Adding compost to no-till bed covered with straw

(Question)

Hi!
I would love to learn more about no-till gardening and naturally boosting soil health with my backyard veggie beds. I have not been tilling for a few years and I have the beds covered in straw/leaves.

My question is how do I add compost to the beds without tilling? I have homemade compost.

Do I remove the straw and just leave it on top of the soil and re-cover the straw on top?

Should I gently rake it into the top layer of soil?

Should I sift the compost to make it easier to spread or leave it as intact as possible so as not to disturb the microbes?

thank you!

(Answer)

No-till gardening maximizes the health of garden soil and minimize weeds, creating a much better environment for growing vegetables.  For example, preserving physical soil structure is important – this impacts drainage/retention of water, erosion, and crusting on the soil surface.  No-tilling also encourages earthworms and microbes – which contribute nutrients – to thrive.  Large quantities of mulch are used to enhance soil quality and suppress the growth of weeds.  It will take a few years to achieve healthy soil through no-till gardening.  Ultimately, though, you will not have to water or weed as much as in your conventional garden.

On the other hand, tilling soil can harm the soil, for example it can promote erosion, bring weed seeds to the surface, and disrupt soil aggregates (clumps) – the latter contributes to soil compaction.

To get your garden bed ready for planting, go ahead and gently use a rake to incorporate the compost.  Remember that no-till gardening is a years-long process, and at this point, don’t worry about disturbing the surface of the soil.  You’d be doing this to enhance the overall health of the soil – e.g., by aerating the soil and adding nutrients (your homemade compost). There is no need to sift the compost.

Other issues to think about with your no-till garden include the following:

  • Is the soil pH optimal for your crops?
  • Is drainage good enough? If not, you may need to add sand, organic matter or other materials to enhance drainage.
  • Prevent soil compaction – don’t walk on the planting bed.
  • Keep the soil covered – use mulch and lots of it – apply 2.5-5 cm (1-2 inches) each year. Your homemade compost will do nicely!
  • Move the straw mulch layer to the side in areas where you plant your seeds/plants. Once the plants have emerged and are growing well, place the straw cover back in place or incorporate fresh mulch around the bases of the plants.  While straw makes a great cover for the soil, it does not add nutrients.
  • Some experts recommend seeding cover crops into the soil in the autumn, after growing season. These crops add nutrients to the soil and suppress weeds.  Grains (e.g., rye, oats, wheat, annual grasses), legumes (e.g., peas, soybeans, clover, vetch), and other plants that germinate quickly (e.g., buckwheat, mustard, alyssum) are among the cover crops used.  Remember too that a good mulch will also add nutrients and takes much less time than cover crops!
  • Clean up the garden bed in the fall – cut plants back to the soil line, leaving the roots to decompose (don’t pull them out). Get rid of plant debris that could harbour insects/disease.
  • Before starting a no-till garden, it is often recommended to get rid of existing vegetation by smothering the area with layers of newspapers or cardboard (about a year in advance of starting the garden). However, it sounds like you do not have an issue with too many weeds or other undesirable plants that will compete with the vegetables.

There is lots of great information on-line about no-till gardening, here are a few links:

Charles Dowding is well-known in the UK for his “no-dig” gardening expertise.  There is a lot of helpful, free information on his website – including his blog and Beginner’s Guide.

All the best with your no-till garden!  Have fun!!