18 Oct

Watering tips that won't leave your plants high and dry — or drowned

The type of hose, plants and other gardening materials all make a difference in keeping a garden properly hydrated with little time and effort.

There's something primal about water. When the animals on the Serengeti plain have finished a day of chasing each other, they generally meet at the local watering hole for refreshment.

Here in Ontario, we head to the cottage or the water park when the heat hits home. In both cases we are responding to something hardwired into our DNA: water is life.

We are equally driven to water our gardens. Plants need water — right? —but not too much. Here's advice about watering plants that will also save you time and effort:

1. Plants NEED to dry out. The hostas that are flowering in your backyard right now are masters at sequestering water in their thick, fleshy roots. It takes a lot of dryness for them to droop. The same can be said for many shrubs and perennials. I look to my hydrangeas for a sign the ground is so dry that the garden would benefit from a soak. Therein lies another key to watering success! After waiting for the appropriate time to add water, make sure you water deeply and late in the day to avoid excess evaporation.

Plants are conditioned to need water by the frequency with which we apply it. Frequent watering produces shallow, lazy roots that hang around the surface of the soil, waiting for the next drink. The roots of plants allowed to dry between watering dive deep into the soil, seeking moisture.

2. Soaker hose. When it's time to add water I recommend you apply it using a soaker hose. It's the most efficient method of watering I know of. Basically, a soaker hose "bleeds" water out of its pores and the water seeps into the soil. The hose works best when it's buried under about six centimetres of finely ground-up cedar or pine-bark mulch. To know when you have applied enough water, just push your finger into the soil. If it's wet down to your second knuckle, you are done.

When it comes to soaker hoses, there are two types: one made from recycled tires that works very well but will burst under high hose pressure, and another made of synthetic material, which is stronger.

3. Plant close. When you "jam" your planting you block out much of the drying effects of sunshine, allowing for longer periods of time between watering. It sounds almost too simple to make sense, but it works. You will get a bigger show faster, too. Though you need to consider the extra cost of plants.

4. Plant evergreens. There's a reason why Christmas trees grow in open, sandy soil: they like to be dry and thrive in well-drained soil. Ditto your garden: when you plant evergreens such as taxus (yews), boxwood, junipers and cedars, you minimize the amount of water needed to help them thrive after they have become established.

5. Coir/peat. Coir is a byproduct of the coconut. It's the fibrous lining of the thick shell that we mostly ignore and throw away. This fibre is much more absorbent than peat and lasts up to three times longer. Both are inert and add no nutritive value to the soil. Peat costs less, is produced in Canada and is relatively inexpensive. Your garden: your choice.

6. Rain barrels and watering cans. The old-fashioned method of applying water has a couple of things to commend it: watering by hand, from a rain barrel, targets water right where it's needed most (very little is wasted). Some areas of your garden require your personal attention, like the ferns I have hanging from my front porch: hand watering just makes sense.

Rain-barrel water is warm this time of year and most of your plants appreciate that. Rain water becomes charged with oxygen as it falls from the sky. Tap water contains much less oxygen, which is something all plants thrive on.

Finally, there's the "miracle of mulch," which I have mentioned before in this column. But it's a tip worth repeating: when you spread five to six centimetres of finely ground-up pine and cedar mulch over your garden soil around roses, perennials and other permanent plants, you insulate the soil from the drying effects of the sun. The result can be a 70 per cent reduction in the amount of water needed and better performing plants, which are not stressed out between applications of water.