Living in the Okanagan, water is always on our minds. It is sometimes in short supply for people and sometimes in short supply for plants.
As gardeners, we need to understand the water relations that plants experience and also realize that the volume of water we use in our landscapes far outweighs the water we use for personal consumption.
One plan may be to reduce watering in our gardens when it’s not needed. So when is water not needed? Well, when plants are growing they use a lot of water, when plants are warm they use a lot of water, when deciduous plants have leaves they use a lot of water. When it is warm and windy plants use water.
So as the seasons cool down and plants go dormant they have less need for water.
And anyone who has attended my talks on the importance of oxygen to the root systems of plants will know that plants do not like being waterlogged.
So what are the water requirements of plants during the dormant period?
There are a few things to consider. Plants that hold their foliage during the winter (evergreens) have their leaves exposed to the desiccating winds. These plants, like any plants, do not like being water logging but during the winter, when temperatures come above the freezing point, they need to have some liquid water to take up.
When there is snow on the ground the thawing allows water to enter the soil providing the surface is not frozen solid.
Plants that live under the eaves of a house are in a tough spot and will often perish during the winter due to complete desiccation. So, when the temperatures are above freezing and the soil thaws it is important to get water to these plants, especially the evergreens.
Now other deciduous plants only need a moist condition that is not water logged to be healthy over winter.
Some so-called gardening experts may convince you to drown the plants in the fall when they really only need a good soak in about mid-October then left alone until spring (except the under eves plants). The best case scenario may look like this: We start reducing the water in our irrigation systems in about mid-September not by duration but by frequency. This means keep a good soak going when you water but don’t water as often. Depending on the weather, once or twice per week should suffice.
Once in October we reduce to one day per week for sure or even less if the fall rains are generous. By mid-October hopefully the ground is breathing and not overly saturated or we may have to withhold all water from here on out, but normally in this valley things are drying out.
Regardless of irrigation system function (unless your property is very large) using a trickling hose around your evergreens first then other trees and shrubs to give a final soak before winter would be suggested.
By November most plants are quite dormant and water need has dropped off. Now through the winter months we need only observe.
When we do get snow, moving some onto evergreens first especially any under eves is a priority.
Other plants will usually survive considerable drought due to the lack of leaves.
We have often mentioned to our listeners on The Garden Show to drain your hoses and store one in a garage for winter use if needed. Just remember that plants sitting in water over winter have as much or more of a chance of dying from drowning as dry plants have from dying of drought.