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Growing your own fruit tree in your backyard may seem impossible if your soil is of poor quality, does not drain well, or seems to be a haven for weeds. If this is the case for you, a raised bed may be the solution you’re looking for.
Fruit trees can grow extremely well in raised beds because raised bed gardening gives you more control over soil quality, soil drainage, weed infestations, soil compaction, and more! Furthermore, if you’re willing to do a little extra work up front, raised beds are easy to maintain throughout several growing seasons.
Types of Raised Beds
The size and depth of raised beds vary from garden to garden depending on the desired plants, the needs of the gardener, and the available space. However, raised beds typically fall into one of the following categories:
- Raised ground beds. These resemble mounds of soil, often mixed with compost, that measure eight to twelve inches above ground level.
- Supported raised beds. These are constructed right at ground level and also rise about twelve inches high. However, supported raised beds use wood, stone, or other materials to create and support a border around the bed, allowing you to make the bed larger and deeper than a simple mound.
- Containerized raised beds. Often made of wood, these large planters are usually raised well above ground level (source).
Fruit trees do well when planted on raised ground beds; for more information, see our article on Planting Fruit Trees on Mounds: A Complete Guide.
You can also grow some fruit trees, such as dwarf cherries and citrus fruits, in containers. However, the recommended containers for small fruit trees are still much larger and deeper than a typical raised bed that you might use for vegetable gardening.
The remainder of this article will focus on growing fruit trees in supported raised beds.
Benefits of Planting Trees in Raised Beds
Of course, you can successfully grow fruit trees without constructing a raised bed. However, planting in a raised bed is a great way to set yourself up for success. Raised beds offer the following benefits:
- Control over soil quality. This is because you will likely need to buy soil to add to your existing soil in order to fill the bed. This allows you to purchase soil that drains well, has the ideal pH level, is free of diseases and harmful bacteria, and is in good condition.
- Prevention of damage to your tree. It is easy for gardeners to unwittingly damage their trees while mowing their lawns, renovating their homes, or doing other mechanical work. In a supported raised bed, this kind of damage is much less likely to occur.
- Weed control. It is extremely difficult for weeds to infiltrate a raised bed, even a supported raised bed that rests right on the ground. The wooden or stone barriers that support the bed make it nearly impossible for weeds to take over.
Here’s a great YouTube video outlining the benefits of this approach.
Preparing the Site
Improper site selection and preparation is one of the most common reasons fruit trees fail, regardless of whether they were planted directly in the ground or in a raised bed. A fruit tree is a long-term investment, so it is in your best interest to choose and prepare your planting site properly.
Regardless of the type of fruit you wish to grow, your tree’s planting site should include the following:
- Plenty of space. Find out how tall and wide your tree will be at full maturity, and keep in mind that your tree’s root system will extend beyond the width of its branches. Look for a location where your tree’s branches will not touch structures or other trees.
- Abundant sunshine. If you want a good fruit harvest, your tree will need six to eight hours of direct sunlight per day throughout the growing season.
- Some shelter from wind. Some fruit trees rely on wind to aid in pollination; others do not tolerate wind very well at all. Research your desired fruit tree’s wind tolerance and plan accordingly.
- Good airflow. Cold air often settles at the bottoms of slopes, and pockets of warm air often develop near buildings. Neither cold air pockets nor warm air pockets are good for fruit trees.
If there is not a spot in your yard that meets these criteria, consult a local Extension agent or another garden expert. They can advise you of hybrid cultivars, container-friendly dwarf varieties, or other fruit tree variants that may suit your needs.
See our list of the best fruit trees to grow in zone 7b.
Once you choose a planting site, there are two soil tests you should conduct: a general soil test and a percolation test. Even if you plan to buy the best soil on the market for your raised bed, your tree’s roots will still come into contact with the native soil in your yard. Your soil tests can provide you with crucial information as you prepare to plant.
You can purchase a soil test kit from AgriTech that allows you to simply send in your soil sample and get results and recommendations within 48 hours.
General Soil Test
Collect a sample of the soil from your planting site and have it tested by your local Extension Agency or another soil expert. Their analysis can give you the following information:
- Your soil’s composition (i.e., sand or clay)
- Your soil’s pH level (its acidity or alkalinity)
- The nutrients your soil already contains
- Whether or not harmful fungi, bacteria, or other organisms are living in your soil
Use this information to guide you to the right tree, the right type of soil to buy, and the right fertilizers to add. If your soil test shows that harmful organisms are abundant in your planting site, you may need to apply fungicide to your soil or choose a different location for your tree.
A percolation test will tell you how well your native soil drains. The results of your percolation test can help steer you toward the right soil amendments, including which type of soil you might like to purchase to fill in your raised bed.
You can conduct a percolation test very easily by following these steps:
- At your planting location, dig a hole one foot wide and one foot deep.
- Add water to the hole until it is completely full. Allow the water to drain overnight.
- The next day, fill up the hole with water a second time and use a ruler or other gauge to measure the water’s depth.
- Measure the depth every hour until the hole is empty.
The ideal drainage rate is one to three inches per hour. If the water drains from your hole more slowly, you will need to add organic matter, compost, peat moss, or another soil amendment to improve its drainage ability.
If your soil drains more quickly than three inches per hour, you will need to irrigate more often. Fruit trees do well in soil that drains well, but if your soil drains too quickly, your trees can become water-stressed even after heavy rainfall.
See Common Problems With Raised Beds for more information.
Constructing Your Raised Bed
Constructing your raised bed will be the most work-intensive part of this process. The good news is that with proper maintenance, you will only have to do it once!
There is no one-size-fits-all shape or size when it comes to supported raised beds. Most raised beds are rectangular, although you may need to get more creative depending on your available space.
As you plan, bear in mind the shallow and extensive nature of tree roots. You will not need to build a raised bed to contain your tree’s entire root structure; that would simply be impractical. However, you may want a raised bed that has more than just a few feet of width so that your tree’s roots can grow freely while it’s getting established.
Examine your available space, research the fruit tree you want to grow, and use that information to help you measure and map out the area where you want to build your raised bed.
A quick Google search will show you a wide variety of materials that gardeners have used to frame their raised beds. However, not all of these materials are recommended or even safe to use in a garden.
The best framing materials for your raised bed include the following:
- Wood that was pressure-treated with micronized copper azole (CA) or alkaline copper quaternary ammonium (ACQ). Both of these chemical compounds are safe for direct contact with your soil (source).
- Stone or masonry. These are more expensive, but they hold up quite well over time.
- Untreated cedar, cypress, or other hardwood. These will need to be replaced after a few years, but they are good options for gardeners who want to adhere to USDA Organic guidelines.
What Not To Use
Avoid using railroad ties, utility poles, or other recycled woods. Railroad ties and utility poles are covered in creosote, which can’t be stripped off and is highly toxic. The chemicals in creosote, some of which are carcinogenic, will leach into your soil and harm your plants (source).
Likewise, recycled woods are often treated with chemical preservatives that the EPA no longer considers safe for ground contact.
For more information about which materials are best for raised beds, see our article 7 Best Wood Options to Use For Raised Gardens.
Your construction methods will depend mostly on the materials you choose. If you lack the necessary tools or expertise, hire some help.
Whether you frame your raised bed yourself or not, it is important to remember that trees’ roots grow just beneath the ground’s surface, mostly within the top 18 inches of soil (source). As your tree matures, its root system may damage the frame. Anchor your frame sturdily, but be prepared to make repairs or modifications as your tree grows.
Once your frame is secure, add amendments to your native soil, if you haven’t already, and fill the frame with soil. As you fill it, tamp the soil down to eliminate air pockets.
Planting Your Fruit Tree
Late winter or early spring is the best time to plant your fruit tree. Once the ground has thawed, it’s time to dig your hole and plant your tree.
Digging the Hole
There are three important things to keep in mind when you dig the hole for your tree:
- Timing. Don’t dig your hole in advance; wait until you’re ready to plant. Digging in advance puts you at risk of sidewall glazing, which occurs when the walls of a hole become hardened. This prevents proper root development.
- Depth. Measure your tree’s root ball before planting. The hole you dig should be only an inch or two deeper than the length of the root ball. You want your tree’s uppermost roots to be just under the surface once it’s planted.
- Diameter. Your hole’s diameter should be at least double the width of the root ball. Most of the root system’s growth will be lateral, so digging a wide hole will make it easier for you to properly arrange the root system when you plant.
Depth and diameter are extremely important. A hole that is too deep or too narrow won’t allow for proper root growth and cannot be corrected after you plant your tree.
Planting Your Tree
Place your tree into the hole, carefully spreading out its roots as you do. If there isn’t enough room for the roots to spread out naturally without overlapping, remove your tree, make the hole wider, and try again.
Keep a firm hold on your tree so that it stays upright as you refill the hole with soil. Use your feet to tamp down the soil. Be firm enough to eliminate pockets of air without compacting the soil and damaging roots.
Your tree will settle a bit as you fill the hole, but it shouldn’t sink. If you notice it sinking, loosen up the soil, backfill the hole more solidly, and tamp the soil more firmly as you continue planting.
Once your tree is in place, water slowly but deeply. A drip irrigation system or soaker hose will work well in your raised bed. Make sure the root ball gets a good soaking.
You should not fertilize at planting time, and you may not need to fertilize at all for the first year. Get familiar with your tree’s nutrient requirements and make a plan to fertilize regularly once your tree becomes established.
You may wish to add mulch around the base of your tree after planting. Mulch aids in moisture retention and moderates soil temperature. Since raised beds tend to be drier and warmer than the ground itself, mulch can be extremely helpful in maintaining your tree’s health, especially during the hottest months of the year.
Caring for a tree in a supported raised bed will not be much different from caring for a tree planted directly into the ground. You may need to irrigate more often, but other care and maintenance procedures will depend on the tree you plant, your climate, and your soil.
Constructing a supported raised bed for your fruit tree is a great option for growers whose soil is poor quality, who want to avoid potential mechanical damage, or who simply want greater control over variables like weeds and diseases. Building the raised bed is the most challenging part of the process, but a well-built bed will last years and give your tree an excellent chance of success.
You may also be interested in our guide on Creating a Raised Bed Garden for Self-Sufficiency Using Pallets.