If you want your houseplant to thrive, you need to have the right soil. Part of having the right soil is having the right soil pH.
But how can you know what soil pH is right for your indoor plant? In this article, we will break down the difference in soil pH, and help you determine if you have a houseplant that likes acidic soil.
What is Acidic Soil?
Acidic soil is soil that has a lower pH. Most houseplants like soil with a neutral pH, or a pH between 6.5 and 7.0. Acidic soil has a pH under 6.5. On the other end of the spectrum, alkaline soil has a pH over 7.5.
What Houseplants like Acidic Soil?
The majority of indoor plants like potting soil that is neutral or slightly alkaline. However, there are house plants that like a more acid soil. If you’re looking for acid loving plants (also called ericaceous plants), here are a few to choose from:
- African violets (pH 5.8-6.2)
- Boston ferns (pH 4.0-6.5)
- Cactus plants (pH 5.0-7.0)
- English ivy plants (pH 5.5-6.5)
- Monsteras (pH 5.5-7.0)
- Philodendrons (pH 5.0-6.0)
- Peperomias (pH 5.0-6.0)
- Crotons (pH 4.5-6.5)
How Do I Dnow if my Houseplant Soil is Acidic?
It can be hard to know if your plant has acidic soil or alkaline soil. It’s not something you can tell just by looking. Luckily, there are a few ways you can test your soil to see if it is acid soil or alkaline soil.
Testing with Baking Soda
One way you can test your soil is with baking soda. For this method, you will want to take 2 tbsp. of soil and moisten it with water. Then, add 1/2 cup baking soda to the soil. If your soil has a reaction, you have acidic soil. If there’s no reaction (think fizzing and foaming), you have alkaline soil.
Testing with a pH Meter
A pH meter is great for testing both your soil and water pH. You’ll want to follow the instructions for the specific meter you choose, but most simply require you to stick the gauge into the dirt and wait for a reading. Here’s the pH meter I’ve used for several years.
Testing with a pH Soil Testing Kit
A testing kit is another tool you can use to check your soil’s pH. Your test kit will come with test strips and specific instructions, but the general process will have you mixing soil with some water and applying to the test strip to determine pH. Here’s a great option for testing your soil.
How Can I Make My Plant Soil More Acidic?
If your acid-loving plant isn’t thriving, it might be time to adjust the soil pH value. Once you’ve tested your potting mix, here are some things you can do to create more acidic soil conditions for your plant.
Use a Commercial Soil Acidifier
One way to increase soil acidity is by using a commercial soil acidifier, also called an acidifying fertilizer. These products contain minerals like sulfur, and they will quickly lower the pH of your houseplants and garden plants soil. I like the Epsoma brand because it is organic and easy to use.
You can also use this product to turn your flowering hydrangeas blue!
Vinegar is an easy and affordable choice for reducing the pH of your soil mix. You will want to be very careful with vinegar, because using too much can be harmful for your plant.
To use vinegar to reduce pH, mix 1 cup of vinegar with 1 gallon of water. Use this mixture to water your houseplants and flowering plants. Here are some other ways to use vinegar to keep your plants healthy.
Making your own acidic compost is another way to create acid soil. Including things like pine needles, oak leaves, and citrus fruit to your compost will help increase its acidity.
To use this method, you can either add compost to your plant’s soil in small amounts over time, or you can repot your houseplant and mix in compost with your potting mix.
Use Sphagnum Peat Moss
Peat moss is another excellent and natural way to lower soil pH. For this method, you will want to place a layer of peat moss on top of your plant’s soil. As it works its way into the soil, it will gradually reduce the pH of your garden soil or houseplant soil.
Soil pH can be a tricky thing, and the challenge of getting it right can be intimidating. However, with a little research and effort, you can create the perfect soil conditions for your acid-loving houseplants. If you get the soil right, your indoor plants with thank you with lots of beautiful, natural growth.