Smaller urban gardens can be restricting to an avid gardener. As a result, more needs to be spent planning to make the most of a more compact space. Years ago, many folks wouldn’t even contemplate the idea of planting and cultivating a fruit garden in any area short of an acre in lush green grassland. This is where columnar apple trees come in.
Nowadays, however, we have so many more fruit tree and rootstock options that even a small urban garden can be an attractive, highly productive plot of land. The key to success when planning and planting up compact outside areas is to choose your plants well. Pick cultivars that won’t outgrow their space, and will bring something special to the garden.
Today I’m touching on just that subject: columnar apple trees for compact urban spaces. I’m pleased to say that times have changed as far as fruit gardening goes. The need for dwarfing apple trees that grow vertically, rather than horizontally has well and truly been met. Now, everybody can grow their own fruits in their own backyards.
These precious, productive trees are known as Supercolumn or Vertical Cordon Fruit Trees. This includes the new Ballerina and Minarette varieties.
Firstly, lets take a look at the choices of fruit trees suitable for the smaller urban garden which please the gardener, help to create a mini ecosystem and attract a wealth of wildlife.
What Exactly as a Columnar Apple Tree?
Well, it’s actually a vertical cordon tree that should have a mature height of no more than 2.4m/8 feet tall. Its lateral fruiting branches are pruned in the summer months to keep it restricted in shape. The idea is that the fruits are produced on the vertical stem, rather than the lateral branches.
Why Choose a Columnar Apple Tree?
The beauty of vertical cordon fruit trees is that their slim structure allows you to plant them closer together. This allows gardeners to plant a wide choice of fruit cultivars in a relatively small amount of space. Unlike traditionally shaped fruit trees, columnar apple trees can be spaced as closely as 2–3 feet apart.
You’ll find that many nurseries now sell “mini-orchard collections”, specifically for compact gardens. These usually include pear and apple trees, along with plum and cherry, although stone fruits have proven to be less successful when grown in the vertical form. The necessary regular pruning makes them more susceptible to fungal infections.
How do I choose the right tree?
Let’s quickly explain the different columnar apple trees, helping you to make the right choice for your space.
The Ballerina Group
These trees have a natural columnar shape, rather than a manipulated one. There are several varieties available, all growing with a single pole stem and very short, almost non-existent side branches. Ballerina Apple trees have the tightest-growing form of all the choices available, and descend from a common ancestor apple: the McIntosh Wijcik. This, incidentally, is a relative of the well-known McIntosh apple cultivar.
Ballerinas are compact, ornamental trees, perfect for smaller gardens. In addition, they require less hard summer pruning than other similar forms. A disadvantage to this group is that the naturally growing variety of apple cultivars is quite limited, and regarded as less flavoursome. That said, there are new variations becoming available all the time.
Minarette and Supercoloumn Apple Trees
Both of these are regular apple trees that have been manipulated by close-pruning. This concentrates fruiting along the tree’s main stem to achieve the popular columnar effect. They’re not a specific apple variety—just a style of training and pruning. These are also known as “Vertical Cordons”.
Many apple and pear trees can be trained in this vertical growing manner, which has many advantages. It brings far more variety to the buyer, better, flavoursome fruits, and ultimately, higher yields than cultivars in the Ballerina group. Minarettes produce an abundant crop of fruits on short spurs all the way up the vertical stem, reaching a manageable height of 6–8 feet in maturity.
Maintain regular summer pruning with the Minarette and Supercolumn trees, or they’ll revert back to their natural forms.
What are Oblique Cordon Fruit Trees?
Many fruit-growing fanatics will already have heard of “oblique cordon” trees. These are fruit trees that have been pruned in the same way as above, but planted in the ground at a 45 degree angle. Oblique cordons are generally seen to be a more productive method of fruit cultivation.
This is because the stem’s angle successfully mimics the branch angle on a regular fruit tree. hese results confirm the general principle of fruit trees, being that horizontal growth provides fruit, while vertical growth is greener and more vegetative.
Overall, all fruits grown in any of the cordon forms are shown to be of a good quality. Sunlight penetrates every part of the tree which aids in the all-important ripening process.
Which sort of Cultivars are Best for Growing as a Columnar Apple Tree?
Cordon training is a useful way of growing a good amount of great-quality fruit in even the smallest spaces. It’s a suitable growing technique for all apple and pear cultivars that bear their fruits on short side-shoots. These are also known as spur-bearing fruit trees.
In addition to cultivars that are tip-bearing (bear their fruits on the tips of the branches), very vigorous cultivars are best avoided when choosing to grow as columnar trees. These can be difficult to keep in shape, and pruning would remove the tree’s fruiting parts.
Partial tip-bearing cultivars, (apples that bear their fruits on both tips and side-shoots), can be grown as cordons. Just leave some short branches unpruned each year to achieve successful cropping.
It’s worth looking into the different rootstocks that are available. The rootstock of your tree will depend on its overall mature growth height, and growth speed.
The best rootstocks for Columnar growing apple trees are as follows:
- M27 – Extremely dwarfing
- M9 – Very dwarfing
- M26 – Dwarfing
If your soil is nice and fertile, choose the M27 or M9 rootstocks. These will be of sufficient height and growth rate to produce a good specimen tree for the smaller garden. The M26 rootstock would be your best bet for less fertile soils. These are slightly bigger, and are more vigorous growers.
Using a smaller rootstock is always better than choosing one that’s too vigorous for your needs and space. Water, feed, and mulching will all help to improve your tree’s vigour, giving it a boost if needed. It’s not quite so easy, however, to reduce your trees’ overall size and growth rate.
Some of the best ballerina cultivars are listed below, along with their fruiting details and cropping times.
- Flamenco: A great dessert apple descended from the renowned Cox cultivar. Dark red fruits are ripe by Mid October, with a crisp texture and slightly acidic taste. Apples store well.
- Samba: A relatively new variety that produces crisp, tasty, red-skinned dessert fruits in October.
- Bolero: An early-fruiting variety that produces golden-flushed green fruits from mid September.
- Charlotte: A cooking variety with very large green and red blushed fruits. Crops late Sept–October, and its fruits store well.
- Polka: Another good dessert apple that crops from late September. It creates bright red fruits with a good flavor.
- Waltz: Dessert apple with red and green fruits, which crop in October. Very sweet with good flavor.
Minarette and Supercolumn Trees
This intensive, relatively modern growing system creates a heavy crop-bearing, seven-foot-tall tree with fruits produced on the full length of the stem. Cultivars are generally grafted onto Super Dwarfing Rootstock–M27, and these are grown as free-standing trees, supported by stakes.
There is a vast selection of apple cultivars to choose from, including favourites such as Granny Smiths, Lord and Lady Lambourne, Egremont Russet and the renowned Christmas Pearmain. It’s really a matter of personal choice.
Now that we’ve dealt with the perfect trees, lets talk about perfect planting sites.
Planting your Columnar Apple Trees
When to Plant
Plant your trees from late winter to early spring, using one-, two-, or three-year-old trees.
Your planting site is just as important as your choice of tree. Try to choose a bright and open position, sheltered from strong winds and frost pockets.
After planting your columnar apple trees, cut back any long side-shoots to three buds from the main pole stem, leaving the leader and any shorter side-shoots unpruned.
Your soil needs to be fertile, free-draining and non-waterlogging. Clay soils can be a pain, but this can be overcome by digging a large planting hole and incorporating soil improvers into the mix.
Pot-grown Fruit Trees
If you have limited spaces of open ground, your columnar fruit trees can be planted individually in large pots—at least 18 inches wide. Here they’ll grow quite happily in a rich, well-draining compost, as long as they’re fed throughout the growing season and kept sufficiently watered.
As previously mentioned, one of the benefits of growing columnar apple trees is they can be grown in very small areas. When planting more than one tree, spacings of two to three feet would be ideal.
Staking your Trees
All newly planted trees need some support to ensure they grow strong and upright, with their roots firmly in the ground. Each of your columnar apple trees will need the support of a tree stake and tie. As a result, they should have plenty of growing support and stability until they’ve properly rooted in the ground. Tree stakes should be around 8 feet tall, with two feet below the ground and the remaining six above.
When planting your favourite apple cultivars, choose a suitable pollination partner to ensure cross-pollination. This is the transfer of pollen from one variety to a different variety of the same tree, and is essential for successful fruiting. There are many examples of compatible tree charts online that you can refer to.
Caring for your Columnar Apple Trees
Once planted, water your trees well and leave them to settle in. I recommend watering them regularly for the first three weeks; around every three to four days if the weather is dry. Then give them a good drink once a week and remember to keep the base of the tree weed-free.
Mulching is a good way to keep moisture in your planting site’s soil, especially throughout dry periods and in winter time. I always mulch newly planted trees with a bulky homemade compost, then again in the autumn. Ideally, spring and autumn are the best times to mulch each year which not only conserve moisture, but will also reduce weed growth.
It’s always important to feed your plants during the growing stage, as doing so will keep the plants strong and healthy. Fruit trees especially need good nutrition to aid in producing a super harvest.
I recommend using a very well-diluted fruit fertilizer for very young, non-productive trees until they become more established. Initially, it’s important for the root systems to strengthen, so more phosphorus and potassium is needed in the fertilizer, but less nitrogen. An ideal mix for this would be one with an N.P.K. ratio of 3-20-20.
You could also incorporate a slow-release feed into the mulching material, before you spread it around the soil of your planting site, as above. This will feed the soil once watered in, which in turn will feed your trees. This method promotes the relationship between the tree roots and soil microbes, which will help them feed themselves in time.
Pruning Minarette Trees
Young maiden trees (without the development of side-shoots) that are used for vertical growing will need to have their leader stem shortened by one-third each winter, until they reach the top of the planting stake. The impact of this pruning will encourage the lower buds to break, and result in the perfect fruiting tree.
Main side-shoots will need to be pruned back in late autumn time to 3 buds from the main vertical stem, and any sub-side shoots to one/two buds.
In the spring of the second year, carefully remove any premature flowers as they appear, leaving the basal leaves intact. This only needs to be carried out in the second year after planting.
In mid summer to early autumn, cut back any unnecessary side-shoots to three leaves and any sub-side shoots to one bud.
Continue this pruning regime yearly and you’ll have a nice, compact columnar fruit tree.
Pruning Ballerina Trees
We know that the Ballerina group have been bred for their compact shape, perfect for making a columnar tree. These shouldn’t need much pruning: just the occasional shortening of the side-shoots, (to 3 buds from the main stem), and tipping the top leader stem when it reaches the top of your tree stake. Always remove any dead, dying, or diseased branches, and thin out spurs when they start to get congested.
Possible Growing Problems
Your columnar apple trees can suffer from the same pests and diseases as any other fruit trees. Thankfully, their compact shape and height makes treating any problems much easier. There are certain apple cultivars that are resistant to pests and diseases.
“Sunset”, Blenheim Orange is one tree that’s resistant to powdery mildew. “Newton’s Wonder” is resistant to canker, and “Discovery”,” Sunset”, and “Ashmead’s Kernel” are all resistant to scab. It’s worth planting these resistant varieties whenever possible: all are well-known, tasty varieties, perfect for columnar growing on the correct rootstock.
There are many pests that can affect the health of your tree and ultimately, your apple harvests. Below are some of the worst offenders:
- Apple Maggots
- Codling Moths
- Plum curculio
- San Jose scale
There are a large number of all-around, chemical fruit tree sprays that will help combat apple tree pests. Use it after twilight when pollinating insects aren’t around. Remember that a chemical control will often kill off beneficial insects as well as the pests, so try to think about using chemical-free options first.
Use non-toxic, chemical-free horticultural oil in early spring to smother the dormant insects and their eggs. Spray this on your tree before its new leaves emerge.
Insecticidal soap products are another effective way of combating pests—especially aphids, which are the most common sap-sucking insects. These are a biodegradable method of control, but not organic.
Keeping a clean, tidy, weed-free planting area, and raking up all fallen leaves and debris will help to remove any potential hiding places for pests. As a result, this goes some way to eliminating any pest problem.
Diseases and Disorders
The most common problems are:
- Brown rot
- Apple scab
- Apple canker
- Honey fungus
- Poor fruiting
The best course of action is non-chemical controls, including pruning out infected spurs, leaves and fruits, plus proper disposal of affected parts to stop fungal spores from spreading.
Keep a clean, tidy planting area, maintain good plant care, and prune regularly to help keep these fungal diseases at bay.
As with all plants, there’s always a risk of pests and diseases. With proper guidance and good horticultural practices, you’ll find that growing your own fruits is not only satisfying, but an easy way to be just a little more self-sufficient.