Photo: Kirsty Hall/Flickr

Five Commandments of Composting

1. Have enough mass: compost bins come in all shapes and sizes, but to produce enough heat to break down the kitchen scraps and yard waste that magically turn into compost, the dimensions of your bins need to be at least three by three by three feet. Any smaller, and there aren’t enough plant sugars for bacteria feed on, and the more feeding that goes on, the more heat that’s generated. Lowenfels also recommends using a bottomless bin that sits right on the ground, rather than the tumbler types, for example, because they will attract indigenous micro-organisms to the compost pile.

1. Get the mix right: A balanced compost pile has a carbon to nitrogen ratio of 30:1. For all you soil scientists, an Internet search will reveal a lab full of online compost calculators that will tell you exactly how to achieve this ratio (for example, see www.agric.gov.ab.ca/app19/calc/manure/manure.jsp). If you’re really into this, you can get caught up in the formulae till the cows come home, but for we ordinary folk, try not to worry too much about it too much. As long as you add more “greens”, such as kitchen scraps, than “browns”, for example, dried leaves and grass clippings, “compost happens”, says Lowenfels. I can certainly attest to that. For years, I’ve been making compost in my backyard without the use of a slide rule, just by tossing in whatever’s in the kitchen compost can and debris from the garden.

1. Keep it moist: Without water, there is no life. It’s the activity of those trillions of microbes that breaks down the organic matter in your bin into compost. Dead microbes do not a compost pile make, so make sure your bin doesn’t dry out.

1. Let there be air: Just as all organisms need water, so they need air to breathe. An airy compost pile decomposes quickly. A pile without air becomes anaerobic, a dead zone that is stagnant – and stinky! So, turn your pile frequently. (Lowenfels recommends the following aerating regimen: turn the pile on days 2, 5, 7 and 11, repeating until the compost is ready.)

1. Heat it up: To kill most weed seeds, the internal temperature of a well-maintained compost pile should hover around 58°C. Surprisingly enough, that’s easy to achieve by following the four previous commandments – and it has nothing to do with whether your bin is in sun or not. A compost bin sitting in the shade will heat up just as much as one in the sun – as long as the bin is large enough, you’ve added the right mix of organic materials, and there’s enough moisture and air.

Finish your spring spruce-up by edging flowerbeds. The easiest way is to dig a shallow trench between lawn and border using an edger (a half-moon shaped tool available at hardware stores). It may take time, but the payoff is a garden with a professional edge!

Raking the lawn is not only a pleasant spring pastime, but it helps remove thatch buildup, which can weaken the roots of turf grass. Rake off the winter mulch from flowerbeds too, so they warm up faster. Reserve the mulch, mix it with compost and reapply as a top dressing in a few weeks.

Skip this task if you were good and cleaned, sharpened and oiled your shovels, secateurs and spades last fall. For those of us who put it off till spring, unearth abandoned gardening tools and forsaken containers, and clean them up so they’re ready for another season.

Before they get out of hand, control annual weeds that germinate in the spring, such as crabgrass, purslane and lamb’s quarters, and perennial weeds that overwintered, including chickweed and wild mustard. Hand pulling is most satisfying, but there are organic herbicides and all manner of specialty tools available, like this dandelion puller from Fiskars, that do the trick too.

Although compost makes an ideal spring tonic for plants, to keep them blooming their best, flowering shrubs, trees and vines benefit by a dose of fertilizer too. Apply slow-release fertilizer granules formulated for flowering shrubs and vines such as roses, clematis and rhododendrons – then stand back and watch them bloom!

Take only one piece of advice and yours will be the most robust garden in the neighbourhood: Feed the soil to feed your plants. One of the best ways to feed the soil of perennial garden beds is to top-dress them with a layer of compost every spring. Compost adds nutrients to the soil, and improves its tilth (the horticulturally correct term for “crumbly”) – as well as plant health.

Hardy perennials can weather the pre-May 24 weather, so beat the rush to the nursery and select some of the season’s choicest plants as soon as they arrive. Once the ground has thawed and dried out, it’s a good time to plant shrubs and trees too, especially magnolias, birch, oak, yews, rhododendrons and azaleas.

Think back to last season. Did the flowers of your phlox seem a bit smaller than previous seasons? Did the middle of your clump of dianthus brown out? Were the stems of your yarrow so tightly packed that they seemed to be choking the life out of the plant? These are signs of decline that dividing can conquer. Tease apart baby crowns of plants such as coral bells and hardy geraniums, and cut large clumps of daylilies and hostas into smaller pieces. Discard the tough, mature sections, and replant the newer growth that generally appears at the outer edges.

Rule one of pruning: if a shrub blooms in spring or early summer, wait to prune until after it blooms. Otherwise, you’ll be nipping the current season’s flowers in the bud! Now is the time to prune late-flowering shrubs such as rose of Sharon, hydrangea (the mop-headed Annabelles can be cut right down to the ground), butterfly bush and roses. Cutting back dogwoods ensures a fresh flush of flaming red or orange stems which will look fabulous against the snows of next winter. But, before applying secateurs to limbs, though, consult a pruning book with good illustrations that clearly show you how.

One of my favourites is Lee Reich’s pruning primer.