The ideal blueberry potting soil is acidic, full of organic matter, and formulated to provide the perfect environment for the plant. But it doesn’t have to be complicated or expensive. Here I’m sharing my recipe for a simple and effective blueberry potting mix, plus a few of my favorite brands to try.
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For much of the world, the simplest way to successfully grow blueberries is in a container. Blueberries need a very specific environment to grow well, and most of us are not blessed with the ideal blueberry-growing conditions. Growing in containers is the perfect solution.
But what kind of growing medium is best for potted blueberries? Is there an affordable option without a lot of expensive or specialized ingredients?
In this article, we’ll discuss what kind of soil environment is best for blueberry plants. I’ll share how to make a simple DIY potting mix specifically for growing blueberries. I’ll also suggest a few other options, including some great commercially available mixes you can buy at various price points.
What kind of soil do blueberries need?
Acidity
Blueberries must be grown in very acidic soil, with a pH between 4.5 – 5.5. This is potentially the most crucial part of a blueberry growing medium because it directly impacts the plant’s ability to absorb nutrients.
Different nutrients become bioavailable at certain pH levels. At a low pH (acidic soil) the micronutrients iron, manganese, boron, copper, and zinc become more available for the roots to absorb. If the pH is too high, however, even if there is plenty of these nutrients present in the soil, the plant won’t be able to uptake what it needs.
Curious about any garden-related terms? Click on a highlighted word in the text, or visit The Fruit Grove Glossary to find out more.
It’s common for blueberry bushes to have micronutrient deficiencies because of improper soil pH. Chances are the problem won’t be solved by more fertilizer. Instead, look first at whether the soil pH is correct, and adjust accordingly. All of the commercial potting mixes I recommend here, as well as the DIY recipe below, have a pH in the ideal range for blueberries.
Learn more about how to adjust soil pH for fruit plants here: Soil pH for Fruit Trees: Why it Matters and How to Adjust It
Consistent Moisture
One of the most common reasons for blueberry bushes to die (or not fruit well) is inconsistent or inadequate moisture. Blueberry plants have very fine roots that stay close to the soil surface, so they can dry out quickly.
A mature blueberry bush may require as much as 8-10 gallons of water per day during the fruiting season. Your container blueberries may not need quite so much since the root system and size are restricted by the pot. But if you want blueberries, be prepared to water fairly frequently.
Drainage
Whether blueberries are planted in the ground or in a pot, they need good soil drainage. There’s a different between the roots staying moist versus sitting in soggy, waterlogged soil. The latter is a recipe for root rot, which is a quick road to plant death.
Learn how to check and improve soil drainage here: Soil Drainage for Fruit Trees: Everything You Need to Know
In a potted environment, the soil should have a mix of particle sizes. Larger particles (such as pieces of pine bark, for example) provide little pockets of air in the soil. These air pockets allow both water and air to flow freely, which is the key to a healthy root system.
Growing blueberries in containers is a simple solution for gardens with less-than-ideal soil conditions. But if you want to try planting your blueberry bushes in the ground, watch this video for everything you need to know before planting, including variety selection, soil amendments, and planting tips:
DIY Blueberry Potting Mix Recipe
There are tons of blueberry potting mix recipes on the internet. The truth is, I am sure most of them will work just fine! But what I am interested in is a cost-effective, easy-to-make potting mix that uses ingredients that I can source easily.
Here is my recipe for blueberry potting soil:
- 1 part pine bark fines (or aged pine or fir bark/partially composted pine bark)
- 1 part sphagnum peat moss or coconut coir (or use more pine bark)
- 1 part finished compost (homemade or store-bought) or acid/azalea potting mix
- (optional) soil sulfur to acidify
- (optional) coarse perlite to lighten
Pine Bark Fines
Blueberries have been known to grow well in a potting medium of pure pine bark fines (source) and no other ingredients. Pine fines are simply pine bark that has been shredded or cut into small pieces. Sometimes they are aged for a while, which breaks them down partially. The slight advantage to aged pine bark is better water retention (source), but both work well.
Pine bark has a pH between 4.0 and 5.0, has good water retention properties, and allows for easy drainage. This makes it a great substrate (growing medium) ingredient for blueberry bushes.
Pine fines can be tricky to find, however. They are often marketed as “orchid bark” or as bonsai soil. You can use shredded pine mulch, but just pick out the larger pieces. Ideally, the chunks should be less than an inch or two in length.
Peat Moss and Coconut Coir
Peat moss has a very low pH (3.0 – 4.5), which makes it a common amendment for blueberry soils. It also helps with water retention in a soilless potting mix.
However, there is some concern about the environmental impact of harvesting from peatlands. Canadian peat moss may be a more sustainable choice, according to some sources, but there is still a lot of research being done on how to responsibly renew peatlands and keep the environmental impact to a minimum.
Coco coir is a byproduct of the coconut industry and is made from the husk of the coconut. It is generally considered a more renewable resource than peat moss, although some sources debunk this idea. It is also much more neutral in pH, ranging from about 5.5 – 6.8.
For blueberry potting soil, peat moss is a better choice because of the pH range. Both help with water retention and aeration (to some degree). However, since we have other acidic ingredients (like pine bark), coco coir works just fine here.
A note about using both coco coir and sphagnum peat moss – be sure to pre-moisten these ingredients before mixing. Although they both can absorb a large amount of moisture, when they become dry it actually is hydrophobic. Dry coir or peat moss can act like a wick and pull moisture away from the blueberry bushes roots.
Compost
Most compost has a slightly acidic to neutral pH. Compost is a nutrient-rich soil made from fully decomposed organic matter. My favorite compost to use the free kind that I make in my backyard! But any high-quality compost will do.
I like adding finished compost to my blueberry soil because of the nutrient content. Potting soil gets depleted of nutrients very quickly (which is why you need to fertilize often). Any chance to add organic material to fruit tree containers is a good thing.
Another great option for this part of the recipe is any good-quality potting mix that’s specifically for acid-loving plants. The brands listed below are all great options. These mixes are formulated to be at the ideal pH for plants such as rhododendrons, hydrangeas, and – you guessed it – blueberries.
Recommended Store-Bought Potting Mix Brands
Full disclosure – I have not tried all of these, as I use my own blueberry potting recipe above. But I chose each of these to recommend after lots of research. I looked at ingredient quality, soil texture and drainage, pH level, and of course price. These are all products that I would definitely buy to use with my own blueberry plants.
There aren’t very many commercially available potting mixes for blueberries and other acidic plants. You can buy many high quality potting mixes (my favorite is Fox Farm Ocean Forest), but they typically have a pH range between 6.0 and 7.0, which is too high for blueberries. Using an acidic fertilizer isn’t enough to counteract a too-neutral soil pH, so getting the acidity right is key.
Coast of Maine
I like the Coast of Maine Organic Potting Soil for Acid Loving Plants for its high-quality ingredients. This mix is made from compost, peat moss, aged pine bark, and lime to balance the pH to the right level. The soil has a pretty fine texture, so I’d add shredded pine bark to it to improve drainage. The price isn’t bad for a specialized product like this one, and it comes in a 20-quart bag.
Dr. Earth
I love all of Dr. Earth’s products, especially their 5-2-2 fruit tree fertilizer, which I use all the time. The Dr. Earth Acid Lovers Planting Mix organic potting mix contains all sorts of great ingredients, including their proprietary TruBiotic soil microbes plus mycorrhizae, which aids in nutrient absorption and overall plant health. This mix has a pH of 5.5, which is perfect for blueberries. I would probably still add some shredded conifer bark or pine fines to help with drainage.
Perfect Plants
A somewhat pricier, but very appealing, option is this Perfect Plants Blueberry Soil Mix. I love supporting small, family-owned companies like this one. It’s made from mostly aged pine bark and Canadian peat moss, plus some granite sand and other ingredients.
This is the best one I’ve found that looks like it can be used straight out of the bag without adding any amendments for drainage. It does contain a slow-release fertilizer, so keep that in mind when feeding your blueberry plants.
