Caring for Denver’s plants, lawns and trees in times of low rain and water conservation

Here in the Rocky Mountain region, water conservation is the gold standard as our climate crisis increases.

The Colorado Division of Fire Prevention and Control projects fire season will start in mid-May, with drought conditions lasting through the summer. Our low rainfall on top of another below-average snowpack winter combines with high winds to 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. Soil has a limit to water-holding capacity, so more is not always better and can be wasteful.

There are ways to care for your plants, lawns and trees while being water responsible. Low rain periods make outdoor plants and trees more prone to water stress since they gain most of their water from the soil. Knowing when and how to water is an important part of care and conservation.

General guidelines for Colorado

In Colorado, our soil is mostly clay, which absorbs water much more slowly than sandy soils. Soil compaction is a big issue in newer developments where construction compacts air pockets, giving water no place to go. Lawn aeration is good this time of the year for improving soil compaction. Aeration adds air pockets and helps water move down to the root zone.

The general solution is that a slower, more infrequent water cycle will encourage roots to grow down rather than merely horizontally. This will make plants and trees sturdier and able to tap into water table resources. Slow-drip watering is preferred for trees, and drip lines for plants.

Check out your city and neighborhood rules on watering and water conservation resources. Outdoor watering schedules exist and vary all around Colorado to limit and manage water resources because outdoor use accounts for the greatest water consumption in our area.

For Denver Water customers, beginning May 1 the water rules limit outdoor watering to no more than three days a week and only during the cooler times of day, between 6 p.m. and 10 a.m.

What about lawns?

For those with irrigation systems, sprinkler efficiency is both a part of water conservation and ensuring plants and trees get direct and deep watering.

For those with an underground system and lawns, you can conduct an audit of how effective the sprinklers are each season. Denver water offers tips online for how customers can run their own audit, at denverwater.org. The city of Fort Collins offers complimentary sprinkler system checkups, for example. Based out of Boulder, Resource Central’s Slow the Flow program offers residential and commercial sprinkler checks and support.

Automatic systems can be set to the cycle-and-soak approach, allowing for shorter, multiple cycles due to Colorado’s hard soil. Running water in shorter bursts lets the soil soak in more water, thus preventing runoff onto sidewalks and roads.

Cycle-and-soak runs for a set amount of minutes, turning that zone off while another zone runs, then cycling back through the zones. 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

Water needs for trees vary on the age and stage of the tree. For example, fruiting trees water needs increase during flowering and fruit-growing stages compared to winter needs. 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 soaker hoses or a sprinkler on a hose or in a system.

Newly planted trees are intolerant to water stress and must have more watering than older, established trees. Much of this is related to the rooting system. Longer, slower drip watering will encourage downward root growth, making the tree more resilient in future years. Tree “gator bags” are excellent for newly planted trees as they slowly drip in the root ball area.

Gardens, raised beds, and container plants

Similar to trees, newly transplanted seedlings and flowers will have greater water needs until roots are more established. Ideally, putting in some type of drip system for gardens, raised beds and container plants is more water-efficient and consistent than overhead watering from the hose.