What you’ve been hearing is true - even water wise, native plants need water! In this changing climate of hotter and drier summers, growing waterwise plants and watering them smartly is a great way to reduce your impact on the looming water scarcity problem - and to inspire your neighbors to do the same. According to the EPA, outdoor water use accounts for more than 30% of total household water use and can account for as much as 60% in arid regions! Disturbingly, up to 50% of that water can be lost due to wind, evaporation or runoff. Yikes!
Effective watering is essential to maintain a functional and beautiful landscape. The best way to water nearly all plants is to practice deep and infrequent watering. This will train your plants to develop deeper and more robust root systems in comparison to light and frequent watering which trains plants to develop shallower and less robust roots. Limiting water can also increase the thickness of a plant’s cell wall, allowing the plant to retain moisture more effectively during dry and hot periods. Allowing soil to dry out will also allow for more oxygen and biotic activity in the soil.
What is deep watering?
There is no set definition for deep watering. For the purpose of landscaping with native plants in the Rocky Intermountain West, we recommend soaking the soil to a depth of 4-6” for native bunch grasses and perennials. Areas that are predominantly shrubs and trees (such as a hedge row) can be soaked up to 9”. Please note in areas with a deeper soil profile such as meadows, you will be aiming closer to 6” of soil moisture.
During establishment (first 2-3 years after planting) we recommend watering plants as much as once a week. During cool or wet periods, watering can be spaced out to every 2-4 weeks depending on your location and species mix. You can also water when plants start to look wilted.
Once established, water wise and drought tolerant plants should need little to no supplemental watering except during hot and dry spells during which watering every 1-3 weeks should be appropriate.
When to water
The best time to water is from 5am to 9am. You will lose the least amount of water to evaporation plus it sets plants up to use that water throughout the day.
The second best time is to water from 7pm to 10pm. It is beginning to cool back down again so your loss is lower, however, it does not take advantage of when plants are really using water (during the day!)
The worst time of day is to water from 10am to 5pm. You will lose the greatest amount of water to evaporation.
Go for Drip Irrigation
Drip irrigation is, at it's most simplest, a main water line with spurs of smaller lines going directly to the plants of your choosing. Although it looks complex, it's easy to set up and the most efficient way to water your garden. If you don't already have a drip system in your garden, make this your year to set one up!
Having a water wise garden also means watering wisely. Yes, sprinklers are common and require virtually no setup, but they can waste a lot of water with off target watering or too much volume all at once leading to runoff. According to one reference, “more than 90% of the water you apply through drip irrigation will be available to plants compared to only 50-60% with sprinklers.” That is a MASSIVE difference and illustrates how significant making the switch really is!
Drip irrigation slowly delivers water directly to your plants (without flinging it through the air like a sprinkler) reducing runoff, erosion, waste and even weeds. Because it waters the roots and not the leaves, it also reduces the risk of fungal diseases.
Do you like to get out in the summer? Drip systems can be set on a programmable timer to water plants both when you're at home and away. If you're like me and don't want to get up at 5am to turn the water on, this is for you!
We've partnered with our friends at Valley Irrigation to make is easier than ever to set up a drip system with our Drip Irrigation Starter Packs.
*See bottom of article for links to more detailed articles about drip irrigation.*
What about my lawn?
The same principle of deep and infrequent watering can be applied to your lawn! Daily watering of a lawn is not necessary and does not produce hardy and well-rooted plants.
Instead of watering daily, saturate the lawn deeply with 1 inch of water roughly once a week or when grass shows signs of drought (wilting.) Switching to deep watering will train your grass to develop a more robust root system. Allowing your grass to experience some “drought-like” conditions will also train the grass to develop thicker leaves with thicker cell walls which will help your grass retain more moisture.
How to measure how long to water if you already have an existing sprinkler system-
Set some empty cans with straight sides in the sprinkler zone you want to measure (something like a tuna or cat food can)
Run your sprinkler for 30 minutes
Shut off the sprinklers and measure the amount of water collected in the zone
Pour all the water into a single can
Measure the depth of the water with a ruler
Divide that number by the number of collection cans
This will provide you with the average amount of water that zone applies during a 30-minute period
Use this information to set how long your sprinkler needs to run to penetrate the soil roughly 1 inch.
If your lawn cannot absorb that much water at a time, i.e. you notice runoff, you will want to use a “soak and cycle” method. Once you determine how much water your lawn can absorb (i.e. how long you can have the sprinklers on), cap the watering time for that zone, wait the same amount of time and return again to water for the same amount of time. You may have to do this up to four times a day. Be observant! As you may have to reduce secondary and tertiary applications of water. Do this until you have applied roughly 1 inch of water.
Another important factor for establishing a healthy and functional lawn is to only mow ⅓ of the height of the grass when you mow. This reduces the overall stress your turf is experiencing. One suggestion is to set your mower at a minimum height of 2.5 inches. Remember, more foliage means deeper roots, more photosynthesis, less weeds and greater drought tolerance.