Denver’s trees, lawns, and plants in times of low rainfall and water conservation

As our climate crisis worsens, water conservation in the Rocky Mountain region is the gold standard.

According to the Colorado Division of Fire Prevention and Control, fire season will begin in May and last through the summer. Our low rainfall combined with another below-average snowpack winter creates high winds that dry everything out.

According to Todd Hartman of Denver Water, being water-wise is “the right thing to do given Colorado’s arid climate and the importance of protecting reservoir supplies, rivers and streams on the Western Slope and the Front Range.” Even with our low rain, this is not time to overwater but Correctly water. The soil has a limit on its water-holding capacity. More is not always better, and can lead to wasteful behavior.

There are many ways to water-responsiblely care for your trees, lawns, and plants. Low rain periods can make outdoor plants more vulnerable to water stress because they get most their water from the soil. It is important to know when and how much water to give your plants and trees.

General guidelines for Colorado

Colorado soil is mainly clay, which absorbs water slower than sandy soils. Newer developments can cause soil compaction. This is because construction creates air pockets that make it difficult for water to move. Lawn aeration is a good way to improve soil compaction at this time of the calendar year. Aeration creates air pockets and allows water to move down to the root zone.

The general idea is that roots will develop horizontally and not just horizontally by receiving less water. This will make trees and plants more robust and better able to tap into the water tables. Trees prefer slow-drip watering, and drip lines are better for plants.

Check your local water conservation and watering regulations. Because outdoor watering is the most common use of water in Colorado, there are many options for watering.

Denver Water customers are reminded that outdoor watering will be limited to three days per week beginning May 1, and only during cooler times, between 6 and 10 a.m.

What about lawns?

Sprinkler efficiency is an important part of water conservation. It also ensures that plants and trees receive direct and deep watering.

If you have a lawn and an underground system, you can do an audit to determine how effective your sprinklers are in each season. Denver water provides tips online on how customers can conduct their own audit. denverwater.org.Fort Collins offers free sprinkler system checks, for example. Based out of Boulder, Resource Central’s Slow the FlowProvides residential and commercial sprinkler support.

Automatic systems can be set to the cycle-and-soak approach, allowing for shorter, multiple cycles due to Colorado’s hard soil. The soil absorbs more water by running water in shorter bursts, which prevents runoff onto sidewalks.

For a time period, you can cycle and soak for a set number of minutes. After that, you turn the zone off, while another zone runs. Finally, you cycle back through each zone. Determining the amount of time depends on the degree of slope, soil type, amount of compaction, and other factors,  according to the Colorado State University extension service.

Trees

Trees require water at different stages of life. Fruiting trees have higher water requirements during flowering and fruit-growing than they do in winter. Also, it’s important to consider if you watered your trees through the winter or if they are coming into spring with a water deficiency in the soil. Keep in mind that tree roots extend horizontally, often well beyond the canopy of the tree, so when watering it’s best to use a system that is broader than a direct drip. Consider sprinklers, soaker hoses, and systems that include sprinklers.

Newly planted trees are less tolerant to water stress than trees that have been in existence for a while and require more watering than those with established roots. The rooting system is key to this. A slower drip watering schedule will encourage a tree’s downward growth, which will make it more resilient in the future. Tree “gator bags” are excellent for newly planted trees as they slowly drip in the root ball area.

Container plants, raised beds and gardens

As with trees, transplanted flowers and seedlings will need more water until they become established roots. It is better to use drip systems for raised beds, container plants, and gardens than to water overhead with the hose.