A variety of factors, including water restrictions and an uncertain economy, are making people more conscious of their water use and water bills. Then there are our increasingly complicated lifestyles, which make treating for pests and diseases or replacing dead plants an unmanageable time drain. Add to that the growing desire to do our small part to help the environment, and the result is a strong movement toward sustainable gardening – both in the landscape and containers.  And creating a sustainable garden simply means using drought-tolerant and low-maintenance plants that offer season-long interest while requiring fewer chemicals and less water.

Beyond the usual suspects

Sustainable gardens don’t have to just look like cactus or desert scrub though. If you think roses are out, for instance, think again. Easy-care, drought-tolerant Flower Carpet® groundcover roses (seen above) can be a great choice for low-maintenance, season-long colour in beds or containers.

When planted en masse, Carpet Roses (which spread more horizontally than vertically and become covered with blooms) are also a great way to quickly fill in a large bed you’d like to turn into a more low-maintenance, sustainable landscape. They’re also ideal on slopes to help reduce erosion as seen below in the mass planting of Flower Carpet® Red in a California hillside planting.

There is nothing more dramatic than a sweep of one or two varieties such as ornamental grasses. Plus, beyond the visual advantages, the sound of ornamental grasses swaying in the wind adds another sense – hearing – to the garden experience. Other low-maintenance plants that are ideal for mass planting include rhododendrons, azaleas, astilbe, and hydrangea.

However, mass plantings can be a two-edged sword, since a monoculture of plants is subject to being wiped out by a pest or disease. So if you do use one plant, make sure it’s a time-tested disease- and pest-resistant variety or perhaps a native or adapted plant that has proven itself in your area.

There are also plenty of sustainable plants offering architectural interest and texture. For instance, the Storm™ agapanthus series is good for mass planting because of its sturdy, multiple flower stalks, uniform height and multiple flushes of blooms, each lasting six to seven weeks. Between blooms, Blue Storm™ agapanthus still makes a statement with its freestanding cluster of strap-like leaves.  And, Blue Storm™ is the only agapanthus that’s survived the Dallas Arboretum’s intense trials in the heat.

Or, why not try blocks of colourful or textured foliage? Perhaps you could try a tropically hued block of the red, glossy, straplike foliage of cordyline Festival™ Burgundy (sold as Red Fountain™ in AU/NZ), seen below. Not only is this cordyline extremely drought-tolerant and pest-resistant, but its basal branching, low- growing structure allows for fuller, more compact clumps and a gently fountaining effect. (It also overwinters beautifully as a houseplant for anyone in cooler climates or USDA Zones 7 or lower, so you can replant it year after year). 

Planning tips

When planning a new garden area, it’s most important to start with a site analysis, where you take the time to determine what areas of your property are sunny or shady, dry or wet – or perhaps both, wet in the spring and dry in the summer. Mass plantings are only sustainable if you choose the right plant for the right place.  For instance, plants that require partial shade for maximum performance should not be planted in a sunny spot where additional watering would be needed.  Combining plants with the same light and water requirements is key to a successful sustainable garden.

If you prefer the drama of planting en masse, you’ll need to remember that it requires buying and planting multiple plants at once, so it’s an investment of time and money. To help save money on plants, buy at the end of the season because many retail nurseries don’t want to overwinter plants and therefore sell them off at a discount.

It might also be wise, when dealing with a larger planting area, to hire – or at least consult with – a professional landscape designer. They can draw you a beautifully designed, well-scaled plan and properly specify quantities of compost, plants and mulch.

For DIYers, think about first drawing out a plan with new plants at their mature width, so you can calculate how much you’ll need in materials. If the idea of mass planting seems too risky or expensive, try planting a mix of three or four varieties—again, plants that all have the same watering, soil and other requirements. If the area is dry and sunny, for instance, try lavenders, coreopsis, daisies and black-eyed Susans. Wet and shaded? Try viburnum nudum, ferns, sambucus and sedges.

Whatever you choose, we hope the idea of sustainable gardening sticks, and that everyone out there thinks of sustainability like colour in the garden: a must-have.