Gardening Hack: Testing Your Soil's pH

Knowing whether your soil is neutral, acidic or alkaline makes a big difference in how your food plants produce and how your flowers flourish. Use this gardening hack to get an idea of your soil's health with simple items from your kitchen.

Check Your Soil's pH

To start soil testing, grab two glass bowls, a spoon, your baking soda, some distilled water, and your vinegar.

Gather spoonfuls of dirt from your gardening bed and place them in the bowls. You should test each bed separately because each location will probably need its own soil amendments

  • Pour distilled water into one of the bowls and stir until it turns into mud. (Use distilled water rather than tap water because distilled has a neutral pH.)
  • Add a couple of spoonfuls of baking soda to the slurry and stir. If it fizzes, you know you have acidic soil.
  • Pour a little vinegar into the other bowl and stir until it's muddy. If it fizzes, you know you have alkaline soil.

If neither test produces a reaction, you have neutral soil and your plants will be very happy!

Adding compost is the best long-term way to balance your soil, whether you have an acidic or alkaline garden. It's always best to add compost at the end of the growing season and mix it in deeply to let it really mingle with the dirt. Of course, you can add compost anytime, but it takes a while to have full effect.

What if you want a quicker fix? Here are some ideas to help your soil get closer to neutral in a shorter amount of time.

Soil Amendments for Alkaline Gardens

Aluminum sulfate or iron sulfate are the recommended amendments for alkaline gardens. Elemental sulfur is also effective, but takes much longer to make an impact and you should really add it in the fall when you put the gardens to bed. You might just have to break down and buy one of these if you're trying to fix alkaline dirt because there aren't too many items you might use around your home that can be repurposed in the garden.

Pine needles, shredded leaves and sawdust are great mulches for plants growing in alkaline soil. These break down gradually through the action of rain or irrigation and change the soil's pH over time. Don't overdo, though, or you may turn your garden acidic

A lot of people recommend sprinkling used coffee grounds around garden plants to fix alkaline soil, but this isn't a particularly effective method. Most of the acid has been leached away through brewing so little is left to balance your soil. However, if you have container gardens or small plots, "watering" with cold, full-strength coffee once a week is helpful to lower the PH.

Soil Amendments for Acidic Gardens

Dolomite lime, which you can pick up at any gardening center, is a good investment for acid soils. Ground oyster shells are another healthy soil additive. However, if you want to be thrifty and self-sufficient, use your own eggshells to raise the pH.

Each time you use an egg, rinse the shell thoroughly and let it air dry completely. (This is to keep your kitchen from becoming smelly and growing nasty bacteria.) Crush and place in a lidded container. When you've collected enough shells, run them through your food processor or blender until they're completely broken up. Then, mix the eggshells into the soil around your plants, trying not to disturb the roots. 

Hardwood ashes are another acidic soil amendment, but these should be added in the fall and mixed into the dirt very well to prevent plant burn.

Whether your gardens are acidic or alkaline, it pays to balance the soil so all your plants can thrive. Testing is only the first step, but you can find out what kind of soil you have just by using common items from your kitchen. Then, the work begins!