All the advice about winter watering can be so confusing. Okay, it makes sense that in order to help landscape plants survive the dry winter, you need to water them. But how often? Once per month? Once every two weeks? Once a week? And didn’t that recent big snow help?
In order to understand how often to winter water, we need to understand three things about roots. First, roots are critical to plant growth. I remember Curt Swift, a Colorado horticulturist, say, “Healthy roots mean healthy plants.” If you want to set your plants up for success this summer, make sure they grow healthy roots.
Second, many landscape plants grow a major flush of roots in the spring. This is especially true for plants that grow best in the cooler seasons of spring and fall. The larger roots are permanent, but the smaller roots grow each season and eventually die later on. Roots start to grow when the soil temperature is 40 degrees F. That means many are starting to grow now. You may have noticed your lawn starting to look a little greener. They will continue to do so into April and May. The smaller roots take up water and nutrients, so they are very important.
Third, in order for plants to grow a healthy flush of fine roots, the soil must be moist. If it’s bone dry, the new roots will not form. A healthy flush or roots makes the plants more tolerant to drought. This will be very important this summer as many communities will be in mandatory watering restrictions.
In order to ensure the soil is moist, we need to water it. In particular, we want to make sure the root zone is moist. Even though roots are different depths, most fine roots will be in the top 12 inches of soil.
How do we know if the root zone is already moist or not? One of the best ways is to use a soil probe. This is a handy device that you use to remove soil cores so you can see how deep the moisture is in your yard. By sampling different places in your yard you can target your winter watering to the places that need it. I’ve found that there are so many differences in my own yard, let alone different sites around the Front Range.
I’m going to sample my yard today. I’ll let you know what I find!