Hi Rachel,

Colorado winters can be dry enough that supplemental water for all shrubs and woody plants is recommended when weather is above 40 degrees F, and there is no snow on the ground. This is especially important for younger plants, but can be just as important for older plants when it is dry for long periods. Here is a publication that describes Fall and Winter Watering. Here is one on general watering in our climate. It's important not to overwater as well. Our clay soils do not drain very fast so you can harm a plant by overwatering it too.  Droughts You can test the soil around your plant by simply feeling it to see if it is wet, or by using a screwdriver. If you can push it in easily it probably is moist enough. These rules apply to spring as well. It's important to water in our dry climate once the temperatures start to rise and when we are not receiving enough rain or snow to keep the soil wet. Wind also can dry things out quickly, so it's important to take that into consideration and check your soil. 

Mulching around plants helps retain moisture. Two inches of mulch will help keep moisture in and also keep weeds from growing. Leave a few inches around the base of any plant free of mulch. 

I hope this helps. 

Let us know if you have any other questions.