The Great Mulching of 2004

Worm vs carabid larva - a nose-to-the-ground moment.

If any of you ever decide to turn your lot into a bug garden, or plan any major renovation of your garden, then I highly recommend that you first have a plan that maps out what the garden will look like when it is finished and the new plants have grown to their full size. We at the Home Bug Garden Wannabe were fortunate to have a friend, Adrian Thysse, with the expertise and interest in ‘naturalistic gardening’. You can learn a bit about Adrian’s naturalistic gardening and enjoy many a striking picture at Gardening Zone 3b.

The first choice we had to make was how much lawn did we want to keep? I think I’ve already expressed myself about lawnmowers, but to put a more positive spin on it, Dennis vanEngelsdorp has a great slogan “Make Meadows, Not Lawns” (hat-tip to Bug Girl). I didn’t want any lawn, but my wife wanted a bit of green near the pond-to-be. Also, on reflection, all the neighbours have lawns and offending them wasn’t on the agenda, so I decided to keep the first two metres of the front lawn intact (the city owns that land anyway). That way people walking by could have their grass fix and a chance to admire the contrast with the rest of the garden. The rest all had to go.

The mulching begins.

Adrian suggested newspaper, mulch, and patience, rather than removing the turf or glyphosphate. The technique involves laying down a layer of a half dozen sheets of newspaper directly on the lawn and covering it with about a decimetre (4”) of mulch. This blocks off all light and the lawn gradually dies and turns to compost, resulting in a nice bed to plant into. Newspaper may work okay in a dry year, but 2004 was very wet and the weeds and grass started popping through. I then switched to cardboard – that works better, but crabgrass is an amazing plant that can even puncture its way through landscape cloth (don’t use the latter if you are planting perennials into it – the roots tend to run along the underside of the cloth and will be badly damaged if you need to remove the cloth or move the plant). For the really tough spots, I ended up using 1/8 inch plywood – nothing gets through that. Another advantage of this technique is that you spend a lot of time on your hands and knees with your nose in the ground and get to see lots of neat insects.

And so it began, mulching and planting through with things we thought pollinators and birds would like. Yes, the original Home Bug Garden idea hadn’t really developed past the birds and bees stage, but it was a start.

Andrena bee departing a globeflower

Crabgrass, Dandelions, and a Dying Birch II

When last we visited the early evolutionary stage of the Home Bug Garden, I ended with a serious aesthetic problem in the front yard (a birch dying from drought and beetles) and a bit of a moral dilemma (I’m not against pesticides properly used, but poison in my own yard? and pay for it?). Moreover, the birch was surrounded by alien invasive plants – plants officially listed as ‘nuisance weeds’ in Alberta: quackgrass (aka crabgrass) Agropyron repens and dandelion, listed as Taraxicum officinale, but actually a complex of mostly asexual ‘species’. Although a weed, I’ve always found dandelions fascinating – edible leaves, flowers with which you can make wine, and a nagging question - why does an apomictic plant place such a large investment in flowers and nectar that gain it no obvious benefit at all?

‘Nuisance’ is the lowest rank under the Weed Control Act, ‘Noxious’ is worse, and ‘Restricted’ a real problem. However, it didn’t take much poking around to find that our new yard was infested with quite a few other nuisance weeds that we were supposed to ‘prevent the spread of’ (e.g. Creeping bellflower, Wild buckwheat, Common chickweed, Rough cinquefoil, Hemp nettle, Annual sow thistle, Shepherd's-purse, and probably several other weedy mustards that I was too lazy to key out) and two ‘noxious’ weeds that we were obligated to ‘control’: lots of Canada Thistle (Cirsium arvense) and one Oxeye daisy (Chrysanthemum leucanthemum). To add to the complexity of the problem, these weeds were providing the only real sources of nectar and pollen in our yard.


To top this off, I hate mowing the lawn, hate the sound of lawn mowers, and generally think weekends should be for relaxing in the garden with a couple of bottles of wine, a good book, and some good food. My wife found a non-solution to the second complaint – she bought me a push mower - but that did nothing to quiet the neighbours, and in general I would have to say that push mowing, while inducing a certain sense of moral superiority, is not conducive to relaxing weekends. Push mowing weeds interspersed with spruce cones and birch branches is especially lacking in satisfaction.

Thus came the idea of a ‘home bug garden’ – why not get rid of all these weeds and plant lots of good plants, especially ‘natives’, and make our home a nice place for people and bugs (and other animals)? Why not do nothing about the birch (only the top 2m were dead and at least that gave our garden one species of beetle), but almost completely replace the grass and weeds with a diversity of herbaceous perennials, shrubs, trees, and potager beds of vegetables, herbs, and annual flowers? I’ll deal with the extermination of the enemy weeds, the rediversification of the flora, and the exploding diversity of arthropods and lesser animals in later posts – it took a long time. The birch also took a long time, but is simpler to explain.

If you have a tree infested with a destructive beetle pest such as the bronze birch borer, you may have a moral (and possibly a lawful) obligation to your neighbours. As the new generations of beetles emerge, they won’t just eat more of your tree, but disperse to your neighbours’ yards to continue the outbreak. Chemical control of insects under bark is difficult, expensive, and limited by legislation. When thousands of trees are already dead and dying around you, and producing large crops of beetles, then you have no hope of protecting your tree. Probably the most logical and practical approach would be to drop the tree, bark it, and burn it. We didn’t adopt this simple solution, nor did most people in our neighbourhood: the dead birch are gradually being removed, but it has taken years. We, instead, tried to keep the tree healthy and limit the infestation by aggressive watering – made easier than expected by the end of the drought.


This ‘water and pray’ approach was completely ineffectual and ultimately more costly than the logical solution, but did have the advantage of keeping the birch limping along until at least last Fall (only the aspen have yet to burst bud this year, so no prediction). Birch are pretty trees, and the birds certainly like foraging in ours each spring, fall, and winter. In 2008 we installed a bird house on one of the dead boles, and a house wren (Troglodytes aedon) soon chased off the rather bird-brained house sparrows (Passer domesticus) that spent much of that Spring trying to force themselves into the too small hole. But each year the beetles spread further and further down the bole.

During a storm in the winter of 2004-5, the top 2m of one bole came crashing down. Fortunately, no person or plant was hurt, but it was obvious we had to do something, so we forked out $200 to have the beetle infested tops of the tree cut out – and baked the logs in the sun to kill the beetle larvae. The next year another few metres of tree were dead, and so on. The birch has tried to come back and sprouted from the base, but all but the last metre and a half of the bole is dead. This Spring we spent another $200 to prune it to about 4m height, just above the level of the bird house.

So did we obtain any benefits from ‘water and pray’? Well, yes, I think it has been just about worth it. Birch branches make excellent poles in the garden and segments of trunk make very attractive stands for bird-feeders and nice backdrops for informal beds. A dead tree may look unsightly, but when every other yard in the neighbourhood has a dead birch, there doesn’t seem to be much social pressure to remove it, and a dead tree is heaven to a bird or a bug. Did we save any money? Well, no – we could have had the tree removed for little more than the initial topping and the extra water we put on cost dearly. But how do you estimate the benefit of five years of migrating warblers foraging in the tree, of wrens, chickadees, and nuthatches checking out the bird box, or of strange spittlebugs drowning even stranger wasps? In the Home Bug Garden, the last trumps all.

Crabgrass, Dandelions, and a Dying Birch I

Front yards in our Edmonton neighbourhood are fairly uniform – grass maintained at various degrees of perfection, a spruce or two, and perhaps a white birch, mountain ash, or low growing conifer. Plantings of annuals and herbaceous perennials tend to be near the foundation or in a narrow bed along the front walkway, so that whatever isn’t shaded out by the spruce is covered with grass. Weekend mornings groan with the sound of lawnmowers. In July 2002, we managed to garner one such yard with a mature specimen of cutleaf weeping birch (Betula pendula) in the midst of a ratty expanse of crabgrass and dandelions and flanked by towering spruce.

Weeping Birch are beautiful trees, especially in the winter, but they need a lot of water. For the five years or so previous to our arrival, Edmonton had experienced a prolonged drought. When water-stressed, birch are susceptible to attack by the infamous bronze birch borer (Agrilus anxius). The larvae of this small (~10 mm) blackish beetle bore through the cambium of the tree and kill it from the top down. The bronze birch borer was happily munching away on North American birch when European colonists arrived, but the weeping birch was introduced from Europe and appears to be especially susceptible to its attack. The top metre or so of each stem of the multi-stemmed birch that we acquired was already dead and infested with beetles eating their way towards the ground. Thus, we were immediately confronted with a serious aesthetic problem in the front yard and a bit of a moral dilemma.

In the posts that follow, I will be meandering between describing the evolution of the Home Bug Garden and more spontaneous posts about what is happening at the moment. Every now and then I will have a rant about something I think is important - after all, that is really what blogs are about.

The Coming-Out of the Home Bug Gardener

This is the inaugural posting for the Home Bug Gardener. The theme of this blog will be how a small plot of urban land can be changed from a sterile and mindless conformity to an oasis of biological diversity. Well, perhaps not everyone’s cup of biological diversity, but the essence of biodiversity: lots of species living together.


This project started about 6 years ago in Edmonton, Alberta, Canada. Edmonton is an urban island of relative warmth (Zone 3b in a good winter – i.e. rarely going below -40C/F) in what used to be Zone 3a Aspen Parkland, a transition zone between the prairie and the boreal forest. The area in which we live used to be a slough (i.e. a wetland, not quite a lake and not quite a marsh), but it was filled in after World War II and covered with black clay and small houses for returning soldiers (our house was built in 1951). Eventually, the streets were planted with boulevard trees, primarily green ash and American elm. Weeping birch and other drought-intolerant Betula were soon adopted as specimen trees. Apple-crabs, crabapples, and a variety of mountain ash (rowan) also made their appearance. In the early 1960’s, the Girl Scouts arrived with a variety of conifers (white spruce, Colorado blue spruce, and a few black spruce) to celebrate Arbor Day. As a result, even with a southern exposure, sunlight can be limited.

That is the background. Time, energy, and enthusiasm permitting, the story will follow.


Suggested Reading:

Owen, Jennifer. 1991/2005. The Ecology of a Garden: The First Fifteen Years
Cambridge University Press
ISBN-10: 0521018412
ISBN-13: 978-0521018418

Tallamy, Douglas W. 2008/2009. Bringing Nature Home: How You Can Sustain Wildlife with Native Plants, Updated and Expanded
Timber Press
ISBN-10: 0881929921
ISBN-13: 978-0881929928

Relevant web visits:

Biodiversity in Urban Gardens in Sheffield
http://www.bugs.group.shef.ac.uk/BUGS1/bugs1-index.html