Dead green ash trees (July 2013)

All through our (usually) dry winters, we’ve been beating the drum to get people to winter water their turf AND their trees. With our ongoing drought and irrigation restrictions, we find ourselves in the surprising position of having to remind people to “summer water” their trees.

Most of the trees in our area have been introduced and can have a tough time thriving even when we are not in drought. After several consecutive years of drought, super late hard freezes this year, and watering restrictions, our trees are having a tougher time than ever surviving. Many trees that have been on the edge of survival for the past few years have finally died this year and others are very close (like those trees in the downtown medians with about a quarter of their normal leaf cover). (more…)

sprinklertimer.jpgAutomatic sprinkler systems can make irrigating our landscapes (especially lawns) much easier, and they can also help us water more intelligently. In our area, we are usually encouraged to water lawns early in the morning or late at night. This is simple with a sprinkler system timer that can be set for any time of the day or night. Consistent watering is also important, especially during drought (a.k.a. now), and the timer easily takes of care of making sure your lawn is watered when you are away on vacation. In a previous post, I described rain sensors that can be added to your system so that it won’t run during or immediately after a storm. You can even find sprinkler controllers that incorporate weather sensors that turn the system off during high winds and incorporate local ET data to set sprinkler zone times. (more…)


Drought-stressed American Elm

I fear I’ve started to sound like a broken record these past few winters (“We’re having another DRY winter,” etc, etc). Yes, we’re having another very very dry winter, AND we’re having exceptionally warm temperatures. Usually I wait until early in January to send out a winter watering reminder, but this year, it feels really important to get the reminder out now. (I promise more on our current water situation will be coming soon.)

Local tree services are reporting big increases in calls about failing established trees and shrubs, including lilacs! Even I’ve never really worried too much about winter watering my established lilacs. I’m sure some of the problem stems from not-particularly-xeric plants that were not adequately watered the past few winters or during the summers (which have also been dry). But even drought-tolerant species need a minimal level moisture, and recently, they’ve been rather challenged to get it! So this is a bit of a wake-up call to not just focus on our new trees and shrubs when winter watering during these dry years. (Take a look at some of the downtown medians if you want to see what happens when we neglect big, established trees during drought.)

Q: I have seen people watering their lawns even though it is November! Aren’t we supposed to stop watering once temperatures go below freezing?

A: When it comes to gardening Colorado has a lot of challenges – especially in winter. Dry air, low precipitation, desiccating winds, little soil moisture, and fluctuating temperatures are the norm. Our driest months occur during winter, and many woody plants have shallow root systems which cannot tap into the underground water supply.

Landscaping is a major investment and in order to protect that investment, watering in winter is a must. Trees, shrubs, and herbaceous perennials can be damaged if they do not receive supplemental water. Newly established lawns are especially susceptible. Plants that receive reflected heat from buildings, walls and fences are also vulnerable to damage. And, windy sites require additional watering. (more…)

Q: What can I be doing in my yard and garden in early spring?

A: Here are a few tips to get your yard ready for the growing season.

Rake up last fall’s leaves, pine needles, thatch and other debris. Make sure the grass is getting adequate moisture to avoid grass mite damage and other dry turf problems.


photo by Don Bunce, Colorado Master Gardener

Aeration plugs

Aeration is the best way to help your lawn thrive. It will reduce thatch and soil compaction, improve water and air absorption, encourage healthy root growth and control weeds. Remember to flag sprinkler heads before aeration. Plugs should be evenly spaced and two to three inches long, so watering well beforehand is a must. Aeration provides a great surface for fertilizing or over-seeding.


Fertilizer should be applied when grass is actively growing. Fertilize cool grasses such as Kentucky bluegrass, fescues and ryegrass in the spring. Wait to fertilize warm weather grasses such as buffalo grass, blue grama, and bermudagrass in midsummer. Colorado lawns prefer a fertilizer that is primarily nitrogen and includes some iron. Mulching mowers leave the grass on the turf and essentially provide all the needed nitrogen. (more…)