Fertilizing Soil in the Fall: Applying Organic Compost and More

Fertilizing Soil in the Fall: Applying Organic Compost and More

Compost, Vermicomposting

fall gardeningThe fall is the time to get a jump on applying soil amendments, including organic compost and worm castings.

Did you know?

  • Getting full benefit from natural soil amendments can take weeks or even months. Compost you apply in the spring might not be fully activated until mid-summer.
  • The soil in the spring stays muddy for quite a while. Dryer soil in the fall is easier to work.
  • You will have tons of garden and yard work to do in the spring. Getting your soil partially ready in the fall frees you up for spring chores.

What to Apply to the Soil

Typical natural fall soil amendments include:

  • Compost improves drainage and feeds valuable microorganisms.
  • Uncomposted organic scrap materials such as leaves break down into compost over the fall/winter/early spring
  • Nitrogen may be needed if a soil test reveals nitrogen deficiency. Compost adds nitrogen. Note: Growing legumes such as peas, beans, and alfalfa naturally fixes nitrogen in the soil.
  • Phosphorous soil amendments if needed.

You can save time by buying pellets or granular organic fertilizer. Some soil amendments have a specific mix of N-P-K (Nitrogen-Phosphorus-Potassium) on the package. Ask your garden center if you are not sure what you need.

If you compost with worms, harvest the worm castings. Worm castings are more valuable than regular compost because they contain soil-friendly bacteria. Fresh worm castings are ideal because the microorganisms are alive. Separating the worms from the castings will preserve your wiggly friends. Some may choose to just dump the whole vermicomposting bin on the garden and start fresh in the spring. The worms or their eggs will likely survive the winter.

You probably will not have enough worm castings to cover your entire garden. Worm castings can be mixed with other organic nutrient sources.

If you have a regular “hot” composter, dig out the finished compost.

Your local garden center or farmer might sell you compost. Uncle Jim’s sells worm castings by-the-bag. Also, you can use seasoned herbivore or equine manure. Fresh manure is fine in the fall. Fresh manure has months to break down in your garden before spring planting.

How to Apply Compost

Adding too much organic compost is almost impossible. Throw as much organic compost at your soil as you can! Organic matter makes up about 5% to 10% of soil.

Spread the compost evenly on the soil. On a large plot, dig the compost into the soil by tilling. Small kitchen gardens can be worked by hand.

Till roughly once in each direction. Leaving large clumps of soil helps fall fertilizing. Over the winter, the clumps will start to break down, draining soil amendments deeper into the soil.

Mulch the whole soil surface with hay, straw, or shredded leaves. Mulch reduces erosion.

The soil will be much flatter by the spring. Fine tilling might be all you need before planting.

How to Apply Uncomposted Organic Material

If you do not have enough compost, till uncomposted organic matter to the soil. You can use a combination of composted and uncomposted organic matter.

  • Find leaves on the ground that have changed color. Use a garden shredder, or run over them with the lawn mower a few times.
  • Throw in some used coffee grounds, perhaps from your local cafe.
  • “Green manure” means digging living plants into the soil. Cover crops such as alfalfa can be turned into green manure by tilling.


Gear up in the fall to save effort in the spring. Applying organic fertilizer in the autumn gives your soil plenty of time to self-renew. Composting with worms is faster than hot composting. Worm castings are also more concentrated and valuable due to their microorganism content. If you want to learn more about composting with worms, check out our blog, purchase our Red Worm Mix, and build or buy a composter. Composting with worms can be started any time of the year if you protect them from extreme cold.

Got questions? Visit Uncle Jim’s Worm Farm on FacebookInstagram and Twitter.

6 thoughts on “Fertilizing Soil in the Fall: Applying Organic Compost and More

  1. Am I understanding?

    I have some casting that I would like to put on the garden. Can I just lay them on top of the ground to help fertilize for next spring? I am wondering what to do with worm casting that I have now?

  2. Jeanne DeVries,

    Yes you can simply thinly broadcast your worm castings on your garden and even your lawn if you wish. You can either add your castings you have now in the fall or store them till spring.

    Uncle Jim.

  3. Question. Which worms thrive better when adding them to the traditional vegetable garden. Traditional trout fishing worms or red wiggles?

  4. Hello Jim,

    What about using shredded paper, my grandfather used to used shredded newspaper and coffee grounds. Don’t have that but plenty of office paper. Any idea if this will work for worms and composting?

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