How to Test Soil Ph & Amend Acidic or Alkaline Soil - Melissa K. Norris

How to Test Soil Ph & Amend Acidic or Alkaline Soil

By Melissa Norris | Gardening

Jun 03

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Learn how to quickly and easily test soil ph and amend acidic or alkaline soil for the healthiest plants possible. Healthy plants mean less work and that’s something we can all agree is a good thing.How to test soil PH and amend acidic soil

Growing your own food and taking care of your land is something high on every homesteader’s list. We take great enjoyment and satisfaction by growing our own food.. but we really get excited when we learn how to make our plants even healthier and more vigorous with a few simple tweaks.

Today we’re talking about how to test soil ph & amend acidic or alkaline soil to get the healthiest plants you can because healthy plants mean less work, can I get an amen?! And maybe more important, I’ll be discussing the mistakes to avoid.

This is Part 2, if you didn’t catch Part 1, go here now to get the 6 Natural Fertilizers to Improve Your Garden Soil & Increase Your Harvest with Healthier Plants. That’s the basis of what we’re building on in this post/episode.

Testing Soil Ph & Mistakes to Avoid when Amending Soil

Listen below to  Episode #135 of the Pioneering Today Podcast, where we teach families how to grow, preserve and cook their own food using old-fashioned skill sets and wisdom to create a natural self-sufficient home, with, or without, the homestead.

The first thing you need to know is if your soil is acid, neutral, or alkaline. Different plants prefer different soils because the correct soil ph for each plant allows it to absorb the needed nutrients to grow and thrive.

How to Test the ph Level of Your Soil

Finding out the ph level of your soil is fairly easy, but in true homesteader fashion, we’ve got options y’all. Here are a few soil testing methods:

  1. Lab Test: This method will give you the most accurate ph readings. To know the exact ph level you’ll need to have a lab test. Most county extension offices will test your soil  (except mine, last time I called in they didn’t offer it, hoping that changes sometime soon). This option will give you not only your ph level but also the levels of other minerals and nutrients in your soil. I use, they offer a detailed report for much less than other sources.
  2. Soil Meter: If you’re only after the ph level of your soil, these handy little meters are pretty inexpensive, they cost less than $15 and allow you to test multiple spots in your garden, planting containers, etc. Grab this 3-in-1 soil meter to test away.
  3. DIY Soil Test: Here’s a DIY soil test from the Old Farmer’s Almanac. That post will share a few methods, but one I’ve seen many people try is using vinegar and baking soda with a soil sample to let you know if your soil is acidic or alkaline. Unfortunately, this method is not going to give you exact levels, only general guidance if your soil is acidic or alkaline. So while it may show you your soil is acidic, you have no idea if it’s borderline or really acidic.

I haven’t used the DIY at-home testing method, I already know the soil in the Pacific Northwest is slightly acidic due to the needles from the evergreen trees and our heavy rainfall, so I make necessary amendments.

How to Amend the ph Level of Your Soil

There are two main ways to amend the ph level of your soil.  I’ll also share some alternatives we’ve used with good success, because I’m friendly that a’way).

How to Increase the Acidity of Your Soil

If your soil is alkaline and you need to make it more acidic, use elemental sulfur. Organic gardeners use elemental sulfur to decrease the ph level (remember, the lower on the ph on a ph meter the more acidic). Take care you use elemental sulfur and not aluminum sulfate when purchasing.

Important caution note: When lowering the ph level of your soil to make it more acidic, never try and lower it more than 1 ph level on the ph scale in a given year. Take care to read the instructions on the sulfur you use to make sure you don’t apply too much and if needed, do 2 applications over the year instead of all at once. This is a slow level, long-term process, have patience and be the turtle here, not the hare.

Another option for increasing acidity is the use of peat moss.

How to Decrease the Acidity of Your Soil

If your soil is too acidic and you need to make it more alkaline, use lime or calcium. There are varying points of view on using lime (made from crushed limestone) vs. ground-up oyster shells. Both will increase alkalinity but if your soil already has a high magnesium level, you DON’T want to use lime. Instead, use the ground-up oyster shells –>  click here for my recommended resources.

Whichever of the above-mentioned soil amendments you use, it’s best to work it into the top 6 inches of soil. Doing a simple top dressing where you just sprinkle it on is not as efficient.

You can also use wood ash to raise the alkalinity of your soil.

A word of caution: no matter what you’re using to amend your soil, it’s important you understand how it works, what your current levels are, and the appropriate amount to use for YOUR soil based on the tested levels. Grab yourself a ph testing kit (mentioned above) and keep those ph test strips handy so you can continually monitor the ph range of your soil throughout the year.

Do Coffee Grounds Make Soil More Acidic?

This is an area of great debate with gardeners. The short answer is no, using used coffee grounds isn’t going to significantly raise the ph level of your soil.

BUT using coffee grounds can be a great soil builder and natural fertilizer. This study, done by a Lab for Sunset magazine, has a great break down of how coffee grounds improve your soil. Most notable is the phosphorus, potassium, magnesium, and copper levels.

In summary, the available plant essential elements, which will be substantially improved where the coffee grounds are used as a soil amendment, include phosphorus, potassium, magnesium, and copper.

I have used coffee grounds for years on my blueberries, raspberries, and tomatoes. One key thing to note is to make sure you spread them out in a thin layer and work it into the soil or mulch. It’s also recommended to keep the coffee grounds to 25 to 35% volume when mixing it in with your mulch or soil.

Wet coffee grounds will clump together and can develop mold as well as create a barrier for moisture and air circulation. (Source)

If you don’t want to deal with changing the ph level of your soil, then simply pick the plant varieties that naturally grow well with your soil’s ph level.

Most plants will get along fine with ph levels between 5.5 and 7 without too much of an issue. There are some exceptions to this generality (isn’t there always) so I’ve listed out the plants below for you that really need the higher acid levels to grow well. Of special note is blueberries, they are one of the most acid soil loving plants out there.

If you’re planning on raising as much of your own food as possible, you don’t want to be limited to the plants that only grow well in one type of soil. No, my friend, you and I, we want all the goodies in our larders come winter.

How to Grow Both Acid and Alkaline Loving Plants Together

The strategy we use here on our homestead is to micro-manage the soil ph levels according to the crop.

Say what? Let me break it down.

I plant my high acid-loving plants together so I’m only amending the soil for acid in one area.

This is my variation of companion planting based on soil preference. I plant my rhubarb between my blueberry plants and my raspberries are one row over from my blueberries.

Because these are perennial plants, they’re staying in the same soil and spot year after year, I amend the soil once in the spring by adding fir mulch. This doubles as my mummy berry (a fungus that infects blueberries) protection as well as moisture retention in the summer months since blueberries have shallow roots.

When I plant beets, I add a small amount of wood ash to that row only. When I go to plant something else there the next year, the ph level has pretty much gone back to its normal slightly acidic range.

Fruits and Vegetables That Prefer High Acidic Soil

(Acidic soil is 0 to 6.9 ph level, with 4.5 to 5.5 being considered high)

  • Blueberries
  • Cranberries
  • Currants
  • Elderberries
  • Peppers
  • Potatoes
  • Rhubarb
  • Raspberries

Up close vertical shot of pickled asparagus in a jar.

Fruits and Vegetables That Prefer Alkaline Soil

(Alkaline or sweet basic soil is 7.1 to 10 ph level)

  • Asparagus
  • Beet
  • Leek
  • Marjoram
  • Parsnips

How to Amend Your Pasture Soil

Because our soil is slightly acidic we use lime to alter the ph of the soil every few years. Generally, we do it about every 2 to 3 years in the early spring.

For pasture amendment, you’ll do a top dressing method, because we’re not going to disc up our field.

We use a hand push broadcast spreader to evenly distribute the lime over the pasture. We don’t have a tractor so this is a low-cost way to spread it out more efficiently than doing it by hand.

It’s important we keep our pasture soil in tip-top shape as its the building block for the feed our animals eat and, ultimately, what we eat come harvest time.

Are there any methods you’ve found to be effective or work well in your garden and homestead?


About the Author

Melissa K. Norris inspires people's faith and pioneer roots with her books, podcast, and blog. Melissa lives with her husband and two children in their own little house in the big woods in the foothills of the North Cascade Mountains. When she's not wrangling chickens and cattle, you can find her stuffing Mason jars with homegrown food and playing with flour and sugar in the kitchen.