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Get the dirt on topsoils

AS our gardens spring to life it seems that the hunt is on to find good topsoil, mulch and compost to enrich the gardens. Really rich organic topsoil is a rare commodity anywhere in the world.

AS our gardens spring to life it seems that the hunt is on to find good topsoil, mulch and compost to enrich the gardens.

Really rich organic topsoil is a rare commodity anywhere in the world. In our region we are fortunate to have a reasonably progressive system of green waste recycling and commercial scale composting that yields consumers with locally produced topsoil and mulch. There are varying opinions on what exactly constitutes good topsoil but back in the day, topsoil had weight, it was dark black or brown, crumbly, fertile looking and smelling. Our modern composting system produces more of a homogeneous and hydroponic-looking soil. However, modern composting manages and yields tonnage each year for a growing consumer interest in gardening in our region.

Harvest Power - Fraser Richmond Soil & Fibre provides the majority of the Metro Vancouver region with topsoil, bark and mulch products. Started in 1993, the company has grown to the largest recycler in Western Canada of green waste, wood waste, kitchen organics and a limited range of paper products. Partnering with Metro Vancouver, the company is helping the region meet its green waste and organic

recycling targets while reducing the region's greenhouse gas emissions associated with landfill disposal.

Harvest Power accepts large-volume shipments from industrial, commercial, institutional and residential sources that produce household food waste, paper and corrugated cardboard, a wide range of yard trimmings, green waste and clean wood from demolition. Harvest Power's sorting, processing, anaerobic digestion and composting operation is large and diverts more than 200,000 tonnes of the metro region's recyclable materials from landfills each year. The kitchen and green waste collected at the North Shore Transfer Station is shipped to Harvest Power's Richmond facility to be processed.

Without going into too much scientific detail, the selection of soil or compost type depends on the use in the garden. If you are looking for a product to dress or protect planting beds from rain and sun damage and prevent weed growth, use compost that is light and airy and primarily wood based with a high carbon to nitrogen ratio. Good examples of mulches that protect soil while preventing weed growth include hemlock-fir, or Douglas fir bark mulch.

Wood chips from arborist operations can make good mulch depending on the type of chips. Bulk leaves from most trees can be used as a mulch to suppress weed growth over the short term. Leaves can be applied unprocessed or shredded to improve their appearance. One more note on mulch: it should not be dug into the soil, leave it on the soil's surface to do its work year-round.

Organic mulches such as homemade compost, soil amender, composted bark, animal or mushroom manure will not suppress weed growth due to their fertile organic matter content. Those types of compost and manure should be used to provide a soil fertility boost and provide antibiotic protection against diseases which is ideal for veggies, roses and other specific plants.

It is important to remember that mushroom manure has a high pH and it may contain high levels of soluble salts left over from the mushroom growing process that can be damaging to plants. Therefore, mushroom manure should not be used to mulch beds or amend soil more frequently than once every five years.

As for the use of millet, coconut fibre, canola seed, pine cones, corn husks, sea weed and whatever else the so-called gurus are calling their flavour of the month, those products are simply not affordable or available in quantity commercially. So I consider all of those products to be nothing more than cult products suitable only for hippie-gurus or micro-farmers.

Topsoil should not be used to dress or mulch beds because topsoil is too heavy and it can suppress plant growth by limiting air and water exchange between the earth and the atmosphere. Topsoil also allows blown-in weed seeds to readily germinate which defeats the purpose of mulching.

Topsoil comes in two primary mixes: garden blend for use in building new garden beds or turf mix, which is used for topdressing or building new lawns.

On the North Shore - aside from the "buy by the bag" suppliers like garden centres and home stores - there are two main companies that sell topsoil and mulch products direct to consumers. They are TL Roberge Trucking (robergetrucking. com) and Dalton Trucking Ltd. (daltontrucking.ca). Both companies offer a range of topsoil, mulch and compost products for garden use that you can pick up or have delivered.

One final word on topsoil. If you decide that you will try to find topsoil "off the market" be aware, you risk importing noxious weeds such as horsetail, morning glory, dandelion, buttercup and other pernicious weeds into your garden. [email protected]