Roots, roots, roots-it’s all about the roots! These mostly underground plant structures are responsible for the majority of our plants’ health. The work they do and how well they do it can even dictate a plant’s lifespan. The gnarly, stringy, invariably dirty, and often hairy bits range in size from enormously thick tree roots to the most miniscule root hairs at the very tips.

It is in the roots that energy is stored in the form of carbohydrates and also here that nutrients are taken up from the soil. In fact, it’s those teensy, tiny root hairs who do the heavy lifting of bringing in soil nutrition and mycorrhizal interaction (working with funguses to gain more nutrients). Nutrients are used by the plant but also stored in the roots as a guard against tough times and winter.

Then there’s water. While water itself is essential for plant growth, it is also through water that the nutrient ions are absorbed by the plant’s roots. Finally, in addition to all of these other important jobs, roots are the anchors for our plants, keeping them upright and stable and helping them to withstand wind and other physical stresses.

Okay, I could go on and on about the magic of roots, but I think we all get it now, roots are extremely important. It is for this reason that winter watering is downright critical!

No matter if you’ve lived on the Front Range your whole life like me, or are relatively new here, it doesn’t take long to figure out that Colorado offers up a host of difficult conditions in the wintertime, especially for plants. Dry air, low precipitation, fluctuating soil temperatures, and little soil moisture throughout much of our fall and winter seasons means that plants are particularly vulnerable to drying out. It’s all too easy to lose what moisture they have through transpiration especially during our not uncommon windy and sunny days. Yes, deciduous leaves are gone but transpiration is still occurring through the bark, and evergreens who still have their leaves, are vulnerable to losing even more moisture. When you add in frozen soil that locks up what remaining moisture is left, there is a high likelihood that our plants will not receive the water they need.

When conditions get too dry, the plants have to cut back on their use of water and their roots begin to die back. That dieback comes at a high price. As you’ve just read, roots provide a lot of important functions and their loss can impact your plant for the next season, next year, or even for the rest of its life.

You see, at first, we don’t notice that the lack of watering has had any effect at all. This is because of the plant’s stored energy. It taps into the carbohydrates and nutrients that it has set aside in order to complete its spring flush with nary a sign that anything could be amiss. It’s only later in the season, and sometimes not until the next year, that signs of that drought stress begin to become visible. The root damage from winter will often manifest in reduced vigor, increased susceptibility to insects and pathogens, and physical changes like smaller leaves and flowers, dead branches, and less new growth. These setbacks can mean you and your plants will be dealing with issues for years to come and possibly even see the lifespan of the plant significantly shortened.

This is where wintering watering comes into play. Trees, shrubs, perennials, and lawns will all need supplemental water if they are not receiving enough from mother nature. Newly established lawns and trees/shrubs/perennials planted in the last year are especially vulnerable. Mature plants are more resilient but absolutely still need water and will pay you back for it with extra vigor come spring and summer. Don’t we all want nice looking plants? Okay, get out the hose and sprinkler and here we go:

Guidelines to help get your head in the game:

• Water only if it hasn’t rained/snowed in the last 3-4 weeks and there is no snow on the ground.
• Wait until temperatures are above 40 degrees F.
• Apply water at mid-day so it will have time to soak in before freezing at night.
• Trees obtain water best when the water has soaked into the soil to a depth of 12 inches.
• Apply water to many locations within the dripline (area that reaches as far out as the furthest branches around the entire tree, imagine a wet, leafy tree dripping).
• Application rate for trees: 10 gallons of water for every diameter inch of the tree’s trunk. So, a tiny 2-inch diameter tree would need 20 gallons of water per watering.
• Shrubs:
  • For shrubs 3 feet tall or shorter: newly planted: 5 gallons twice per month, established ones: 5 gallons once per month.
  • For established shrubs more than 6 feet tall: 18 gallons per month.
• Perennials: just do a ‘normal’ watering. Don’t try to soak them too much as you don’t need to create conditions for root rot.
• Lawns: water normally as best you can. This is especially true for areas that have a strong south or west exposure.
• Remember that any plants/trees that are located in areas that get a lot of wind, are planted higher like in a berm, are situated close to walls or other heat-reflecting structures, or get a lot of south/west sun exposure, will require more watering.

This has been my public service announcement on behalf of plant life everywhere-don’t forget to water in the winter. I know it is a bit more work and money on the front end but having a mature and beautiful landscape that is healthy and doesn’t require constant replacements and heartache is definitely worth it in the long run. Keep those roots happy, my friends!