Amending Your Soil Organically Between Seasons ~ 5 Things to Do


This is by far one of the most commonly requested topics when I ask people what they want to learn about gardening. It’s probably because we all know that good soil means happy, productive plants. The truth is, the best soil is carefully nurtured and transformed over time. It’s not really something you can buy in a package and then replace every season. While I do not claim to be an expert, I’ve been asked to share what I do to keep my soil going in the garden all year long.

Remember, here in Southern California, we have the opportunity to garden every single month of the year. Yes, it can be exhausting for both the gardener and the soil, but with some of the practices I’ve outlined below, I have found the soil just keeps getting better.

#1 Top with Compost

This is the number one, most important thing we add to the beds at the beginning of each season. Currently, Sam and I don’t make enough compost to cover our whole garden, so we supplement with bags of organic compost from our local nursery. For our small space we are big fans of compost tumblers, but this year we are expanding our compost system in hopes of being able to generate enough for our whole garden.

Update! Our new compost system is up and running and we love it! Read all about compost here → Compost 101

Let’s Talk Compost!

Why do people say “aged compost”??? Don’t get confused! The term “well aged” or “aged compost” is used a lot in the gardening world incorrectly but with good intentions. Compost is simply decomposed organic material, so using the term “aged” almost feels redundant because true compost is finished—no more ageing left to do. It smells earthy, has no discernible scraps, and is rich and glorious. It has finished the process that turns our scraps into treasure—essentially being “aged” by definition. Compost should never smell bad. If your compost smells bad, chances are it is not composting correctly.

This is our DIY backyard compost bin. We have two on our side yard.

It’s my opinion that the term “aged compost” is often used incorrectly but with good intentions because there is a fear that gardeners are using fresh chicken or cow manure to top off their gardens. Compost is not manure—just to clarify. Here are some excerpts from the WI Master Gardener’s website that offer some insight on manure in the garden:

“Because of the potential of transmitting human pathogens, such as E. coli, fresh manure should never be used on fruits and vegetables. If you are growing crops where the edible portion is in contact with the soil (such as carrots, beets, or potatoes) fresh manure applications should be made at least four months prior to harvest.” 

“Composting manure eliminates some of the problems of fresh manure — including the odor. It is lighter and easier to haul since it has less moisture, and the composting process may kill weed seeds and pathogens if the pile heats above 145°F.”

If using manure in the garden, it should be aged or composted for the reasons quoted above. So, you can see why the term “aged” is very important, but probably better suited to the discussion of manure or “composted manure” rather than compost. Compost does NOT need to contain manure of any kind to be true compost. We do not currently add any manure to our gardens or compost.

#2 Leave Small Roots to Decompose

When you go to clear out your beds, clip your plants off at the base and leave the root ball in the soil to decompose. This is also known as leaving the roots to rot “in situ.” As the roots breakdown, they become part of the rich, organic matter in the soil. This is especially true for plants known as “nitrogen fixers” whose roots are known for storing nitrogen in nodules that will release nitrogen back into the soil as they decompose. Some examples of “nitrogen fixers” would be peas, beans, most legumes, clover, etc. In fact, check out the picture above for a look at the nitrogen nodules on the roots of my pea plants last year. Aren’t they amazing?! I left these little roots in the bed to decompose and hopefully release some of the nitrogen back into the soil.

Related Article: What Type of Garden is Right For You?

Important NOTE: it has been said that  if nitrogen fixing plants are allowed to produce their beans, crop, etc. that the plant has actually started to used up all the nitrogen that was stored in those nodules….thus there would not technically be nitrogen in the nodules. Studies also say you can look at the color of the nodules to determine if nitrogen is still present. This information could use an entire article in itself, so I’ll stop there. Just some food for thought.

If the roots are extremely large, I do take them out for chopping and adding to my compost bin. The only roots I leave are really the smaller ones. As you garden more, you’ll start to observe which roots decompose well, versus which ones just cause problems for new plants and get in the way.

*NEVER leave the roots of diseased plants. Dispose of those in the trash.

#3 Additional Organic Amendments

(Updated November 2021) The BEST way to know what amendments to use is to have your soil tested. A soil test will allow you to choose amendments with the correct qualities for your garden. I don’t use ALL of these listed. Instead, I’ll go by my soil test results. That being said, there are some gentle organic amendments that carry very little risk of burning your plants that you can opt to use….but if your soil is already balanced, you might not need amendments at all!

Recently, I have been experimenting with some gentle, organic amendments that can help revitalize the soil. By “gentle” I’m referring to those numbers you see on fertilizer packages—the N-P-K numbers. Have you ever seen those? Here’s a brief breakdown of what that means:

N (Nitrogen) -this is responsible for creating lush greenery and foliage.

P (Phosphorus)– essental for blooming and fruit production.

K (Potassium)– this is also called “potash” and can help the plant cope with environmental stressors, build sturdiness, and be more relaible with fruit production.

So, when you look at a bag of fertilizer, the three numbers listed refer to the N-P-K levels. There are many different organic amendments to choose from, depending on your soil needs. The following amendments are “gentle” because their numbers are low in those categories. Whenever adding amendments to the garden, always follow the package instructions for each one.*It should also be noted that different brands can have different N-P-K levels for the same kind of product

Gentle Organic Garden Amendments

Kelp Meal 1-0.5-2

Alfalfa Meal 2.5-.5-2.5

Azomite 0-0-.02

Worm Castings

I’ve also been adding worm castings, which can be purchased at your local nursery in bags. Worm castings are essentially the waste of earthworms after they have consumed organic matter. It’s really good for soil. You can also learn to vermicompost yourself to get your own worm castings. Years ago I tried vermicomposting, but eventually could not upkeep it in addition to everything esle in the backyard. I hope to pick it back up one day, but for now our soil has very healthy worm populations so I’m satisfied. In general, worm castings are something you can add in the beginning of the season and throughout the growing season without needing a soil test.

High Nitrogen Organic Amendments

Last year we did a soil test as a little checkup, and it said we were pretty low in Nitrogen. I had been conservative about too much Nitrogen because that can result in lots of leafy growth and less production, but it seems I was too conservative. I started to amend my beds with one of the following Nitrogen options before planting:

Feather Meal 12-0-0 (we used Down-to-Earth brand)

Cottonseed meal 6-2-1 *I only use this if the plants in the bed like acidic soil, or if your PH is low. Another reason you should get a soil test

Amendments for Bulbs, Tubers, and Corms

Many flowering bulbs benefit from phosphorus, so bone meal is a great amendment. I have also used it for my peppers and they seem to like it as well. Great for anemone flowers, ranunculus, dahlias, and tulips too.

Bone meal 4-12-0

Really important!!!!!! Pets love to sniff out garden fertilizers and amendments. Watch them carefully and, better yet, keep them away. I do gently mix my amendments into the top few inches of soil which also helps to disguise them. 

#4 Transplant with Mycorrhizae

I’ve been using mycorrhizae in the garden for the last few years now and have LOVED it. I was skeptical at first, but the results have made me change my mind.

I write more in-depth about the reasons for using mycorrhizae in my “Tips for Stronger Seedlings” article, but they essentially help plants build stronger root systems. My favorite product at the moment is a granular mycorrhizae from Plant Success Organics. I simply sprinkle a little of the mycorrhizae granular in the planting hole before transplanting a seedling. Use my code: randi15 for 15% off your purchase from Plant Success Organics!

Related Article: 5 Herbs You Should NOT Start From Seed

#5 Mulch

It’s not techinically an amendment, but using mulch in your garden can be extremely beneficial. How do I mulch? I go into more detail in Let’s Talk Mulch! Mulching a Backyard Garden but essentially you can use a variety of organic materials such as dead leaves, grass clippings, stalks from old plants, or even wood chips from pruned branches. Mulch is basically a layer of organic material that you would spread over the surface of the soil in your garden.

♦ Mulching allows the soil underneath to retain more water.

♦ It protects the base and root system of the plant from extreme temperature fluctuations (like a heatwave or freeze).

♦Mulch can eventually breakdown and add nutrients back into your soil.

So those are the 5 things we do for our garden to keep it thriving season after season. Remember, building healthy soil  is a process and takes time. It also is fun to experiment and see what works for your garden.

⇓ What are your favorite tips for building healthy soil in your garden? ⇓

Meet Randi

Urban gardening is my jam. I’m Randi, California girl who obsessively gardens to grow food and flowers around my urban home. Seasonal, simple living is what inspires me~ I hope it will inspire you too. Join me in crafting a life and home connected to the garden Read More>>>>

For Growers & Gardeners from High Mowing Organic Seeds