Winter Watering & Mulching

Posted by: Susan Carter, Tri River Area Extension

Ornamental Pear, newly planted

Fall has rapidly come and gone.  Luckily Western Colorado got some rain before the cold set in allowing plants to go into winter hydrated.  I have noticed some trees around the Grand Valley have really hung onto their leaves that typically don’t this late in the season.  Now some trees like oaks will hold onto their leaves for most of the winter, but I have gotten calls about Cottonwoods still with leaves and have notices a lot of Ornamental Pears and others still green or with some fall color.  My theory is the 80 degree weather we had in October didn’t allow the plants to slow down as they should have.  Slowing down on irrigation in late summer and and fall helps them get ready for winter as well.  We will see in spring, how these trees fair. 

Fastigate Oak, Mesa County Fairgrounds

So the question is, what can I do till then?  Well, keep an eye on the moisture is the best thing to do.  Many plants, especially newly planted and evergreens, struggle with our cold dry winters.  At higher elevations, where snow is deep, it insulates the ground and holds in moisture as well as the temperature.  At lower elevations, the soil conditions can be more extreme freezing, thawing, drying out…  When we only receive an inch or two of snow, that snow just evaporates into our dry air leaving little to none for the plants.  So, about once a month on a warm day when the soil will take moisture, drag out the bucket or hook up a house to the building and water these plants.  Now remember trees do not like their trunks wet and if you think about a tree in the woods, up close to the trunk is not where the rain falls. 

Pine and Arizona Cypress

So make sure you are getting water all the way around the drip edge  (the tips of the branches) of the tree and out and soak early in the day so it can absorb.  See our factsheet on winter watering: http://extension.colostate.edu/topic-areas/yard-garden/fall-and-winter-watering-7-211/

and the Plant Talk: http://www.ext.colostate.edu/ptlk/1706.html and call your local CSU Extension office if you have other plant questions.  

The other thing you can do to hold in moisture and to help with freeze damage is to add some mulch.  Add several inches of wood mulch or clean leaf litter.  On most plants you want to keep the mulch away from the trunk.  http://www.ext.colostate.edu/mg/gardennotes/245.html  

The one exception for breaking the mulch rules, is here at lower elevations after we have a freeze or two, pile the mulch at the crown of your roses.  http://www.colostate.edu/Dept/CoopExt/4dmg/Flowers/Perenls/mulch2.htm  This protects the graph union from freezing so hard so you "Don't pull a Huey".  Huey is a common red flowered root stock of roses, so know you know where that saying came from and know why your yellow rose turned red, its the rootstock.  Remove this volcano of mulch from  around the roses in mid April when it starts to warm up.  To all of you humans, hope you keep warm and hydrated this winter as well.  

Happy Holidays.