Watering Trees in a Drought

As some of you may know, Denver’s Board of Water Commissioners recently declared a Stage 1 Drought as a result of historically low snowpack, which we rely on for our city’s water supply. Residents are being asked to reduce their water use by 20% to mitigate the current drought, and prevent our communities from experiencing even stricter water restrictions as we head into warmer months. So, what does this mean for tree lovers? We know that drought can be scary. Trees play a critical role in the health of our city, and many of us worry that our trees might not get the water they need to sustain them. A tree’s decades of growth can be lost in a single year of inadequate care. But we also see this as an opportunity to maximize our impact on the urban forest, to promote tree care and adapt our yards and neighborhoods to water-wise landscapes that will continue to provide you shade, while also harvesting available rainwater, protecting pollinators, and keeping Denver green and beautiful. Here are some things you should know:

What should you water during the drought?

We’ve been here before and we’ll be here again. Weathering Denver’s extreme temperature shifts, unpredictable snowpack, and increasingly hot weather is a challenge for us all (more lip balm anyone?). We’re all on outdoor water restrictions and have to make hard choices about where to use this limited resource. What should you water in a drought? When choosing what to water outdoors and when, we’ve got you.

Priority #1: Trees and shrubs – Trees and native and adapted shrubs provide greater benefits to Denver’s landscapes (and are, in our opinion, more beautiful!) than lawns. These woody plants are our longest living and slowest growing. Losing one now will set you back years and ultimately lead to more outdoor water use due to evaporation in hot, exposed areas. So when choosing what to water in a drought, choose to water your trees.

Priority #2: Perennials and low-water grasses – in drought years, look to our native prairie landscapes for inspiration on what grows well here in Colorado. Consider reducing lawn areas that aren’t getting used and replacing them with Coloradoscape. Denver Water has a ton of great resources on transforming your landscape, including some incentives.

Last priority: lawns – in areas that aren’t actively used for play, these areas aren’t doing anyone or anything any good. And while often presented as lower maintenance, lawns do not contribute to the health of our communities, and actually use larger quantities of water than trees or shrubs at any stage of life. They also house Japanese beetle grubs and take up acres of native grassland to grow. Let ’em brown up – they’ll come back in the monsoons just fine. Bonus: if you have a tree adjacent to your lawn, watering your tree will keep your lawn and surrounding environment cool!

Tree Planting During a Drought

Good news! There’s good reason to keep planting – our forest needs consistent care and growth – and no change to our recommendations. We worked with Denver Water to ensure that you’re good to do what’s best for the tree. Here is a link to our Tree Planting Guidelines. If you can get out there before 10am or after 6pm, that’s still best.

Tree Establishment Watering During Drought

Once planted, you need to follow Denver Water’s outdoor watering restrictions. Good news! Hand-watering and drip irrigation will be your friends:

• There are no restrictions on which days of the week you can hand-water or use drip irrigation, or how much water you can use
• You SHOULD still follow time-of-day restrictions for both hand-watering and drip irrigation: Water before 10am and after 6pm (this is also better for your tree, as less water will be lost to evaporation)
• If you need to water between 10am-6pm, you can apply for a temporary Watering Establishment Permit from Denver Water to establish your new tree
• For hand-watering, you will need to use a hose nozzle (like the one pictured) to control the flow of water

Additional Resources for Tree Care During Drought

• Colorado Department of Agriculture: Drought
• University of Florida IFAS Extension: Tree care during a drought
• Texas A&M Forest Service: Watering trees during drought
• Colorado State Forest Service: How to water your trees this winter
  • This resource also applies to other seasons of dry or cold periods