This article is an introduction to the gardening technique of Backyard Orchard Culture – a system of high density planting of fruit trees which allows for a wide variety of fruit to be grown in a limited space, and harvested over a prolonged period of time.
Typically, most people grow fruit trees the same way that they are grown in large scale agriculture. That is, full sized, and spaced far enough apart to drive a tractor between them…
Now, if we look at a farmer’s requirements, the aim is to get the highest possible yield per tree, for a single variety of fruit, so, for this reason, they will grow many identical full sized fruit trees. The trees will be 15-30 feet high and almost as wide, and will be expected to produce something like 200-300kg of fruit per tree, all at once, over a very short period.
When we consider these facts, we can already see the problems this entails for the urban backyard fruit grower:
- Limited Space – a typical backyard cannot accommodate many full sized fruit trees. You might not even be able to squeeze in a single full sized fruit tree if it is a small backyard, which is fairly common nowadays!
- Limited Variety – if you can manage to squeeze in two full size fruit trees, you only get to eat two types of fruit, no more.
- Overproduction – a regular family will be hard pressed to use a huge amount of one type of fruit, even utilising techniques such as preserving, drying, etc. Not to mention the possibility of getting completely bored with eating so much of the the same thing over and over.
- Very Short Productive Season – basically, it’s a glut, then a famine… All the fruit comes at once, over a few short weeks, and then there is nothing!
- Difficulty in Harvesting – collecting fruit that is sitting 15 or more feet above the ground is not an easy task, even with the right equipment, and is usually more trouble than it is worth.
- Difficulty in Maintaining – spraying a full size tree is a nightmare, and may be physically impossible in the context of a backyard scenario. Pruning a very tall fruit tree is no better, and spreading a net over a fruit tree to protect the fruit from birds is not a viable option when we’re talking about full size fruit trees.
So, how does the technique of Backyard Orchard Culture solve these problems? Simply by using small trees! Yes, seriously! There’s more to it though…
The Benefits of Keeping Fruit Trees Small
By restricting the size of the fruit trees through various methods, to a size of your choosing, and planting them closer together, you gain these benefits:
- Optimum Use of Limited Space – you can literally fit dozens of fruit trees in an average backyard, and a respectable number in the smallest of backyards!
- Wide Variety – this system, on account of the efficient use of space, will allow you to plant a wide variety of fruit trees, so you can eat all different types of fruit from your home garden, rather than just one or two. Having multiple varieties also means that you can have trees which are pollinators for each other, ensuring better pollination and consequently, better yields.
- Sensible Production – the smaller trees will obviously produce much less fruit than full sized trees, but they will produce enough to provide for a family’s needs without wastage.
- Extended Productive Season – since you can plant more trees closer in together, you can have several varieties of the one fruit, that produce over different times in the season. This will give you fruit over a longer period, rather than having one tree producing for only a shorter period.For example, instead of one apricot tree that produces mid season, you can plant three different varieties in the same space, and early, mid and late season bearing apricot tree. This will give you an adequate supply of fruit over an extended period rather than a huge amount all at once. Plus you get a range of different varieties to make it more interesting!
- Ease in Harvesting – you decide how tall the trees grow, many choose to keep them as high as their arm will reach, so you can simply walk past and pick the fruit at your leisure.
- Ease in Maintaining – when the tree is not much taller than you are, tasks like spraying, pruning an netting are fairly straightforward tasks that don’t require any fancy equipment to accomplish.
OK, this all sounds great, but you’re probably wondering, what’s the catch?
At this point I’ll mention my very own Universal Rule of Gardening, which runs as follows:
“The more you want to control the growth of your garden, the more effort it will take to maintain it“
Well, there’s always a cost, and in this case, it’s pruning…
Why Prune to Keep Trees Small When We Can Use Dwarf Trees?
To keep the trees small, it’s your responsibility to train them to the right size and structure when they’re young, and maintain them this way through regular pruning.
You may be thinking, why not just use dwarf trees?
Well, you can, but “dwarf” trees are not necessarily dwarfs at all… Some dwarf trees, such as dwarf citrus trees may only grow to 5 feet high, which is ideal. Many other “dwarf” trees though will grow to 12 feet high, which is not exactly that small. So, even many of the dwarf varieties of fruit trees will need pruning!
The Backyard Orchard Culture technique also make use of espaliered trees (trees grown flat against a wall or trellis) to take advantage of small spaces.
While this may not sound like anything new, the real innovation is the way the trees are planted. I did mention that Backyard Orchard Culture is a high density planting technique, and that is the key. With this system, trees are planted very close together to limit each others growth, as they compete for nutrients and water. The size is maintained with pruning.
How Close Are Trees Planted to Each Other in Backyard Orchard Culture?
The spacing of the trees in backyard orchard culture depends on then pruning style used, how the trees will be trained, and there are various options, such as:
- Two-to-a-hole or many-to-a-hole planting
- Espalier
- Cordon
- Hedgerow
- Compact vase or central leader form
Spacing for Many-to-a-hole Plantings
Trees are typically planted 45cm – 90cm (18″ – 36″) apart, in various arrangements for two-to-a-hole or many-to-a-hole plantings, as shown in the diagram below.
They can be planted two, three, or four into a hole, as espaliers, hedgerows or columnar cordons.
Here are some examples:
Trees can be combined in a many-to-a-hole planting to form a single canopy in a garden bed.
They can also be aggregated together to create a group of many-to-a-hole plantings.
The two-canopy planting shown below is comprised of 8 separate trees, and the one below it, ten.
Trees can be planted in a row using this system of high-density planting to create a hedgerow, screen or fence.
A row planting can also be combined with a long espalier planting to create a corridor between fruiting trees.
Source of planting layout designs: Dave Wilson Nursery, Hickman, CA
High-Density Fruit Tree Planting Considerations
These are examples of techniques used to maximise space when planting trees. You can put two, three or four trees in one hole, as well as espalier trees or grow them as a hedgerow (a long continuous hedge with many stems/trunks).
When planting multiple trees this close together, if you can, make sure they use similar rootstocks (commercially bought fruit trees are grafted onto various rootstock to give the trees specific properties) to ensure that they are equally vigorous and grow at the same rate, otherwise some will grow faster and outgrow their neighbours. If you are planting the trees a few feet apart, this is not an issue.
My personal strategy is to determine how large I wish the tree to grow, make an allowance for a foot or so of space on each side, then calculate the spacing.
In the example below, you can see how 5′ wide trees with a 1′ gap between them will need to be planted 6′ apart.
When planting this way, you have two or more distinct trees clearly visible.
If using the “many in one hole” technique of planting, with the trees 18″ apart, the trees blend into each other to look like one big tree with multiple trunks.
The Four Key Elements of Backyard Orchard Culture
There are four basic principles in Backyard Orchard Culture, and each are equally important to make this system work successfully.
- Trees must be kept to a reasonable size, and it’s our responsibility to keep trees manageable.
- Trees need to be pruned, and we need to understand the reason why we prune trees.
- Trees need to be trained in their first three years to establish a framework of branches and form the shape of the tree.
- Thinning the crop through pruning to produce a consistent crop of quality fruit each and every year.
Let’s look at each of these in turn:
1. Responsibility for Tree Size
The only way to keep your tree to a manageable size is by pruning.
The decision to keep a tree smaller than its full size means you have the responsibility to keep it that way, through pruning, for the life of the tree! Choose the size that you want a tree to be, and make sure you don’t let it get any bigger than that.
A good tree height is one that allows you to pick the fruit while standing on the ground or on a low step-stool.
A helpful hint which will save you a lot of pruning – avoid excessive use of nitrogen fertiliser and excessive irrigation! High nitrogen levels and high water availability can stimulate excessive vegetative growth (shoots and leaves) and reduce fruit quality.
2. Understanding the Reasons for Pruning
Most deciduous fruit trees (trees that lose their leaves in winter) require some sort of pruning.
When a tree is pruned properly, it will produce high quality fruit much earlier, and the tree will live significantly longer.
There are many benefits, pruning a fruit tree:
- Assists newly planted trees to get established.
- Promotes the development of a strong framework of branches on young trees, so they are capable of supporting a good crop.
- Develops and maintains the size and shape of the tree.
- Encourages the growth of new fruiting wood, to keep the tree productive.
- Reduces the incidence disease by removing broken, dead, or diseased branches.
- Creates spacing between branches. This allows air circulation through the tree, which discourages disease development. It also allows light into the centre of the tree, prevent shading and maximising photosynthesis.
- Makes spraying, thinning and harvesting easier.
- Enhances early productivity.
- Increases fruit size and quality.
- Promotes flower bud development throughout the tree canopy.
- Reduces the tendency for biennial bearing.
3. Pruning for the First Three Years to Establish the Tree Framework
Pruning is most important in the first three years of the life of a fruit tree, because this is the time when the shape and size of the tree is established.
It is definitely much easier to prune and train a small tree to a small size than it is to try to prune a large tree down to size (which has to be done in small steps over several seasons, otherwise severe pruning might kill the tree).
In Backyard Orchard Culture, pruning process is fairly straightforward.
Below is an outline of the pruning process as carried out over the first three years:
Pruning to Establish Tree Framework – First Year
Bare-root trees
- Right after planting a new tree, cut off the top so it is only 24 to 30 inches (60-75cm) high to encourage low branching and to equalize the top and root system. It can be cut at 15 inches to force very low scaffold limbs, or higher, up to four feet, depending on existing side limbs and desired tree form.
- Cut any side limbs back by at least two-thirds (or 1 to 2 buds) to promote vigorous new growth.
- After the spring flush of new growth, cut the new growth back by half. (you can distinguish new growth as it will still be green flexible wood and will not have turned woody and hard yet like the previous years growth)
- In late summer, cut the subsequent any new summer growth back by half.
Potted trees
- When selecting potted trees for planting in late spring/early summer, select trees with well-placed low scaffold limbs. These are usually trees that were cut back at planting time to force low growth.
- Cut back new growth by half now, and again in late summer.
Multiple trees in one hole
Two/three/four trees in one hole.
- At planting time, cut back all trees to the same height.
- Cut back new growth by half in spring and late summer as above.
- In the first two years especially, cut back vigorous varieties as often as necessary.
- Do not allow any variety to dominate and shade out the others.
Pruning to Establish Tree Framework – Second Year
Pruning is the same as the first year.
- Cut back new growth by half in spring and again in late summer.
- For some vigorous varieties, pruning three times may be the easiest way to manage the tree: spring, early summer and late summer.
Pruning to Establish Tree Framework – Third Year
- Decide on the height of the tree and don’t let the tree get any taller than that. If there are any vigorous shoots that grow above the chosen height, cut them back or remove them completely.
- Remove any dead or broken branches.
- Remove any diseased branches well below the signs of disease.
- Ensure that the smaller branches that bear the fruit (which will be 1, 2 and 3-years old) have at least six inches (15 cm) of free space all around them. If two branches begin at a point close together and grow in the same direction, one should be removed. When limbs cross one another, one or both should be cut back or removed.
To develop an espalier, fan, or other two-dimensional form, simply remove everything that doesn’t grow flat. Selectively thin and train what’s left to space the fruiting wood.
Many people tend to avoid pruning because they fear they will do it incorrectly. It is important to realise that there are various ways to prune a tree and no two people would do it in the same way. A lot of it is a matter of personal judgement, and ultimately, the best way to learn how to prune by just doing it!
Correct Pruning Technique – How to Remove Branches
When removing branches smaller than your thumb, use a good pair of hand clippers (secateurs) or a hand saw and carefully cut off the branch at its base without damaging the collar.
The branch collar is a distinctive bulge at the base of the branch, where it connects to the trunk. It is actually interlocking layers of cells of the branch and the trunk, and is the part that will heal the wound left by pruning. The branch collar seals off the wound, minimizing disease and decay.
Proper pruning leaves the branch collar intact. Branch collars vary widely from tree to tree, and from species to species. Some are large and very noticeable, while some are much harder to distinguish.
Correct Pruning Technique – How to Saw Off Thick Branches Using the Three-Cut Method
When removing large branches, to prevent tearing off the bark and damaging the tree as it comes off, use a three-cut method of pruning as shown below.
- First, undercut the branch a few inches away from the trunk to prevent bark tearing.
- Next, move a short distance from the first cut farther out on the branch and remove the entire branch. This will eliminate the weight of the branch, so you can make a final pruning cut.
- Start the third pruning cut on the outside edge of the branch-bark ridge and cut through the branch to the outside edge of the collar swelling on the underside of the branch.
Remove only the branch, do not damage the trunk. Don’t cut the branch flush with the trunk or parent limb, be sure to leave a collar (a short stub).
4. Fruit Thinning for Consistent Cropping
Thinning fruit is usually done to prevent fruit drop, broken branches and biennial cropping, and is done at the flowering stage or when the fruit is very small. Thin clusters of fruit, leaving 2 to 3 fruits in each cluster, and space out fruit along the branch 15 to 20 cm apart by pinching out all flowers or fruit in between.
Pruning at the same time as thinning the crop is strongly recommended. By pruning when there is fruit on the tree, you can tell which kind of wood (one year-old wood, two year-old wood, spurs, etc.) the tree sets fruit on, which helps you to make better pruning decisions.
How Summer Pruning Works to Control Tree Size
There are several reasons why summer pruning is the easiest way to keep fruit trees small.
- Pruning reduces the total number of leaves, which are the part of a plant that carry out photosynthesis, (the process by which plants use sunlight, carbon dioxide and water to create their own food). Since days are longer in summer, plants receive more light, so more photosynthesis occurs during this season. Pruning reduced photosynthesis, which reduces the amount of food materials and energy available, which reduces the overall capacity for tree to put out new growth.
- Reducing photosynthesis also reduces the total amount of food materials and energy available to be stored in the root system in late summer and autumn. This controls vigour the following spring, since spring growth is supported primarily by stored foods and energy.
Time-frame for Establishing a Backyard Orchard
One thing that I quickly realised after planting a backyard orchard is that it is not going to yield its produce as fast as annual vegetables do, it really takes time. From the previous instructions on pruning, it is evident that it will take around three years of pruning to train many varieties of tree to form a sturdy and healthy framework of branches to bear the weight of fruit they will carry.
Additionally, trees take years to mature, and the amount of fruit they produce increases as they grow in size and in age. So it is important to be patient with such an endeavour, as you are establishing a natural system that will be productive for decades and possibly longer than a human lifetime.
With that in mind, the sooner you plant your trees, the sooner they will be productive, which is a good reason not to procrastinate and get planting!
References:
- Dave Wilson Nursery, Hickman, CA – Copyright 1994, 1999 Dave Wilson Nursery
- “How to Prune Trees” – NA-FR-01-95, USDA Forest Service, Northeastern Area State and Private Forestry – Peter J. Bedker, Joseph G. O’Brien, and Manfred M. Mielke
- “Pruning Shade Trees” – Kim D. Coder, Extension Forester, Warnell School of Forest Resources, The University of Georgia, College of Agricultural and Environmental Sciences, Cooperative Extension Service
- “Tree Pruning Guide” – Part ISunshine Nursery & Arboretum