11 Trees For Acid Soils (That Will Thrive)

Maybe I should say acid-tolerating trees, because while some trees really are happiest in acidic soils, others will tolerate them.

Either way, if you have acidic soil in your yard or garden and still want to plant some beautiful trees, read on to learn about a selection of trees for acidic soils, and even a few acid loving trees.

11 Trees that Grow Well in Acidic Soil

1. Acers (Japanese Maples)

Acer Palmatum or Japanese Maple tree
Photo by Tatters at Flickr

While acer (Acer spp.) refers to all trees in the maple group, I’m talking specifically here about those native to Japan and China. While not all acers need acidic soil, many of them prefer it and are happiest when the pH is a little lower.

These beautiful trees tend not to grow to more than 12 meters (39 feet) in height, and some of the weeping varieties may only grow to 4-8 meters (13-26 feet).

Available in a wide range of species and cultivars, acers are deciduous and have beautiful leaves ranging in color from bright green to deep, burgundy red. They’re renowned for their stunningly beautiful autumn foliage. Due to their native habitats, acers tend not to like extreme, prolonged heat or extreme cold.

Depending on the specific species and variety though, there is a bit of leeway. I’ve had an acer in Wales survive a winter when we had 3 weeks where the temperature never rose above -18°C (-0.4°F), and I have a potted one now that has lived happily through 40°C+ (104°F) summers in Spain, Portugal, and France.

If ever you find yourself in Gloucestershire in the UK, I highly recommend a visit to Westonbirt Arboretum. Their collection of Japanese acers (incidentally, growing quite happily in soil with a pH that is not desperately acidic) is absolutely wonderful.

2. Beech

Not everyone has the space to plant a beech tree. In fact, most of us do not! Still, beeches (Fagus spp., the common beech is Fagus sylvatica) are beautiful trees for acidic soils if you can accommodate them.

Growing to a height of 40 meters (131 feet) or more, the beech tree is deciduous with beautiful, oval, green leaves: the bright green of spring at first maturing to a darker, richer color. In autumn, the leaves turn a coppery brown and are preceded in late summer by beechmast, or beech nuts.

They’re tiny, but very tasty. (Don’t forget to save some for the birds and furry creatures though!)

3. Magnolia

The Acidic Soil Loving Pink Magnolia Tree
Photo by Muffet at Flickr

Most — but not all — magnolias (Magnolia spp.) prefer soil that is acid to neutral. They can be evergreen or deciduous depending on the species, and come in a variety of sizes from smaller shrubs to larger trees. They make up around 240 different species and are native to the Americas, East Asia, and the Himalayas.

Magnolias are sensitive to frost and strong winds, and care must be taken to ensure that their soil doesn’t dry out during the hotter months. But if you’re as taken by them as I am, do some research and find a magnolia that suits your situation and soil type.

To look out and see magnolia flowers in early spring truly is a gift from nature.

4. Pine

Most species of pine (Pinus spp.) grow quite happily in acid soils. While there are a few that don’t, the majority don’t mind a lower soil pH and can be found growing in sandy soils, which are often acidic.

In fact, many species of pine don’t really mind where they grow, as long as they have sunshine and good drainage. So no shady clay sites!

There are about 120 different species of pine tree in the world, and all but one them are native to the Northern Hemisphere. Many pines will make the soil around them more acidic via their dropped needles, so do bear that in mind if you want to plant pine and something beneath it.

In fact, it’s worth noting that many broadleaved trees (oak, beech, etc.) will also make the soil around them acidic, although perhaps not as acidic as that around pine trees.

It’s for that reason that woodland soils tend to be more acid than alkaline.

5. Sweet Gum

Sweet Gum Tree or Liquidambar Styraciflua
Photo by Jorge Franganillo on Flickr

Native to eastern North America and the tropical mountains of Mexico and Central America, the sweet gum (Liquidambar styraciflua) can grow to a height of 19 meters (65 feet). A deciduous tree, it has star-shaped, five-pointed leaves that are glossy green in summer and a range of glorious reds, oranges, and purples in autumn.

The sweet gum gets its name from the thick sap that it produces, which has been used in a wide variety of products from chewing gum to poultices.

You might wonder why poultices, but the sweet gum’s resin has medicinal benefits as an anti-fungal and natural pesticide and is currently being studied for its ability to combat drug-resistant bacteria and treat hypertension (high blood pressure).

It’s also worth mentioning that the immature seeds of the sweet gum tree have a high concentration of shikimic acid, which is a primary ingredient in Tamiflu. I know I’ve said it before, but I can’t say it enough: trees and nature are so, so important to the planet’s survival and to ours as well.

6. Pin Oak

The pin oak (Quercus palustris) is one oak that specifically prefers acid soils, in particular those that are rich, moist, and well-drained. Its natural habitat is in the United States east of the Mississippi River, and unlike many other oak trees, it takes on a pyramidal shape as it grows.

Growing to between 15-21 meters (50-70 feet) tall, or even to 30.5 meters (100 feet) or more if the conditions are just right, the pin oak has dark green, glossy, and deeply-lobed leaves. It is a deciduous oak, but may retain some leaves into the winter months.

7. Birch

Birch trees (Betula spp.), like beech and oak to an extent, prefer their soil to be more on the acidic side. As they are related to oak and beech, perhaps this isn’t surprising! A group of around 60 different species, birch trees are deciduous and native to a wide range of cooler areas in the Northern Hemisphere.

Depending on the species, they can grow as larger trees reaching heights of 30 meters (90 feet) or tiny shrubs no taller than 30cm (12 inches). Of course, not all species can live in all habitats and climate zones, but you might be able to find one for you.

8. Strawberry Tree

Strawberry Tree or Arbutus Unedo
Photo by Aries Tottle at Flicker

Contrary to its common name, the strawberry tree (Arbutus unedo) doesn’t grow strawberries. But that’s ok, because it is a beautiful and unusual tree that’s well worth considering if it’s right for your area.

Native to western Europe, from the south-west of Ireland right down through Portugal and into the Mediterranean, the strawberry tree can grow as a large bush or small tree.

Either way, it probably won’t grow taller than about 10 meters (32 feet) and may be considerably smaller.

The strawberry tree is evergreen, with oval-shaped, dark green leaves. It has beautiful, white and fragrant bell-shaped flowers and bears fascinating fruits which ripen over the course of a year from pale yellow-green to a cheerful, bright red-orange.

They’re amazing actually, orange balls covered in bright reddish-pink points when they’re still ripening. I had no idea what it was the first time I saw one, but I loved it!

9. Holly

Further confirming the fact that many woodlands have acidic soil, holly is the next tree on our list. Actually a genus made up of around 400 different species, holly (Ilex spp.) can be found around the world in tropical, subtropical, and temperate regions.

It comes in such a wide variety of colors and sizes that I won’t even try to describe them all here, but the leaves can be green or gold, solid color or variegated. They can even look blue in some cases. Berries can range in color from red to orange, yellow to white, and they can even be black.

10. Monkey Puzzle

Monkey Puzzle Tree
Photo by Hannipic on Flickr

I hesitated in including this one because the monkey puzzle tree (Araucaria araucana) is only native to a small portion of the Southern Hemisphere: western Argentina and central and southern Chile.

However, it’s been grown in various other locations around the world for hundreds of years, and as it generally isn’t considered invasive (although always check for your particular area) and has been around for 200 million years, I figured it deserved a place here.

The monkey puzzle tree can grow up to a height of 30 meters (98 feet) and is evergreen. Its leaves are its most distinctive feature: spiky, stiff, and very green, with a leathery texture and a triangle shape. They’re small and quite sharp and are arranged in spirals around the tree’s branches.

While the monkey puzzle tree doesn’t need an acid soil, it doesn’t mind one either. It does, however, need a well-drained soil whatever the pH. Unlike most of the trees on this list, the monkey puzzle tree is usually dioecious, which means that it has male and female flowers on separate trees.

The tree got its common name in the mid-1800s thanks to the barrister Charles Austin. (In the UK, barristers are lawyers who argue cases in court, solicitors are lawyers who work on legal matters but do not appear before judges).

When he saw the tree for the first time, Mr. Austin observed that climbing it, with its sharp, spirally, and spiky leaves, would be a puzzle even for a monkey.

11. Apple (honorable mention)

Flowers on the Wild Crab or Malus Sylvestris
Photo by Peter O’Connor at Flickr

Yes, apple! Apple trees (Malus spp.), while they can’t handle extremely acidic soils, are happy with a pH of 5.5(ish) – 6.0 and above, maybe even slightly lower depending on the cultivar and overall growing conditions.

Because apple trees are grown as grafts, that is, a living branch of one tree is joined with the rootstock of another, it could seem a bit tricky to work out which tree in particular is best for your situation, especially when you consider that there are literally thousands of different apple cultivars: over 6000 in fact.

However, there aren’t that many different rootstocks, so it’s easier than you might think.

Eating apples aside, crab apples (Malus sylvestris) are apparently the best suited to more acid soil types. So if you don’t mind not eating your apples raw and you’re happy cook them, use them for jelly, or just leave them to the many species of wildlife who love them, consider a crab apple tree.

Native to Europe, they’re lovely specimens, wonderful in the landscape and they bring a touch of wild beauty to any yard or garden. Crab apple trees grow to about 10 meters (33 feet) in height and have delicate, pinkish-white and sweet-scented blossom in spring.

The bees adore it!

Soil pH & Why it is Important

Testing your soil pH levels
Photo by Backyard Boss at Flickr

All soil has a pH value. A scientific abbreviation of “potential of hydrogen”, pH is a measure of acidity or alkalinity. Specifically, it’s a measure of the concentration of hydrogen ions in the soil. A high number of hydrogen ions leads to acidity (and a low pH) and a low number of hydrogen ions leads to alkalinity (and a high pH). 

pH is usually measured by adding a soil sample to a quantity of water. (Water tends to be of a neutral pH — 7.0. — although it can vary.) The resulting pH value indicates how much the soil changed the pH of the water.

The pH of soil will determine the availability of essential nutrients to plants. Depending on the soil’s pH, some nutrients and minerals become more available, even to the point of toxicity, and other nutrients become less available, possibly to the point of plants suffering deficiencies. pH can also interfere with microbial activity.

If you’re concerned that your soil is very acid or very alkaline, or you’d just like to know where you stand, you can buy a DIY test kit from most garden centers / nurseries or even hardware stores. While the kit will give you a reasonably accurate response, you could also send a soil sample to a specialist laboratory for a more detailed and thorough report.

The other benefit of a lab test is that it will also detect the presence of free calcium carbonate (i.e., chalk or limestone) in the soil which DIY tests often don’t. But if you don’t want to pay for professional testing, there is a quick hack that you could try at home: adding vinegar to a sample of your soil. If it fizzes, you’ve got free calcium carbonate.

(And by free, I don’t mean that it doesn’t cost anything. Although if it’s in your garden, it’s probably that sort of free too. What free means in this case is unbound. The calcium carbonate is freely available and not bound to any other mineral or substance.)

Very Acid

If your soil pH is between 3.0 and 5.0, your soil is very acid. Too acid at the lower end: even most trees that are happy in acidic conditions aren’t overly happy below pH 4.5.

In this case, you could consider adding lime (i.e., calcium oxide or similar, not a citrus fruit) or a liming agent to the soil to raise its pH and alkalinity temporarily. However, I would strongly suggest that you consult an expert in soil chemistry to help you get the dosing right.

Slight Less Very Acid

At a pH of 5.1 – 6.0, your soil is acid, but not terribly so. Ericaceous (or lime-hating) plants will do well, and you’ll be able to plant acid-loving (or acid-tolerant) trees. However, you would need to add lime to plant anything that prefers more alkaline soil.

Moderately Acid

pH 6.1 – 7.0 is classed as moderately acid, but reasonable for growing most types of plants apart from those that really need acidic conditions. This, and perhaps up to 7.5, is considered to the best pH range for most gardening and growing and is around the optimum range for nutrient availability (often stated as 6.5 – 7.5).

Neutral

7.0 is considered a neutral pH, neither acid nor alkaline. This is the pH of pure water. Once you move up past that, you get into the alkaline range.

Alkaline

Soil with a pH of 7.1 – 8.0 is considered alkaline (as would anything higher), and may cause problems for a wide variety of garden plants. However, apparently a slightly alkaline soil pH can reduce the incidence of clubroot disease in brassicas (plants in the cabbage family, including broccoli and kale), so every cloud has a silver lining!

Overall

In the UK, for example, most soil is of a neutral pH or slightly acid. The overall range is about 4.5 – 8.0. Where alkaline soils are found, they tend to be in areas on bedrock of chalk or limestone: lots of free calcium carbonate.

As always though, bear in mind your location, climate, and situation. Try to to find a tree that’s native to your area, and if you’re going for non-native, make absolutely sure that it isn’t considered invasive where you are.

If You Have Acid Soil

If you have acid soil, find out the specific pH, and then do some research to determine the best trees for your soil, situation, and place in the world. If you’re in doubt, it’s always best to consult a qualified arborist for advice.

Whatever tree you choose, enjoy it and enjoy getting closer to nature.  You might just feel better for it!

Featured Image by Smudge 9000 on Flickr

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