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
Thank you. I enjoyed this. I cut my giant sunflowers at the base, do you think they will have too large of root systems? Also, I’m planting pretty densely in my veggie bed so I find it difficult to mulch. Are you mulching 5 inches deep or so but also making sure it doesn’t touch other plants. I’m also having trouble discerning if something is dying or it’s diseased. Like the lower leaves on my sunflower got spots. I chopped them off and let them dry out and threw them into the compost because I need more dry carbon material, but now I wonder if it had a spore of some kind. I’m not turning or wetting my pile so I definitely have a COLD pile. ?
Anyways, great tips as always. So excited to watch my soil health change over time.
Hi Lyndsay! I would say the sunflowers might be too large and, when in doubt, remove the roots. Leaving thin, feathery roots is great but in the grand scheme of things root decomposition plays such a small part. In regards to mulch, we only do a small layer of a few inches. If your plants are densely planted, they technically end up protecting one another as they grow in…so it kind of serves the same purpose. Whenever I have dead leaves I just use them as mulch for more vulnerable plants….like newly planted seedlings that could easily dry out because they aren’t established. When it comes to the spots on your sunflower leaves (or any leaves really)and composting, always err on the side of caution. It’s just better to be safe than contaminate your garden. I hope that helps!!! I think you are asking all the right questions! As you gain experience you’ll start to know for sure when things are done or “dead.” I have limited space, so usually if something is done producing it loses it’s spot in the garden fast! Hahahaha
Thank you so much!
Do tomatoes have small or large roots?
My tomato plants get base trunks that are almost as big as my wrists. I usually pull out the whole plant 🙂
What type of mulch would you suggest for a backyard organic garden in LA? I noticed that mulch at Home Depot, etc. seems to by dyed with toxic materials so that wasn’t very appealing to me. Thank you!
Good thinking Carly! I agree with you! You can always use your own yard clippings and dead stalks (like corn stalks) to chop and mulch your garden. This is called “chop and drop.” Any dead leaves you can rake up and use as mulch too. In fact, if you check out my most recent compost article, I have a link to a simple wood chipper we purchased in order to be able to use our own tree prunings for mulch. Another great option is straw (not hay—because hay could have pesky seeds) from farm supply stores. I’d also check bulk landscape companies for any organic wood chips if you are looking for a more uniform, clean look. A last option would be using compost as mulch. If you top dress your garden with compost it can act as a mulch AND feed your plants. I even think there is an organic product by kellogg (you can find at most garden stores) that says it is an amendment but also acts as mulch. I hope that helps! Thanks for reading 🙂
Thank you so much for the quick and detailed reply! I really appreciate it. I actually have another question for you. Is there any big disadvantage to starting seeds in potting mix/potting soil instead of seed starting mix? I already have potting mix and would like to be able to avoid the added expense of a specific seed mix if possible. Also, I watched your video on feeding seedlings. What is the advantage to using the tray soak method instead of applying from above with a watering can? (Again, trying to save costs anywhere possible since I am laid off due to Covid shut downs. Trying to work with what I already have.) Thank you! Love your blog!
Hi! I am sorry to hear about your job. Using what you have is definitely possible! I think gardening is very flexible and things can be done different ways. In regards to the potting mix: yes you can. From experience, I find seed starting mix to hold moisture more evenly have less potential fo fungus, and roots seem to grow more vigorously because it is light and fluffy. Regardless, seeds will germinate in most any soil, and we sometimes even direct sow in the garden. For the tray feeding: you can water from above. The tray helps the pots take up exactly the amount of water needed and will allow the food to go directly to the roots more efficiently. That being said, it’s all really just preference. Also, watering from above can wash out delicate seeds/seedlings. As long as you are gentle, go for it! 🙂
Carly, I wanted to re-visit this comment as I (finally!) put together some ideas for how we mulch around our garden. Recently some gardeners have said that you have to be careful with straw and make sure it isn’t treated with chemicals, so even more reason to make your own mulch or know the source! You can read the article here: https://freckledcalifornian.com/2020/12/16/lets-talk-mulch-mulching-a-backyard-vegetable-garden/