Digging shallow

This week I skimmed off some more lawn, this time to make space for new sun-loving pollinator plants. I ordered the plants last fall, including a false aster (Boltonia asteroides) and a northern blazing star (Liatris novae-angliae) for this particular spot.

Boltonia should flower profusely in August and September

    When I last visited this topic, I was despairing of being able to plant this year because of the depredations of our puppy, Lola. Fortunately, her daycare has reopened to all comers, so I’ll have some Lola-free days for gardening. That will make this project a lot easier and less aggravating.

    The planting area I’d chosen surrounds our little garden pond. The pond is an artificial creation, an 800-gallon black molded plastic tub sunk into the ground within a circle of lawn in one of the sunniest parts of the garden. When the pond was installed in 1997, the contractor edged it with bluestone. He also set randomly placed bluestone squares and rectangles into the lawn around the perimeter. 

Bluestone around the pond before sod was laid down to make the lawn in 1997

I’ve always liked the pattern he created, but now those stones are taking up space I want to use for attracting native insects.

    I used a crowbar to pry up three stones at one corner, between a spreading Japanese maple (Acer palmatum) and a dwarf Colorado blue spruce (Picea pungens ‘Globosa’). 

Then I carved away the sparse grass—mostly moss—that had grown around the stones and trundled it to the compost pile in the wheelbarrow.

Clods of grass and soil will make good compost

    The soil in this area is quite sandy. There’s a temptation to turn it and dig in soil amendments such as compost and composted cow manure to give the new plants’ roots a soft, cushy bed. I’m holding myself back, though.

    Scientific testing has proved the conventional wisdom about “improving” the soil before planting to be wrong and counter-productive. If I turn the soil, I’ll disrupt the top few inches where most of the biological activity takes place, the soil stratum called the rhizosphere. I’ll break up the architecture created by soil inhabitants such as fungi, bacteria, nematodes, earth worms, and insects. 

Electron micrograph of soil microbes-courtesy of Pacific Northwest National Laboratory

I’ll slow the work they’re doing breaking down organic material into nutrients that my plants’ roots can use. I’ll also bring weed seeds to the surface to germinate, and I’ll introduce a rush of oxygen that will burn through organic material. 

    If I needed to add amendments to this bed, I should use the no-till approach and layer them on top. Soil organisms would incorporate them in their own time. For now, though, I’m not going to try to make rich, ideal garden soil for these native plants. It’s not what they’re used to, and it’s likely to give the advantage to their competitors, such as nonnative weeds.

Why give the weeds a leg up?

    Instead, I just spread the soil that I’d separated from the clumps of grass over the 5-by-5-foot area, covered it with some landscape fabric to discourage weeds until planting time, and surrounded the newly dug area with another hopeful construction of metal posts and wire fencing. Puppy proof? I hope so.

Ready for planting