Garden for Dry Summers

Butterfly weed is a colorful, drought-tolerant perennial that blooms mid-summer. | Credit: PD-asters (Symphyotrichum oblongifolium): PD-USGov-Interior-FWS

How to create a healthy and beautiful landscape that will thrive in times of drought.

By C.L. Fornari

For two summers in a row the weather in coastal New England has been very dry. Although those vacationing near the shore appreciate the long stretches of sunny days, for homeowners and gardeners it’s been difficult. Wilting hydrangea leaves, browning rhododendron branches and dead patches on sunny lawns have been as common as seagulls on the beach.

Many communities were forced to issue restrictions on outdoor watering in 2016, so landscapes in these areas suffered tremendously. But even without a ban on outside water use, gardens deteriorated. There is a point when soils get so dry that even recurring irrigation just isn’t enough to deeply moisten root systems. Given a changing climate and an increasing appreciation of the need to preserve water resources, homeowners wonder how to adapt their landscapes to meet these conditions.

With thoughtful selection and placement of plants, it’s possible to have a beautiful landscape that is also water-wise and tolerant of drought. New yards and gardens can be designed with water use in mind from the beginning, of course, but it’s also feasible to make changes to existing landscapes.

Junipers do well in dry soils. | Credit: Keith Kanoti, Maine Forest Service, USA, via Wikimedia Commons

PLANT PREFERENCES

Some plants are naturally more drought tolerant than others while still others require extra water. For example, our native bayberry (Myrica pensylvanica) is able to thrive given little rainfall, but our beloved blue hydrangeas (Hydrangea macrophylla) require a great deal of water. So a water-wise New England garden starts with plants that are drought tolerant. Here are just a few suggestions.

American holly (Ilex opaca) is native to the Eastern United States and it thrives in sun or shade. In addition to being drought tolerant and having lovely bark, this holly makes a good screening plant. Birds feast on the berries in the wintertime as well.

Most junipers do well in dry soils. There are varieties that are upright, such as the Eastern red cedar (Juniperus virginiana), shrub forms and some that are low ground covers. Junipers don’t look good when they are sheared, however, so plant them where they can grow to be their natural size and shape. Eastern red cedars also blend well with large shrubs for privacy plantings in sunny locations.

Sometimes the most common of plants are overlooked when a dry garden is planted, and the border forsythia (Forsythia x intermedia) is one of those plants. Mixed in with other shrubbery, the forsythia provides a burst of yellow flowers at a time when it’s needed most. After the spring bloom, this large shrub stays attractive in dry summers.

Daylilies, which bloom in mid-summer, can tolerate drought.

Another shrub to include in the dry border is the purple-leaf ninebark (Physocarpus opulifolius). Use the cultivar ‘Summer Wine’ when it’s important that the plant stay around four feet tall, and plant ‘Center Glow’ when a taller shrub is needed.

Spireas of all varieties are cast iron in constitution and there is a size for every landscape. Bridal wreath spirea (Spiraea vanhouttei) works well in large-shrub borders, and the pink-flowering Japanese spirea (Spiraea japonica) is perfect when a shorter plant is needed. ‘Magic Carpet’ is a variety that has yellow leaves and stays under three feet, so it provides color in a water-wise planting even when it’s not in bloom.

In addition to these shrubs and trees, there are many perennials that tolerate drought. False indigo (Baptisia australis) flowers in the spring, butterfly weed (Asclepias tuberosa) and daylilies (Hemerocallis sp.) bloom in mid-summer, and anise hyssop (Agastache varieties) and asters (Symphyotrichum oblongifolium) flower in the fall. In a dry garden planted with these groups of plants there would always be something in bloom.


GROUP LIKE WITH LIKE

Throughout the landscape it’s smart to cluster plants with similar water needs together. Plants such as roses and hydrangeas that need watering more frequently can be placed together in the same area. Such plantings can be put on a different zone when an automatic irrigation system is installed. This allows them to be generously watered while other areas of the landscape are watered less frequently.

Plants like roses should be placed near other species that require frequent watering.

Mixing plants with different water needs can lead to problems along with over use of water. When junipers and hydrangeas are planted in close proximity, for example, one or the other is likely not to do well. If these plants are watered frequently so that the hydrangeas are happy, the juniper will be prone to tip-blight. But if the irrigation is set so that the junipers thrive, the hydrangeas will crisp up and die.

When water is scarce some towns restrict irrigation to hand-watering only. In this case, having plants with similar cultural desires in the same planting bed will also make it easier for the person who is providing water with a hose.

In established landscapes, plants can be regrouped gradually. The first step would be to either relocate or remove those shrubs and perennials that wilt quickly.

Nature might have taken care of identifying such plants last summer: anything that had severe dieback in 2016 might be so unattractive that it will need removal anyway.


MULCHING AND WATERING

Mulching with two inches of bark mulch or shredded wood can help soils retain water. This is especially important for those who are planting in sand. Avoid using landscape fabric underneath, however, as this prevents the mulch from entering the soil and enriching it from the top down.

Mulching is a lot like dessert: when it comes to good health, more isn’t necessarily better. An inch or two helps the plants, but a thicker layer can actually cause problems. Avoid piling mulch against stems, a practice commonly called “volcano mulching.”

By correctly combining plants, clustering the thirsty varieties in small areas, and adding a two-inch layer of mulch, you can create a landscape that is both water-wise and beautiful.

To help soil retain water, apply two inches of bark mulch or shredded wood.

Comments are closed.