Published in the Toronto Star July 9, 2016
There is something primal about water. When the animals on the Serengeti Plain have finished a busy day of chasing each other or being chased, they generally meet at the local watering hole for refreshment. There you will often find antelope and lion sipping fresh water from the same pond. When the heat hits home we head to the cottage or the water park. It both cases we are responding to something that is hard wired into our DNA: water is life.
We are equally driven to apply water to our garden this time of year. Everybody knows that plants need water, right? Well, yes but not too much. Allow me to illuminate you – and in so doing, offer some advice that will save you time and effort.
- Plants NEED to dry out. The hostas that are flowering to beat the band 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 of the perennials and shrubs in your garden. I look to my hydrangeas for a signal that the ground is so dry that the garden would benefit from a soak. And therein lies another key to watering success! After waiting for the appropriate time to add water, make sure that you water deeply and apply it 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 that are allowed to dry between watering dive deep into the soil with their roots seeking moisture.
- Soaker hose. When it is time to add water I recommend that you apply it using a soaker hose as it is the most efficient method of watering that I know of. Basically, a soaker hose ‘bleeds’ water out of its pores and slowly seeps water into the soil. It works best when it is buried under about 6 cm 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 is wet down to your second knuckle, you are done. There are two types of soaker hose: 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.
- 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.
- Plant evergreens. There is 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 like mugho pine, taxus (yews), boxwood, junipers and cedars you minimize the amount of water needed to help them thrive after they have become established.
- Coir/peat. Coir is a by-product of the coconut. It is the fibrous lining of the thick shell that we mostly ignore and throw away. This fiber 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.
- 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 is needed most (very little is wasted). Some areas of your garden require your personal attention, like the ferns that I have hanging from my front porch: hand watering just makes sense. Of course, that rain barrel water is warm this time of year and most of your plants really appreciate that. Rain water becomes charged with oxygen as it falls from the sky: tap water contains much less oxygen, which is something that all plants thrive on.
Finally, there is the ‘miracle of mulch’, which I have mentioned before in this column. But it is a tip worth repeating: when you spread 5 to 6 cm of finely ground up pine and cedar mulch over your garden soil around perennials, roses and other permanent plants, you insulate the soil from the drying effects of the sun. The result can be a dramatic 70% reduction in the amount of water needed and better performing plants, which are not stressed out between applications of water.
If I sound like a big fan of mulch it is because I am. I use about 40 cubic yards of it every season. YES! Hammock time!!