By Linda Peacock, Master Gardener, SCMG
Over 1/3 of residential water is used outside in the summer. We all need to use water in our gardens. Regular watering is necessary for any new plants that need establishing, vegetable plants, lawns, annual plantings, and containers. All this watering can be a challenge if you live in a city that has water restrictions during the summer months or if you live on a rural property and depend on a well. So where else can this water come from? Surely since the summers are getting hotter and drier the rain won’t be enough – are there ways to harvest the rainwater for our use? There sure are! If it falls on your property its yours, let’s learn how to harvest and use it.
Xeriscaping is a term that is used a lot, but what does it really mean? It simply refers to water-efficient gardening. A water-wise garden can use less than ½ the water of the usual garden. Xeriscaping takes many forms, it can be a perennial garden that uses organic mulch, a dry creek bed, a wildflower meadow, terraced patio, a rain garden, or a bioswale. Creativity can solve most problems!
Roofs from houses, garages, or sheds can produce hundreds of gallons with each rainfall.
Rain barrels will collect and hold 40- 50 gallons each. There are even flat-backed ones to save space in small areas. You can also join two or more together. Platforms are available to place them on, allowing easier watering can or watering hose use. Water sails are also an interesting way to collect water. Place them close to where you will use the water for ease of use. Many municipalities offer rain barrels for a reasonable price each spring.
When collecting water, we need to consider mosquitos, here are a few facts. Mosquitos lay eggs in standing water. Create water movement, and they will not lay their eggs. Add a few drops of vegetable oil to break the surface tension of the water. The larvae can not hang onto the surface, and they drown. It takes 4-7 days for the full-grown adult to emerge. If water stands for only a day or two, they cannot develop.
Good Cultural Methods to Use Your Water Wisely:
Use plants that will suit your conditions. Once they are established drought-tolerant plants require very little water.
Plant native plants, they require less water and nutrients, are hardier, attract pollinators and look beautiful. Many prairie grasses and wildflowers have roots that can travel up to 20 ft into the soil to find water.
Take care of your lawn. Cut lawns to 2.5 to 3 inches high to promote deeper root growth. Leave the clippings on the lawn, they are 80% water and will shade the soil. This means less water needed and less weeds. Limit your watering to 1 inch per week, this also promotes deeper root growth. You can use a rain gauge to help you monitor the amount used. Use a timer so that watering can be done when the water won’t be lost to evaporation. Don’t be afraid of a yellow lawn in the heat of the summer – it is the typical dormant period. The lawn will green up again as soon as the weather cools. Mow later in the day when the grass is dry, losing less water to evaporation. Overseed using more drought tolerant grass seed. Kentucky bluegrass, fescues, and ryegrasses do better in wetter climates. Water your grass separately from your garden. It is most efficient to water the lawn with a sprinkler, it is not the most efficient way to water your garden.
Water perennial gardens with drip irrigation or soaker hoses. I have approximately 50 rose bushes scattered around my perennial gardens and some in a dedicated rose bed. These roses need 1” of water or the equivalent of 2 gallons per plant each week. It is best applied at ground level to avoid wetting their leaves. I have a small drip irrigation system that uses shrubblers that divert the water to the roots, where I want it. Less water is wasted through less evaporation and less runoff, and the roses do well even if they look dry between waterings. I have made a point of planting more native plants in the gardens to protect our native wildlife and ensure the need for less water. I try to choose the roses I grow this way as well. There are many roses in the Explorer, Parkland and Artist series that are Canadian bred for our climate and need less overall maintenance.
Add compost to your soil. When 1% of your soil is organic matter, it allows your soil to hold up to 200,000 L/ha more water.
Use mulch to keep the water that falls onto your soil from evaporating. A pond will evaporate 1” per day the same thing happens in your soil we just don’t see it happening. As the mulch breaks down it will add organic matter to your soil.
Cut back any dead foliage, chop it up small and leave it where it falls adding to your mulch. It is best if you do your cutting back in the spring. Leaving the garden intact in the fall allows insects and bees to overwinter in some of the plant stalks and leaf litter. Cut them back in the spring after any overwintering insects and bees have emerged to protect their natural habitat.
When planning your annual and container plantings, use the right plant in the right place. Once they are established, they will not need as much water. When you water, make sure you water thoroughly not just the top layer. Consider using succulents such as Portulaca in your containers. Annual containers typically need to be watered each day to thrive. However, many newer kinds are being bred to handle drought conditions. Places such as the University of Guelph have trial gardens that test the hardiness of these annuals. Leave lots of room in your containers for root growth, provide good drainage through drainage holes – gravel in the bottom of the container does not add drainage. Do not use diapers or other absorbent materials in the bottom of the container, they will wick moisture away from your plant roots. Add compost to retain moisture and nutrients in the soil.
If you have a wet area in your yard plant a tree, a mature tree can soak up 80 gallons of water per hour/ 2000 gallons per day. If you have low spots, actual puddles, or erosion pathways in your yard you could consider creating an attractive bioswale or rain garden. Both will prevent runoff from your yard. Runoff water ends up in our streams and lakes from the storm sewers in a city or from ditches in the rural areas. Remember when planning for any project call before you dig!
Example of a rain garden:
