Don’t forget the trees during drought!

Denver is home to more than two million trees, and City Forester Luke Killoran is asking for everyone’s help getting them through the drought.

“It's been extremely hot and dry this summer and with our current drought, we're seeing stressed trees more than ever across Denver. That’s why we're asking people to help water their trees,” Killoran said. “We want to make sure trees are being watered in the right places and at the right time of the day.”

This message is even more important as the Denver Board of Water Commissioners voted to officially end lawn watering on Oct. 1. The lawn watering ban will remain in effect until the board determines how and when lawn watering can resume. That means sprinklers need to remain off in spring of 2027, pending an official resolution from the board. 

“We know many of our customers’ trees receive water from irrigation systems running through the summer,” said Greg Fisher, water demand and planning manager for Denver Water.

“But with the drought restrictions, our customers need to be aware of other methods of ensuring their trees receive the water they need to survive these dry and hot times, now and in the future.”

Under the updated drought resolution approved by Denver Water’s board on Aug. 26, trees, shrubs and perennials may not be watered by spray irrigation as of Oct. 1. They may continue to be watered on any day using a hand-held hose with an automatic shut-off nozzle or low-volume non-spray irrigation (such as a drip system).

So, with that in mind, we asked Killoran, whose office is responsible for managing Denver’s urban forest, for some tips on how to water your trees when irrigation systems are turned off.

Killoran says to watch trees for signs of stress, which include yellowing leaves before fall, curling leaves and premature leaf drop.

Some signs of stress may not be visible for several years, so it’s important to proactively water trees during dry weather. Killoran also says it’s critical to water trees at the drip line.

“Each tree is different, and each tree species requires a different amount of water,” Killoran said. “That means younger trees need to be watered more frequently. Larger, mature trees require more water but applied less frequently.”

When it comes to tree health, Denver Water recommends turning to experts, like Killoran.

Additional help on watering trees can be found on Denver Water's website, the Office of the City Forester's website and on the Colorado State University Extension website. 

“Trees are critical to protect during a drought because they provide so many benefits to our community,” Fisher said. “They provide shade, cooling for homes, habitat for wildlife, as well as many social and aesthetic benefits, which is why we need to help them survive.”

Denver Water reminds customers to take steps to protect their equipment from freezing temperatures, such as unhooking hoses from spigots after watering. If a leak happens because of outdoor water use after Oct. 1, Denver Water will not provide a leak adjustment on your bill.