After moving to Austin, Texas, I was surprised that trees can grow in this rocky soil. But, I was curious if fruit trees specifically could grow in it, and which ones. Here’s what I found.
Fruit trees can grow in rocky soil since they typically have shallow roots. However, rocky soil often prevents root growth or drains too much water. For best results, grow shallow-rooted fruit trees in mounds of soil. The best fruit trees to plant in rocky soil are fig, olive, apple, almond, and stone fruits.
Hitting rocks when planting your fruit trees can definitely be discouraging, but is rocky soil really that bad for fruit trees?
Before we get into the best ones to grow, make sure you know your hardiness zone! This will help you select the right fruit trees for your site.
1. Fig Trees
Fig trees generally grow best in USDA hardiness zones 7-9, but some specific varieties have different preferences.
Natively, fig trees are from the Mediterranean region and like warm, dry weather including areas such as California and Spain.
Mediterranean soil is known for being dry and shallow, so any plants that grow well in the Mediterranean region likely grow well in rocky soil.
Fig trees have shallow roots, with 90% of the roots found in the first 2′ of soil. Other, deeper roots can reach up to 3′ deep. While many factors contribute to the depth of fig tree roots, the main factors are water, nutrients, and space.
The only issue with fig trees is that they have some of the most invasive roots. Instead of their roots growing deep, they can grow up to 25 feet horizontally and potentially damage structures such as fences or walls.
For more on fig tree roots, check out my recent post Are Fig Tree Roots Invasive?.
Fig trees prefer a balanced fertilizer NPK (nitrogen, phosphorus, and potassium).
While chemical fertilizers are good in the short term, they often have long-term effects such as drying out the soil and decreasing the tree’s pest and disease resistance.
This is why I prefer to use organic fertilizer or 2 inches of compost every 1-2 months.
Not only does compost provide nutrients, but it improves the water retention and beneficial soil life. I also add 4-12 inches of mulch on top of the compost for other bonuses such as reduced evaporation and regulated soil temperature.
If you’d like to see which natural fertilizers I recommend for fig trees (and other fruit trees), check out my recommended fertilizer page. You can also make your own fruit tree fertilizer at home.
2. Olive Trees
Olive trees grow best in USDA hardiness zones 8-11, which are usually subtropical.
For example, here in Austin, TX, we have a subtropical climate with rocky soil and olive trees are quite common (along with pecans and peaches).
However, with a dry climate comes dry soil. Fortunately, olive trees thrive in this dry, rocky soil.
Like fig trees, olive trees prefer a balanced fertilizer NPK. If you use store-bought fertilizer, apply as directed (usually every 3-6 months).
Alternatively, olive trees also do well with compost, manure, and mulch.
3. Apple Trees
Apple trees can grow in rocky soil as they require well-draining soil. As long as their roots can take hold and there’s enough soil for nutrients, apple trees will grow well.
Apple trees grow best in USDA hardiness zones 3-8. As long as temperatures don’t go below -40ºF or above 90ºF, your apple tree will grow well. They also prefer full sun (at least 6+ hours daily).
Because rocky soil can have excess drainage, you’ll likely need to adjust your watering or amend the soil.
The best way to water apple trees is to only water when the top 2-4 inches of soil gets dry. You can do this by pushing a finger into the soil, up to the second knuckle.
The goal is to have soil moisture similar to a wrung-out sponge.
Like most other fruiting plants, apple trees like a balanced fertilizer. To see more about apple tree fertilizer, check out my other post: The Top 3 Fertilizers for Apple Trees (+ Homemade Options).
4. Cherry Trees
Cherry trees grow best in USDA hardiness zones 5-8. As temperate plants, they typically like a cooler climate compared to most other fruit trees. They can live with temperatures down to -40ºF. For example, my girlfriend had tons of cherry trees around her in Michigan.
These trees have extensive root systems and prefer well-draining soil. In poorly draining soil, cherry trees are weaker and are more susceptible to root rot.
This is great news as rocky soil is naturally draining.
Cherry trees should be fed fertilizer once per growing season or compost every 1-2 months. Check out my recommended fertilizer page for more about cherry tree fertilizers.
5. Peaches
Stone fruits such as plums, apricots, and peaches can also grow in rocky soil. These plants are also temperate and do best in hardiness zones 5-9.
Also known as drupes, stone fruits are fleshy fruit that has one seed in the middle. Cherries and olives are also considered stone fruits.
All of these fruit trees grow well in rocky soils because they prefer to have their roots closer to the surface for watering purposes.
Stone fruits also prefer a fertilizer with a balanced NPK or compost. I recommend applying 2 inches of compost every 1-2 months along with 4-12 inches of mulch every 3-6 months.
Don’t forget, even self-pollinating stone fruits benefit from having a second tree as a pollinator.
6. Mulberry Trees
Mulberry trees prefer soil that’s loamy and well-draining but are often found to grow in rocky soil.
Over 90% of mulberry roots are found in the top 2-3 feet of soil. Like most trees, mulberries primarily have a horizontal root structure, so you’ll likely find a larger length of roots compared to depth.
When watering, make sure you’re soaking the soil at least 2 feet deep as 90% of the tree’s roots are found at this depth.
Keep in mind that mulberry trees can be invasive, which is why it’s illegal to grow mulberry trees in some areas.
Mulberry trees are usually self-pollinating and grow best in hardiness zones 5-10.
Use fertilizer with a balanced NPK, or compost or manure. Each brand has different potencies, so follow the instructions on the label for the best results.
7. Almond Trees
Technically not a fruit tree, almond trees are deciduous (losing their leaves in the winter) and grow best in USDA hardiness zones 7-9.
Almond trees are incredibly tolerant of rocky soil and are also drought-tolerant. This help explains why 80% of the world’s supply of almonds is grown in California.
When it comes to fertilizing almond trees, here’s what David Doll, The Almond Doctor, has to say,
“Three to four (or more) applications using a general blend (i.e. 12-12-12 NPK) fertilizer per year will produce a nice result. Using a triple 12, this totals about 8 ounces of actual fertilizer applied per tree. Applications should begin upon leaf out and continue about every 4-6 weeks.”
thealmonddoctor.com
To learn more about which plants to grow alongside almond trees, check out my recent post: 10 Best Companion Plants for Walnuts, Pecans, and Almonds
8. Grapevines
Because grape plants are a vine, they can make use of soil not suited for more rigid trees like citrus or oak.
For example, grapevines have thin roots that are great at finding spaces between rocks or compacted soil. As a result, grapevine roots generally grow horizontally along the ground, and not vertically or deep.
For best results, grow grapes in USDA hardiness zones 4-10 and fertilize with a balanced fertilizer, compost, or manure. Grapevines also do better with companion plants such as planting cover crops between rows of grapevines.
Bonus Fruiting Plants That Grow in Rocky Soil
Many plants can grow in rocky soil as long as they have enough soil to use for water retention and nutrients. The fruit trees mentioned above are particularly good at growing in rocky soil, but here are some other fruiting plants that do well:
- Plums
- Apricots
- Nectarines
- Berry Bushes
- Prickly Pear Cactus
Why Is Rocky Soil Usually Bad for Fruit Trees?
The two main disadvantages fruit trees get from rocky soil:
- The rocks physically block the roots from reaching deeper water and nutrients
- The water drains quicker than other soil types
This also means the fruit trees won’t be anchored well and could blow over with strong winds.
While many fruit trees prefer loamy soil with a pH between 6.0-7.0, they can still grow in rocky soils with the proper techniques.
How to Plant Fruit Trees in Rocky Ground
The best way to plant fruit trees on rocky soil is to add at least a 12-inch layer of dirt, compost, and mulch. This is also called the “no-dig” method. By doing so, you’re providing the fruit trees with a growing medium they can use to effectively root and access nutrients (more on this below).
Let’s take a look at some of the top methods of planting fruit trees in rocky soil, starting with the least effective.
3. Use a Pickaxe
While using a pickaxe is an obvious option, and one that will take a lot of work, it’s still an effective way of breaking up the rocks. However, I wouldn’t recommend this option unless you only have a couple of larger rocks.
2. Use Raised Beds or Containers
Raised beds have been popular for a long time since they can be placed just about on any terrain: hilly, wet, and of course—rocky.
Aside from being able to be planted anywhere, raised beds can help you maintain control over the soil and its drainage.
However, one of the biggest cons to raised beds is their price.
I’ve seen many raised beds that cost hundreds of dollars, and it doesn’t really make sense to me.
I like to use fabric for my containers, but for raised beds, I’m moving to a mound and Hugelkultur approach (more on this next). If you’d like some DIY ideas for raised beds that won’t break the bank, check out this post by apieceofrainbow.com
1. Use the No-Dig Method
No-dig means instead of tilling or digging, you’re using mounds of dirt, mulch, and compost to build the soil up. You can then plant in these mounds, giving your plants plenty of access to valuable soil and nutrients. This works great when combined with tougher soils, such as clay or rocky soils.
Here’s how you can use the no-dig method for your fruit trees when dealing with rocky soil:
- Mix equal parts compost and dirt
- Apply in a 12-inch layer throughout your garden, or just use it in mounds where you’ll be planting your fruit trees
- Plant the fruit sapling in the new dirt
- Apply a 1-2 inch layer of mulch on top of the soil
- Supplement with 1-2 inches of compost every month or two
No-dig is similar to using raised beds, just without the frame.
To keep it even easier, you can combine this method with Hugelkultur, which is using trunks, branches, and leaves first, and then covering them with dirt. Not only do you use less soil, but the nutrients from the plant matter will decompose and provide amazing nutrients and hold moisture well for your fruit trees for years to come!
Hugelkutur can even be used in raised beds.
There’s a reason why the no-dig method has been exploding in popularity recently.
Why No-Dig Is Best for the Soil
Digging and tilling expose the beneficial microbes and fungal layer (called mycelium) in the soil, exposing them to the elements and killing them. This is the fastest way to turn soil into dirt. By not having this beneficial layer in the soil, plant nutrients are limited and soil erosion is greatly increased.
While it may be tempting to fight against nature and force the rocks out of the soil, this does more harm than good (not to mention all the work, time, and cost required).
In Gabe Brown’s book, Dirt to Soil, he learned firsthand why conventional farming didn’t work on his ~1000 acres in North Dakota. And one of his biggest lessons learned? Digging and tilling.
In summary, digging and tilling kill the beneficial life in the soil. This is the same soil life that provides valuable nutrients found deeper in the soil in exchange for sugar given from the tree’s roots.
Unfortunately, tilling is also the primary reason why so much topsoil is lost from farms.
As Gabe mentioned in his book, no-dig is what nature does, well—naturally. Think about it, have you seen anything in nature that flips and tills the soil as we do?
So, don’t dig in rocky soil. Instead, grow the soil upwards. You’ll save yourself a lot of time and effort.
By doing so, you’re also providing your fruit trees (and other plants) with amazing nutrition and health, meaning—more fruit for you!
If you’re looking at ways to further improve your garden’s health and productivity, I highly recommend Dirt to Soil (it’s also on Audible).
Final Thoughts
It might seem that you’re stuck with rocky soil, but know that instead of digging down, you can build the soil up.
Most of the time, it’s too difficult to clear rocky soil. Instead, consider using raised beds or the “no-dig” method to provide your fruit trees with soil that they can work with. With this, their roots will find their way around the remaining rocks and take the path of least resistance.
As you add more soil to the mounds, the rocks will become more scarce and gardening will be easier.
While rocky soils can be a downer, many gardeners said they prefer rocky soil to clay soil as it’s easier to amend, so keep that in mind!
If you’re not a fan of any of the solutions above, know that you can still grow your fruit trees in containers or primarily use berry bushes (since their roots are especially shallow).
Remember—you don’t need to buy a lot of soil. There are ways you can get fill dirt for cheap or even free! You can also use any spare logs or prunings in Hugelkultur beds.
If you’d like to learn more about Hugelkultur, and see what happens to logs when they’re buried in raised beds, check out this awesome video by Self Sufficient Me:
