Outdoor Practical Life: PNW Vegetable Garden – Soil Temp & DIY Soil pH Testing

DIY Soil pH Testing Tray with dropper, mason jar of water, mason jar of baking soda, mason jar of soil, and a spoon

“The importance of the work does not bother children, they are satisfied when they have done as much as they can and see that they are not excluded from an opportunity to exert themselves in their surroundings.  The most admired work is that which offers the greatest opportunities to each one.”

 – Maria Montessori

Outdoor Practical Life

We are moving right along in the process of starting our PNW vegetable garden so we thought we’d share some of what our family has been up to this week:  obtaining the soil temperature and DIY soil pH testing.

Thermometer on table

Soil Temperature Testing


  • Indoor/Outdoor Thermometer


To check the soil temperature, we grabbed our trusty Indoor/Outdoor Thermometer and placed the probe about 5″ deep into the soil to record an accurate temperature.  We obtained an AM temp and a PM temp to get an average soil temp for our garden site:

56 and 60 => 58 deg F

This is a good starting soil temp for us, and it assists our planning of what vegetables to direct seed and what to start indoors.

Next, we moved on to my favorite part:  DIY soil pH testing.  But first, I digress for a moment. 

Some Background on Intentional Work

It’s interesting how much our life experiences can really encourage our long-term interests.  My favorite class in high school was Chemistry.  The lab desk next to me was missing a huge chunk of countertop that my teacher jokingly referred to as the result of “a demo gone wrong”.  My teacher was inspiring and funny, and he was great at keeping the student’s interests up, with experiments that included shooting DIY bottle rockets off in the lobby.  He wore 15-year-old cargo pants that were no longer in style and he spent summers working in a lab that focuses on breast cancer research.  He inspired all of us to care about and like chemistry, which was pretty impressive for a group of upperclassmen who were too cool for school. 

Later in life, I got my B.S. in Chemical Oceanography and organic chemistry was my favorite lab.  It lasted a year total and I was always waiting for someone to blow something up, which never happened, but it was still cool to see all the physical and chemical changes that occur under the right conditions and with the right chemicals. 

I also had the privilege of working for two very accomplished and inspiring chemical oceanographers.  I really enjoyed that time spent in the lab. When our children are older, I hope that they will have the ability to participate in a mentorship in some area that they find as meaningful and inspiring as I did during my time as a research assistant and a high school chemistry student.  And if our kids can afford to live off of that salary, even better 🙂  My husband and I ended up having to further our education before that was possible.  

For now, our kids have us to mentor them, so we strive for meaning, inspiration, and fun in all that we do.  Now, back to the experiment.

Montessori kids obtaining farm soil sample with gardening tools

DIY Soil pH Testing


  • Distilled Water
  • Baking Soda
  • White Vinegar
  • Jumbo Dropper
  • Kitchen Scale
  • Mason Jars
  • Tray

First, we needed to test the acidity of the soil.

Dutch Oven with ice pack on top sitting on stove

Making Distilled Water for DIY Soil pH Testing

In order to test acidity, we also needed distilled water.  We opted to make our distilled water at home rather than purchasing it, using our dutch oven, a glass bowl, tap water, an ice pack, and the stove.  This is a great method if you only need a small amount of water, as we did for this experiment.  It’s very time consuming otherwise.

baking soda in dish sitting on kitchen scale next to measuring spoon and mason jar

Measuring Ingredients for DIY Soil pH Testing

Our oldest daughter measured 4 oz. of baking soda using our kitchen scale, and we added it to their Montessori tray.  

DIY Soil pH Testing Tray with dropper, mason jar of water, mason jar of baking soda, mason jar of soil, and a spoon

This tray is actually a family heirloom, given to my husband and I by his late maternal grandmother.  It’s made of Hellenic Steel and can stand up to all our toughest kitchen and Practical Life work.  I imagine it was probably meant for us to use as a decorative piece or for some light serving duty.  However, I think using it as a Montessori tray for educational purposes is not only a great way to honor the memory of family, but it also assigns it a purpose and a function in our home, something we strive for as minimalists.  Some of our most enjoyable homeschool experiences begin with materials we already own or have salvaged.  For us, it’s a great way to add meaning to the work.  Along the same lines, we’re naturally inclined to pass things on that we don’t use regularly.

Depending on the number and the age of the children, this could be an individual or cooperative lesson.  Our kids are very into cooperative play right now, so this experiment is set up for them to work on together.

Montessori kids working at a table on DIY Soil pH Testing

Procedure for DIY Soil pH Testing

In order to complete our DIY soil pH testing, our 4-year-old used the pipette to add distilled water to the soil sample until it formed a mud consistency.  Our 2.5-year-old then assisted his older sister in adding all the baking soda to the soil/distilled water mixture. and mixing it with a spoon.  There was no reaction when the baking soda was added, suggesting the soil has a pH greater than 6.  If it were to fizz, the soil most likely has a pH between 5 and 6.

Once they were done testing the acidity, our son spent about 20 minutes using the pipette to transfer the remaining distilled water between all the mason jars and he thoroughly enjoyed himself.  A pipette is also great tool to use for color mixing works.  Our kids love this thing.

Next, we moved on to testing the alkalinity of our soil, using 2 tsp of fresh soil from our garden site and some vinegar.  Our oldest used our kitchen scale again to measure 4 oz. of white vinegar and we set up our tray again, which I don’t have a picture of because I conveniently ran out of memory on my phone.  Luckily, we use Amazon Prime Photos to upload and store our memories so I can delete the media that’s maxing out my phone’s memory later.  There was no reaction when our kids added the vinegar to the soil sample, suggesting a pH less than or equal to 7.  If it were to fizz, the pH is between 7 and 8.

Conclusions About Our Soil

As I mentioned in our last post, we live on Jory soil, which can be slightly to moderately acidic.  Moderately acidic soil usually benefits from soil amendments such as lime, to increase the pH.  Overall, we can conclude that our soil’s pH is between 6 and 7, or mildly acidic to neutral,  which means our garden should be content with regular infusions of aged compost and some organic mulch; no lime necessary.

What’s the Next Step After DIY Soil pH Testing?

Now that our children have identified our soil temperature and our soil’s pH, we are moving on to the fun part:  establishing the bed.  

As our kids get all their tools together, in anticipation of some serious digging, we’re going to stop here.  We hope everyone is making the most of this unique time and keeping busy.  

Until next time, stay happy and healthy together!

More Outdoor Practical Life in the Garden


Starting a Montessori gardening program or looking to incorporate kid-friendly learning activities into your current gardening routine? Don't miss the opportunity to show children how to determine the soil temperature and DIY soil pH testing.  Learn about the soil at your garden site AND enjoy a gardening lesson. #montessori #homeschool #gardening #montessorigardening #montessorigardeninglessons