Yesterday was a glorious snow day. There was light fluffy snow falling steadily all day. It gathered about three inches on the car, but this morning, winds have reduced what’s on the ground to a rather negligible half inch. That great day of snow is going to amount to almost no actual water getting into the ground. In dry climates like Colorado, the snow evaporates under relentless winds or high sun and after a day of warm sun, it won’t be muddy or wet in the garden…except in little north side niches.
The taunting appearance of moisture is one of the reasons I made my own winter watering decision matrix…so I would have a methodical approach of deciding when to water in winter and not just let visual clues like ”it snowed all day” decide whether watering is necessary.
So here’s my Decision Matrix for Wintering Watering:
Has it been dry without significant precipitation or snow cover for the last two weeks and/or have the temperatures been warmer than usual?
If yes, the next step is to walk outside and ask,
“Is the ground frozen?”
If the soil is frozen, winter watering doesn’t help anything. Any water would just roll off the soil and not do the plants any good. Go back inside.
I usually wait until a couple of days of warmer or sunnier mid-day temps and repeat the “Is the ground frozen?” question in the afternoon.
When the soil is thawed, then the next question is,
Did I plant new plants in 2012? If the answer is yes….then you need to winter water those plants once a month during dry times. This is true for new trees, bushes and perennials. You need a good slow soak right at the root ball.
Now move to other parts of the garden with older plants and ask, “When I put my finger in the soil, is it moist one inch down? You’re checking the soil here….not just the mulch on top of the soil. If it’s still moist, then go back inside and leave the water in the aquifers.
If the soil is dry an inch down, water now to save the lives of your plants and especially your trees which have suffered greatly with drought in most of the country over the last year.
Water slowly so it can seep into the soil. A good rule of thumb is 10 gallons of water per inch of stem caliper. If you have one of those root watering spikes….insert it shallowly…less then six inches….most roots are rather shallow and you don’t want to water under the roots.
Here are resources: a winter watering fact sheet, and the US Drought Index. Most of the country is under greater drought now than it was a year ago. In Colorado after the drought in 2002, we lost many of our trees the following years….because the impact of one year of drought stresses trees and plants for years. So this is the time to save your landscape. Don’t water on top of snow or frozen soil….but keep your decision matrix in mind as we finish out this winter.