Preventing Weeds

(Question)

Hi Gardening Friends! I live in East York and have a backyard that slopes away from my house. I think the soil is quite poor; it’s very compacted, hard, I don’t think it drains well and it seems to have a lot of clay. There’s no grass (I intend to plant a groundcover next year) and it’s shady. Right now the only things that will grow are dandelions! I’ve just spent the entire day digging them out and want to prevent them and other weeds growing back until I can get groundcover in there next spring. I thought of getting a load of mulch delivered and covering the dirt with a 3″ or so layer. Would that work to keep the weeds at bay?? Is there a better way? Second question — how would I go about ‘fixing’ this soil so it’s less compact, has some nutrients so that whatever I plant in there has a half-decent chance of surviving?? I’m new to gardening so would welcome as much detail as you can provide. Many thanks, and happy fall!!

(Answer)

Dear gardener, for a beginner gardener you are off to a great start!

Eliminating as many weeds as possible will prevent them from re-seeding. Dandelions in particular have a two year cycle before becoming full perennial weeds, therefore, eliminating as many as possible will reduce reoccurrence.

It sounds as if the area you are planning to work on has been left alone for few years. In addition to this, the fact that it is in a slope increases erosion which further makes the soil unfavourable. There are few different options you can tackle this situation:

  1. Apply cedar mulch to suffocate weeds. This will certainly work as it will suppress the seed bank from sprouting (although you have eliminated weeds, the soil will have plenty of weed seeds ready to germinate – sometimes they remain dormant for years as there are limited food, water and light resources and then sprout when conditions are better. The only problem with this solution is that you are not amending the soil to improve the planting conditions.
  2. Apply compost as mulch. I usually would recommend placing a layer of newspapers underneath, getting it wet and then applying the mulch on top. In your case however, I am afraid that it will all slide down the slope (not sure how severe is your current slope is).
  3. Apply compost and cedar mulch on top.

Organic matter (compost) has the capability of changing the soil structure and nourishing the soil at the same time attracting beneficial insects that will further improve the soil. Depending on what kind of groundcover you are planning to install, these will over time stabilize the slope and avoid further erosion.

Hope you found this information helpful and please feel free to email us if you have further inquiries.