Soil Amendments for Raised Beds

The dirt! What are soil amendments and why are they important for raised beds? Last year, even though we got a fair crop yield, we felt that the soil as it was newer and hadn’t “aged” yet, was limited in fertility. Soil fertility is very important – it’s a measurement of how nutrient dense overall what you’re working with.

That’s what this article will be about, testing your soil and discovering what it needs to thrive for all those bountiful veggies. That’s why it’s important to do this early on, so you’re not disappointed later. And I will be going over the most common soil deficiencies and how you can correct them.

Great? All right, let’s get to it. The first thing to focus on regarding the soil, is the texture.

Is There an “Ideal” Soil Type?

Almost unanimously, the ideal texture type and makeup of soil should be classified as “loamy”. Checking your soil composition is a little bit of a science…There’s a “golden ratio” you want to strive for…It is about 40 percent sand, 40 percent silt, and 20 percent clay. If you’re in that neighborhood, you’ve got what’s known as “loam”.

The texture is important to measure too, soil that is too crumbly will not bode well, too sandy , same thing.

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amending soil

When in Doubt, Test…

Veteran gardeners always have an arsenal of tests to check their soil’s composition.  First you can take a handful and compress it in your hand. If it doesn’t hold its shape and crumbles without any outside force, you probably have a little too much sand. If you poke the compressed ball with your finger and it doesn’t fall apart easily, your clay ratio may be too high.

If you’re still unsure, there is another approach you can take, it involves separating each ingredient. Dig down in your bed, at least below 6″, and drop a cup or two of dirt into a jar of water. Today’s mason jars work great for this as they have measurements on the side. Fill the jar with water up to at least 2″ from the top. Shake the jar up vigorously for a few minutes, then let it set until you see it separate into 3 different layers.

It may take up to 2 days to get the most accurate result. The top one is clay, the next is silt, and the bottom layer is sand. This way you can easily gauge what your ratio is, and act accordingly to balance it out, if need be.

taking a soil sample
That’s real Georgia red clay, peeps…

Here is the result of my soil test to give you an idea of what it looks like. I dug below the topsoil – at least 8 inches – to reach that layer. The image to the left is after an hour, and the right image is the full 48 hours later. Notice how dense that clay layer is, I wasn’t kidding when I talked about it earlier.

Soil sample tests are also available if you have a local agricultural center nearby…they do charge to do this, how much I can’t say. Or you may prefer to do the test on your own. No problem, you can easily acquire a kit of your own like one of these….

Luster Leaf Products Soil Test Kit, GreenLuster Leaf Products Soil Test Kit, GreenSee on AmazonLuster Leaf Rapitest Soil Test KitLuster Leaf Rapitest Soil Test KitSee on Amazon3-in-1 Soil Test Kit, Soil Moisture Meter3-in-1 Soil Test Kit, Soil Moisture MeterSee on Amazon

How much water is present in your soil is another factor.  having elevated beds in the first place helps keep the soil from absorbing too much water and helps maintain good drainage.

Some soils are very lacking in nutrients, so it’s up to you to build them up organically.  One to two weeks prior to planting, you should add a good amount of fertilizer to your garden. Of course, if you need any advice, you may be able to get some tidbits from the local nursery owner. Many of them are glad to help!

Now that you have some idea, time to look at some of the common fixes.

Corrections for Sandy Soil

Sandy soil will be overall difficult to work with and grow anything, as it’s comprised of large particles, it remains very dry, it will be very difficult to retain moisture, and what does flow through will hardly make it to where it needs to be – to developing root systems. Soil with too much sand present is also lacking in fertility.

If your soil sample has too much sand,  it’s best to add some peat moss or compost.Both of these can be sourced for low cost. There are a few crop types that may do just fine in sandy soil -like taproots- but most prefer the types with more moisture that you can only get from the addition of organic matter.

Corrections for Too Much Clay

Soil that is heavier on the clay side retains moisture better than sandy, as well as more nutrients, but there is that problem of If you’ve got too much clay present, it’s more likely to cause waterlogging. Because it’s so dense, it can be difficult to dig into. Peat moss, sawdust, grass clippings, and pine bark are all amendments that can help. Peat moss is a common addin that helps the new ingredients to infiltrate the mixture better.

amend raised bed soil
For this, as well as the sandy scenario – Let it sit up for awhile. About a week or two after planting, you should continue or a regiment to add fertilizer. In the first few weeks of being in the soil, the seeds you’ve planted are taking in all the nutrients quickly – but then when they run out, you’ve got to replenish it.

You can space out the length of time you add fertilizer after the plants’ growth is more apparent, as they will gradually need less of it. I use Miracle-Gro, which I mix in a gallon of water and dispense at the proper time.

Check the Soil Ph

You should also be testing your soil’s Ph level….the “ideal” is about 6-7. If you’re not familiar with the Ph scale, anything from 1-5 is acidic, 6 is neutral, and anything above that is alkaline. You could probably get someone at the local plant nursery to do a test on a soil sample at a small fee. This could tell you all you need to know to go forward in improving the soil quality, what to focus on, and what not too, as if you change the ph level too rapidly, the plants could suffer shock. Don’t forget there are soil Ph tests kits available too!

Garden Tutor Soil pH Test Kit (3.5-9 Range) | 100 Soil pH Test StripsGarden Tutor Soil pH Test Kit (3.5-9 Range) | 100 Soil pH Test StripsSee on Amazon

Like this one I found. It’s not too different from the test kits i would get for my aquarium, where there was an individual liquid product to test the Ph, nitrate, nitrite and ammonia levels.

6 or 7 is slightly acidic which is good to strive for. Most of the vegetable crops you’ll be planting will do fine at this baseline. If your ph is not optimum, sulfur can lower it – epsom salt (magnesium sulfate) dissolved in water,is a good source – but only if the soil is deficient in this area.. otherwise results may be minimal at best..

Adding Compost and Mulch

Organic matter is another good soil amendment. There are many ways to acquire it….one of the best ways is compost. Compost sources could be anything like apple or potato peels, melon rinds, things like that we normally throw away but when they start decaying can become a great nutrient source.

Learning to compost well is a skill – you may have to be judicious when you sort your trash but there are no downsides… It’s free or cheap, you do want to be sure to push things like food scraps deeply into the soil (you don’t want to attract nuisance animals, right?)

Mulch is another great component. Mulch is a cover crop that is best applied in the wintertime to stave off potential damage from frost, keep nutrients locked in and prevent water from drainage. Grass clippings, straw, dried leaves and broken branch limbs are good examples of organic mulch that can be easily acquired.

Adding Aged Manure

Some of the soil we use in our beds is made from aged manure. Which you probably know, in crude terms…is mostly animal feces (specifically, livestock/farm animals.) Manure has a very heavy abundance of nitrogen, which is an essential nutrient but too high an amount could burn your crops, so that would be something to not use, at least initially. About 6-8 months is needed before it can become usable. Wait and compost it first, allow the odor to dissipate – as it does so it will darken in color.

Since I have laying hens, this would be an option for me; however, I haven’t had them long enough for their manure to be usable (Ask me about this in a few more months.)

soil additive limeAdding Lime

Lime or calcium-dense products like gypsum can elevate the pH of the soil, as well as help balance out the calcium deficiency. Here is a bag we picked up not too long ago to add to our bed that had the potatoes – we discovered that (even though the yield was fine) the soil in that particular bed was somewhat lacking.

Of course, that means we will have to wait until next growing season as we got busy with something else and ran out of time to start a new crop after harvesting all of the first.   I will gladly provide an update when the time comes after adding some lime.


Well, I think we covered a lot of ground here …(pun intended) Hope this comprehensive guide tells you everything you need to know about how to amend your soil and make its quality the best possible.

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