal evaporation. Broadcast irrigation from lawn sprinklers, especially fine mist, is much more susceptible to evaporation. Water evaporates as it gets sprayed through the air, and as it lingers on any wet surfaces.

Eucalypti Are Innately Drought Tolerant

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Distinctive foliage provided by red ironbark.

Drought is nothing new here. There could be plenty of rain next winter and for years afterward; but eventually, there will be another series of dry winters, prompting rationing all over again. Landscapers and big box garden centers continue with business as usual. It is up to us to manage our gardens responsibly. Besides native plants, aloes, yuccas, junipers and eucalypti are four groups of formerly popular, drought tolerant plants that are worthy of more attention again.

Eucalypti had gotten a bad reputation even before they became popular the last time around. Tasmanian blue gum, Eucalyptus globulus, that was planted so extensively for wood pulp and timber throughout California, is a huge and extremely messy tree. Yet, it is still the most familiar of the eucalypti.

Garden varieties of eucalypti are much more docile. Even though they drop their evergreen foliage and hard seed capsules throughout the year, they do so on a smaller scale. The tall and elegant lemon gum constantly sheds strips of bark like the Tasmanian blue gum does, but does not get big enough to be too overwhelming.

Because they are so undemanding, and some are somewhat messy, eucalypti are best in unrefined parts of the landscape, and away from lawn. Their mess is no problem over ivy or iceplant. They are happiest where other trees might be unhappy. Generous watering actually inhibits root dispersion, and can cause vigorous but structurally deficient stem growth.

Eucalypti innately prefer to be planted while very young, even from four inch or one gallon (#1) pots. Larger (and more expensive) trees, such as boxed trees, take so long to get established that they get passed up by faster growing tiny (and less expensive) trees. Because they are sensitive to confinement, eucalypti are unfortunately rare in nurseries.

The online catalog of Annie’s Annuals and Perennials, which is famous for excellently weird and undemanding plants, features lemon flowered mallee, red capped gum, silver princess gum, bell fruited mallee and fuchsia gum, all in four inch pots. The bell fruited mallee and fuchsia gum are like large but airy shrubbery that do not get much taller than the eaves.