Short sightedness of current water restrictions, part 2

In my last post, I described how water restrictions mandating hand watering only can lead to fewer trees and plants, which in turn will cause our temperatures to increase.

At stage 4 of the GVRD water restrictions we will not be able to water any plants using treated drinking water, including vegetable gardens.  http://vancouver.ca/files/cov/water-use-plan.pdf

Again, the short sightedness of this plan is puzzling.  If we must allow our vegetable gardens to wither, the consequence will be buying more imported food.  Imported food requires more expended resources in our environment:  commercial levels of watering;  transportation costs;  possible loss of nutrient value in the food through storage, etc.

Here is a link to an excellent video on how bringing trees to the desert, actually moderates the climate:  https://www.youtube.com/watch?v=K1rKDXuZ8C0.  In the GVRD, we seem to be aiming to do the reverse procedure.

Short sightedness of current water restriction stages, part 1

Here in the Greater Vancouver Regional District (GVRD) we have 4 stages of water restrictions.  Beyond stage 2, we must water all gardens by hand, unless the garden is a commercial flower bed apparently.

Watering by hand is laborious and usually less effective than using a timed sprinkler.  Most of us get tired and bored of standing around with a hose.  The result is shallow watering which leads to shallow roots as the plant's roots have to come towards the surface to seek water.

The missing perspective in the water restrictions is that we need trees and plants to provide shade and to transpire into our environment.  If our gardens are shadier, they need less water.  If we have more vegetation, we will need to water less.

Think about walking down a sidewalk on a hot afternoon, not shaded by large street trees.  Then think about walking down a sidewalk on the same afternoon, under the canopy of large chestnuts or maples.  The difference in temperature is noticeable.  The following article breaks down the effect of vegetation more scientifically:  http://www.forestry.gov.uk/pdf/FCRN012.pdf/$FILE/FCRN012.pdf.

If we stop watering our gardens, we will lose a lot of vegetation, and the temperature will increase.

How to find resilient plants for our changing climate

Here in Vancouver, we are in our second rainless summer month.  This used to seem unusual, except last year we also had a record lack of rain.  Combined with almost no snow over the winter, and we have Stage 2 water restrictions already at the beginning of July.  This means we have to rethink our gardens.

Drought tolerant boulevard plants

Now is the time to look around your neighbourhood for plants thriving without irrigation.  For instance, we installed the boulevard plants shown in the photo about 5 years ago.  This group of plants never gets watered, and is in a south facing position, on a corner, with no shade.  These same plants tolerate our winter deluges of rain.

The plants pictured are Lavandula augustifolia (Lavender), Caryopteris, Physocarpus opulifolius 'Diabolo' (Ninebark--a native plant), and Podocarpus alpine 'Red Tip' (Tasmanian Podocarp).  The order is Lavandula, Caryopteris, Physocarpus, Caryopteris, Podocarpus, Lavandula.

The seriousness of this season's drought

Here in Vancouver, and in many areas of the world, we are experiencing a drought.  Our drinking water reservoirs are dependent on snow melt from the surrounding mountains, and last winter's snow fall was far below average.  This will probably mean stage two or higher irrigation restrictions for gardens this summer in Vancouver.

Last year we also experienced a summer drought in Vancouver.

What does this mean for gardens?  Often the effects of negative situations take a year to show up in large plants, like trees.  The trees appear to be only mildly affected by circumstances initially, but if the detrimental situations persist, trees will be adversely affected.  For instance, I noticed the Chestnut trees lining Renfrew at the PNE grounds are already covered in dead leaves.  Chestnuts suffer as street trees in normal summers, but are not usually covered in dead leaves in June.

Large trees are able to obtain water from the water table with their roots, but when the water table lowers due to drought, the trees lose this resource.

Ironically, large trees and all vegetation reduce temperatures and create moisture in the air through transpiration.  Keeping our plants alive is the best way to reduce drought conditions.

Now is the time to look around your garden and your neighbourhood gardens, to see which plants are performing during this drought.  Pay attention to gardens that are not slavishly irrigated, but ones that are irrigated responsibly, i.e.: if the lawn is lush and dripping wet, this is probably not the home of a responsible irrigator.  What plants still look good?  What plants are looking crispy?  Note if the plants are in the shade or full sun.