EVEN with the kids going back to school, summer is not over yet; and so don't give up on the garden, especially when it comes to watering.
Our coastal weather is traditionally warm and can even be hot in September and plants growing in urban settings still need to be watered to keep them healthy until the cooler weather of October arrives.
For plants that were newly planted this summer it is particularly important to keep up with establishment watering once every six to seven days to allow new plants to develop deep root systems before winter arrives.
It is also important to remember that our regional watering restrictions only apply to lawns, not to ornamental plants, veggies and new plantings.
Whether you water by hand, sprinkler, soaker hose or in-ground irrigation system, the most important job to do after watering is to determine if the watering duration and volume was sufficient to adequately water the garden.
It is all too common an occurrence for people to turn on the water and let it run and then turn it off without checking to see how deep the water has penetrated into the soil.
To check how effective any watering system is, dig a straight-sided hole about 30 centimetres (one foot) wide and anywhere from 30 cm to 60 cm deep depending on the rooting depth of the plants being watered.
Dig these wateringcheck test holes in four or five locations amongst the watered zone. Cut cleanly along the back side of the hole and look carefully to see how deep the soil has been moistened. You may need to use your hands to touch the soil to check for moisture if you cannot see the moisture differences in soil. At minimum, watering should penetrate to the bottom of the rooting depth of the crop.
If water does not penetrate to the bottom of rooting depth, plants will begin to grow roots upward towards the water which results in shallow rooted plants. Shallow rooted plants are prone to browning out, wilting and dying during times of drought.
Deep rooted plants are better able to withstand drought because they can access deep soil water reserves. Plants with deep root systems are also able to store water in the deeper parts of their root systems.
One of the common misconceptions about inground irrigation systems is the assumption that regular programming and schedules will adequately water the garden.
Few if any irrigation technicians check the existing soil structure in the garden to calibrate irrigation systems. And most irrigation calibrations are solely dependent on schedules, programming and making sure that water is not pooling or running off the soil surface.
Watering plants effectively depends on four factors: the volume (amount) of water applied, the duration (length of time) the water is applied, the type of crop (plant species) and the type of soil (soil textural classification).
Scheduling, programming, controllers and sensors are simply tools and frankly, irrigation systems lack all knowledge of soils or crop watering requirements, which is why it's important for a person to understand how to water, not a machine.
For the past 20 years, the irrigation industry has slowly moved to using micro-heads, drip irrigation and low-flow irrigation systems in an effort to conserve and use water more efficiently.
Water conservation is a good thing especially in light of the provincial government's recent revision of British Columbia's Water Management Act that will require everyone to pay more fairly for water use but one of the problems with low-flow systems, drip irrigation and soaker hoses is that those systems must remain on longer to supply sufficient water at depth. And drip irrigation only waters a small area of the soil compared to overhead watering systems that water wider areas of the garden.
Ultimately, it does not matter what watering system you use in the garden but it is important to understand how deep the water has penetrated into the soil according to the water needs of the plants being watered.
I cannot give detailed watering recommendations without knowing the plant species, soil type and watering system and neither can anyone else.
I can say, however, that deeper watering is better than shallow watering.
And watering plants based on their needs and drought tolerance is better than watering on a schedule.
I can also say that overwatering produces waterdependant plants that adapt to being continually watered, which lessen their drought and frost tolerance.
Learning the intricacies of your own watering system, understanding each plants' drought tolerance and understanding how well the soil holds water, combined with a monitoring regime of digging a few test holes after you water to see how deep the watering has penetrated, will provide the most accurate watering results.
Todd Major is a journeyman horticulturist and chief horticultural instructor at the University of British Columbia Botanical Garden. For advice contact him at stmajor@shaw. ca.