From the Greek – xeros meaning ‘dry’, a method of gardening that uses minimal water.

No plant can exist without water but once established, some are very adept at existing with very little.

Gardening is working with plants but much of what many assume to be dryland gardening is hard landscaping. We frequently see city lots covered with small rocks, gravel or large boulders, or artificial turf interspersed and pocket planted with the odd shrub or two. This type of landscaping may require less water or very focused water but there are implications in terms of the environment.

If a cool environment around the house is wanted, landscaping in this way will not help to achieve that goal. Rocks and gravel absorb heat and gradually release it overnight but in peak summer temperatures much of that heat is retained and transferred to the soil beneath. That is not good for the soil food web or the heat of your house and surroundings. Neither is a rocky surface fun to sit on or weed because however the rocks are prepared, weeds will eventually creep in. Removing gravel, rocks and boulders is also not easy, cheap or fun. Using a mixture of rocks and coloured bark or other material may work for a while but it is not easy to stop the materials from mixing and losing the original effect.

Gravel surrounding a firepit for safety reasons is still a permeable and walkable surface.

So what to do? If less plants are desired because of watering restrictions, better to have a water permeable surface with tree canopy to cool the area. Water permeable is important because as water evaporates, it cools. Allowing natural precipitation to be absorbed into the soil structure prevents it running off hard surfaces and into storm drains. By being absorbed into the soil it will sustain and feed the roots of any trees or existing plants. Once a suitable tree is established, deep watering one tree once in a while is a lot easier than watering pockets of plants frequently. Water permeable surfaces might be grass, clover, pavers, decking, or flagstones planted with thyme or other ground covers. Water permeable blocks for parking areas or general landscaping are also available and low maintenance, as grass grows naturally through them without forming a traditional ‘lawn’. Pots in summer can provide colour and fitted with drip irrigation make life a lot easier.

Wherever planting is used in a xeriscaping situation, use plants that will withstand dry conditions

Plants that will survive with little water, once established:

• many species of perennial Bachelor Buttons (Centaurea), Lovage
• those with long tap roots or water storing, tuberous roots and bulbs, Iris, Peony, Horse Radish, spring bulbs.  Gaillardia, Baptisia and sea Holly are all examples of plants with long tap roots that grow deep into the soil. Grasses have widespread roots to collect water.
• those with flesh water storing leaves, Hens and Chicks, Portulaca, Prickly Pear
• those with grey leaves – the grey reflects the sunlight and heat.  Artemisias, Lambs Ears, Sages
• those with hairy leaves – the hairs trap moisture and prevent transpiration (evaporation).  These plants are often also grey in appearance, Artemisias, Lambs Ears, some Sumacs, many herbs
• those with a high concentration of volatile oils which protect from water loss, frequently with highly scented foliage. Herbs – Thymes, Oregano, Sage
• those with far reaching surface roots which trap any water that falls, Spruce Trees, Sunflowers
• those with many leaves which all funnel the water to the roots. Some Ornamental Grasses, Blue Oat Grass, Fescues

Plants that survive really well in dry conditions will have several of these attributes.  A green lawn is not one of them! A cool water penetrable surface is a difficult one to achieve unless the tree canopy is good and large but by considering surface materials carefully and how much lawn is required a xeriscape garden can be achieved without covering all of it in rocks.  

For trees that will tolerate drought and offer shade look to native trees such a Manitoba Maple, Acer negundo. Many will call it a weed tree but it is large, offers massive shade, grows relatively quickly and is tough. Amur Maple or Ginnala Maple, Acer ginnala is a much smaller ornamental but another great drought tolerant and pretty shade giving tree. Lindens, Tilia  especially have proven themselves in municipal and home garden situations and are probably my favourite for fulfilling the shade and drought tolerant criteria.  It is very important to water any tree until established and a good root system has formed.    Many conifers will tolerate drought but are often too large for a small garden and are not a fire smart choice as their oils are very volatile.

Use of mulch in planted areas is very effective at helping to retain moisture and prevent weeds but it needs to be 2-3inches thick. Some plants do not thrive with too much mulch as their roots become deprived of oxygen the natural soil balance.       

There are many materials that can be used for mulch.  Fine bark chips, compost, even newspaper in a vegetable garden will work. If you are a gardener like me that plays with my plants regularly, moving them around, putting in new ones thick mulch does not work!

Examples of bark mulch, water permeable low maintenance surface with pots, water permeable surfaces with tree canopy and pots.

When watering, water well, deeply and only occasionally, once plants are established. This will encourage roots to grow deeper and wider. Soaker hoses on timers work well as water is released directly into the soil. Directing gutter water into planting beds or into barrels are also water wise techniques to use.