Part 6: Growing Dwarf Fruit Trees in Your Mini Fruit Garden
You can use a variety of methods to grow dwarf fruit trees in your miniature fruit garden – including using genetic dwarfs and mini-dwarf rootstocks; pruning trees as single cordons, fans, and espaliers; and using multi-plantings.
The majority of fruit trees sold by nurseries today are semi-dwarfs. Most people see the word “dwarf” in semi-dwarf and believe these trees will remain small. However, most semi-dwarf trees can grow 10-15 feet high!
Even dwarf fruit trees usually grow 8-10 feet high. I don’t know about you, but that is beyond what I can reach without using a ladder. I prefer to make my trees easy to manage by keeping them 4 – 6½ feet high. I consider it a huge advantage to be able to work on my trees while standing on the ground.
There are a few genetic dwarf fruit trees available that will remain under 8 feet tall, but not many. Genetic dwarf trees remain naturally small with little pruning needed. But it can be difficult to find one that 1) is suitable for both your soil and climate, 2) will resist common diseases in your area, and 3) has a flavor that you enjoy. But if you can find one with the qualities you are looking for, it will greatly reduce the amount of pruning you would normally have to do to maintain a miniature fruit garden.
There are only a few rootstocks that will dwarf a fruit tree to 6 feet high or less without a lot of pruning. One of them is the M27 for apples. This rootstock is also suitable for container growing. The M27 has a very weak root system – which is why it keeps apple trees so small. You need to keep this tree attached to a supporting post or trellis for its entire life, but you can start harvesting a good amount of fruit by its third year. It also needs regular fertilizing and watering, and it is very susceptible to fire blight.
Don’t let a fruit tree with this type of rootstock set any fruit until the tree has grown to the size and shape that you want. This rootstock can’t provide enough energy for a tree to grow its main primary branches and produce apples at the same time. It broke my heart, but I used scissors to cut off every blossom on my mini-dwarf apple trees for the first two years.
I started with apple trees on the M27 rootstock before I found out about the susceptibility to fire blight. I enjoy these mini trees very much, but I expect to lose them at some point to this disease. So I also planted 3 apple trees on fire blight-resistant semi-dwarf Geneva rootstocks. I am growing these trees as espaliers on trellises 5 feet high and 8 feet wide. You might not have a serious fire blight issue, so M27 rootstocks may be a good option for you.
Pruning Fruit Trees as Espaliers and Fans
An espalier is a tree grown on a flat plane, supported by a trellis or sturdy wires. They are placed in front of a wall or fence, along a property line or walkway, or used to create “walls” to divide your garden into different sections.
You can choose from among a variety of formal or casual styles. You can prune espaliers to be an expression of “art work” in your garden, or just a very simple, practical way to grow fruit along a narrow strip. The more casual styles, such as the “fan,” are generally easier to maintain and can be very productive. For a quick review of training a fan, see: How to train fruit trees as fans and espaliers
For apple espaliers and fans, just be sure to choose a “spur bearing” variety of apple, not a “tip bearing” (ask the nursery). Also, if you plan to grow a good-size espalier tree (trellised perhaps 5 feet high and 8 feet wide), then using a more vigorous semi-dwarf rootstock would be a good idea, as the very dwarfing rootstocks won’t support a larger espalier tree.
Cherries are not suited to formal espalier styles, and do best as a casual fan shape or in a multi-planting. Some types of fruit produce best when grown in a small bush form, and not as an espalier.
The American Horticultural Society Pruning and Training book goes into great detail on which styles of training are best for different types of fruit. Whichever method you use, please don’t “clean up” the branches by cutting off the short stubby ringed buds – these are the spurs that will flower and produce your fruit.
Pruning Fruit Trees as Single Cordons
I chose to grow my mini-dwarf apple trees as single cordons – a single trunk with short fruiting branches growing along its length. It’s a very simple form to create. I planted these trees at an angle on a trellis. Growing these single cordons at an angle will slow the growth of the trees and encourage them to produce more fruit, but it does take up a little more space.
Mini-dwarf apple trees can also be grown as small single trees that are kept about 4 feet high and wide. Check out Gene’s Backyard Orchard for photos and directions about this growing method.
At the risk of becoming repetitious, I highly recommend the book, American Horticultural Society Pruning and Training. It includes hundreds of photos and drawings that clearly explain the various options available to you and exactly how to prune and train your plants over the years, from the day you plant them until they become mature. You can also learn more about pruning by viewing the How To Prune a Fruit Tree YouTube videos at Dave Wilson Nursery’s Fruit Tube™.
But you don’t need to use trellises or do a lot of fancy pruning to grow dwarf fruit trees. Probably the simplest method is to grow your fruit trees in closely spaced clusters by planting two to four fruit trees close together, about 18-24” apart. The competition will help to stunt their growth and reduce the amount of pruning necessary to keep them small.
You will still need to prune them 2-3 times during the growing season, to shape the trees and reduce their height, but you won’t have to worry about making the trees fit a particular formal shape. You also won’t have the cost of the trellis. You will, however, usually need to allow this group of trees an area at least 8 feet across.
Plant related fruit trees together, such as several varieties of apples. To extend your harvest, you can choose early, mid-season, and late maturing varieties. Some could be good for fresh eating, and others for storage.
Another factor to consider when choosing which varieties to plant together is their vigor. Some varieties will grow faster than others, and can overwhelm less vigorous trees in their group. Unfortunately, plant descriptions often don’t describe a tree’s vigor very well. Pay close attention if one variety is described as “vigorous” and the catalog doesn’t mention vigor at all for another one. At the very least, choose a similar rootstock for trees that are growing close together. Don’t try growing a mini-dwarf tree together with semi-dwarfs or standards.
When in doubt, plant the variety that may be more vigorous on the north side of the group, so that tree won’t shade the smaller ones. After a few years experience in growing both vigorous and non-vigorous varieties, I now generally prefer to grow the less vigorous varieties, as they take less work to keep small. However, if a vigorous variety is the only one that is resistant to a common disease, I wouldn’t hesitate to grow it.
I don’t have much experience with growing trees or shrubs in containers. However, when I had to move in 2010, I had 300 plants from my garden potted up and moved with me – including 2-year-old fruit trees and blueberry bushes. They handled the transition just fine, even after spending all summer in makeshift containers before I replanted them into new beds. I even harvested a few ripe blueberries while the bushes were still in the pots.
In general, though, I believe that it would be easier on both you and your fruit trees if you planted them in the ground, when it is possible. Trees in containers need more maintenance, and will produce less fruit. However, if you are not able to plant in the ground, or you have disabilities that would make it difficult for you to work in a yard, then containers would be a good option to try. The best book I've found so far on growing fruit in containers is McGee & Stuckey's Bountiful Container: Create Container Gardens of Vegetables, Herbs, Fruits, and Edible Flowers.
If you choose to grow fruit trees or small fruit in containers, I suggest that you try using a fabric pot. Containers made from heavy fabric were originally developed and used by commercial tree growers. There are several different brands available.
- The entire container “breathes”
- They drain very well
- Fabric pots do not overheat in summer sunlight as much as plastic pots – overheating can kill roots and stunt the growth of the plant
- The roots of the plants are naturally air-pruned – this air-pruning encourages the development of a very healthy fibrous root system, unlike the masses of circling roots you often find in plastic pots.
I have used a brand of fabric pot called Smart Pots for three years now in my unheated hoop house. I have grown vegetables in these containers twelve months a year. I have been very satisfied with how vigorous the plants have grown, and how well the pots are holding up. Smart Pots are available in sizes ranging from 1 gallon up to 400 gallons.
One of the disadvantages to growing trees and shrubs in containers in cold climates is the increased risk of freeze damage to their root systems in winter. Because the roots of container trees are not protected by warmth of the ground, the plants “feel” as though they are living in a colder climate – about 2 zones colder. If you plan to leave your container plants unprotected outside all winter, make sure you choose the most hardy rootstock available. Of course, if you live in a place like Florida or California, you don’t have to worry about this.
Some people will bring their pots into an unheated garage or hoop house for the winter, or surround the outdoor pots with mulch to give some insulation. I have often overwintered smaller (1 quart to 2 gallon) containers outdoors by burying the pots in mulch, though it can put the plants at higher risk from damage from mice and voles.
Don’t forget that all containers can dry out in winter, too. Keep the surfaces mulched, check the soil moisture when it isn’t frozen, and water the containers when needed. Also, be aware of the weight of filled containers. A 10-gallon container can weigh 40-50 pounds; a 20-gallon container may weigh 100 pounds!
You can successfully grow fruit trees in a wide variety of small spaces by selecting dwarf varieties, or by using one of many different pruning and training methods. I actually use several different techniques in my own garden, as different methods will work better with different types of fruit. You can find training methods that will let you grow fruit in an incredible variety of small spaces!
Sources for more information
Introduction: How to Grow Fruit (Even If You Have a Tiny Yard)
Part 1: Eight Reasons Why You Should Grow a Miniature Fruit Garden
Part 2: How To Design Your Own Miniature Fruit Garden
Part 3: How to Select Fruit Varieties That Will Thrive in Your Garden
Part 4: Six Steps to Planting a Successful Fruit Garden
Part 5: Growing Berries and Grapes in Your Mini Fruit Garden
Part 6: Growing Dwarf Fruit Trees in Your Mini Fruit Garden