Growing In Small Spaces: Fruit Trees

Returning from the backyard with an armful of freshly harvested fruit is a true pleasure. While sprawling acres make fruit tree growing easy, don’t think you have to miss out if you’re short on space.

Returning from the backyard with an armful of freshly harvested fruit is a true pleasure. While sprawling acres make fruit tree growing easy, don’t think you have to miss out if you’re short on space.

The backyard orchard is a goal for lots of gardeners and the vast array of fruit tree varieties often leads to questions about how to fit it all in, especially if you only have a small piece of land to grow on. Luckily, there are some clever ways to squeeze more fruit trees into tight spaces without compromising on harvest or tree health. Choosing dwarfing varieties, clever planting methods, growing in pots, making use of vertical space and trellising can all help create an abundant fruiting garden in even the smallest yard.

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Espaliered trees are trained flat and require a fraction of the space.

Why Grow Trees In Small Spaces?

While many people with small spaces assume they can’t grow fruit trees, there’s plenty of reasons to do your best to fit them in. Being able to grow and eat your own fruit is of course a huge motivator, and fruit trees provide a high output of fruit compared to the small amount of effort required to maintain them.

On top of providing a delicious harvest, the trees themselves add value to a garden and play an important role as a perennial plant in creating a holistic ecosystem. Visually, trees give form and vertical interest to a garden and can be a feature either in the ground or in pots. Fruit trees in flower are loved by beneficial insects, and in cooler areas provide a valuable food source for bees in spring as they start to become more active. As with all trees, they can also provide beautiful dappled shade when in leaf and are an important habitat for birds, too.

The Tree For Me

The first and most important step in choosing which fruit tree to grow is to only plant what you love to eat. This is especially important if growing space is limited. Consider this in the context of your local climate – this will determine which trees will do well, and which may struggle with pests and disease or poor health. Consider your own microclimate and if you’ll be planting into the ground or growing in large pots. You might be living in a cool temperate area where citrus generally suffer through cold, frosty winters but have a warm north-facing courtyard with a brick wall that retains heat and protects from cold winds, in which a potted lemon would thrive.

The characteristics of the rootstock is coupled with the fruiting type of the scion

Often the heat-island effect of large cities makes them a versatile environment to grow in – it’s possible to get some subtropical or heat-loving fruit trees like avocado, banana or even mango to manage well in cooler climates in this way. If plants are grown out of their ideal climate but can still handle the conditions, you’ll often find they won’t reach their full size potential or will grow quite slowly and, as a result, can be grown in smaller spaces.

Pollination

Another important step is to check if the tree variety you’ve chosen is self-pollinating or if it needs another tree to cross-pollinate with. Fruit like apple, pear and cherry will generally need a compatible pollinator to set fruit while self-fertile trees, including apricot, peach, nectarine and citrus can pollinate alone. Always check each specific variety, as you can often get self-pollinating or cross-pollinating varieties of the same fruit. If you’re really short on space and can’t fit two trees in, check in with your neighbours – they might already have a compatible tree growing close by.

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Train, Plant Or Pot

Once you’ve chosen what you want to grow, think about your growing area. Do you want to spend time pruning, shaping and training your trees along walls or trellises? Would you prefer growing in big pots you can move around (great if you are renting) or do you have space to grow a few dwarf trees directly in the soil?

Some fruit trees or shrubs like pomegranate or tamarillo are naturally smaller, and can work well in tight spaces without the need for dwarf varieties or complex training systems. ‘Columnar’ or ‘ballerina’ apples are bred to grow tall and narrow and require very little pruning, so are great for pots, tight spaces or along fences.

Dwarf Trees

A popular way to grow fruit trees in less space is to plant common varieties in dwarf form. Many modern fruit trees are grown on what’s called a rootstock. This means that one variety of tree (the ‘scion’, or upper part of the tree) is grafted onto the roots and lower trunk of another variety (the ‘rootstock’). The benefit is the growth characteristics and pest resistance of the rootstock is coupled with the fruiting type and vegetative growth of the scion. While this technique is beneficial for pest and disease resistance and to improve the manageability of growth in a commercial setting, it also allows productive varieties of fruit trees to be grafted on to ‘dwarfing’ rootstock.

In this way the overall size of the fruit tree is reduced to around a maximum of two metres tall. While the amount of fruit you can harvest from a dwarf tree will be less than a full-sized tree, you will still get great yields with the added bonus of being able to reach it all from the ground. A useful strategy is to plant several dwarf trees of complementary varieties that ripen at different times to create a rolling harvest of homegrown fruit to pick throughout the season.

‘Top-working’ is a form of multi-grafting, where an established fruit tree has one or more limbs cut back and other varieties are then grafted onto them. This means the established root system is maintained and the existing tree regrows the newly grafted varieties. This is helpful if you have older unproductive trees you want to refresh.

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Clockwise from top When planting a grafted tree, always keep the union proud of the soil surface; Trees in pots can be moved to make the most of warm areas; Create a ‘fruit salad tree’ using grafts; Tall and narrow, a columnar apple doesn’t need a lot of space or maintenance.

Multi-Graft Trees

Multi-graft trees, sometimes called ‘fruit salad trees’, are a fun way to maximise your fruit harvest. With a multi- graft, two or more different varieties of the same type are grafted on the same tree. This means you could have one tree with multiple varieties of apples, pear or citrus for example, growing on different branches of the tree.

Multi-grafts are an excellent option for those with very limited space, especially if you are needing to meet cross- pollination requirements, with both the complementary varieties grafted onto the same tree. One downside can be that different varieties may grow at different rates or have different pruning needs, so just be aware of this when choosing your tree.

Duo Planting

Duo- or trio-planting is a technique that can give you a similar outcome to a multi-graft by planting two or three fruit trees of the same type in the same planting hole. Choose compatible trees that are a similar size (both at planting and at maturity), and make sure you dig a hole wide enough to take both root systems. It’s important to leave at least 15 centimetres of space between the trunks so they have room to grow. Plant the trunks slightly angled out away from each other to minimise the number of branches that will grow inwards and cross each other, as well as the amount of pruning you’ll need to do to keep the middle clear for good airflow and sunlight.

Be prepared to repot a fruit tree every couple of years, either in the same pot or by upsizing

The beauty of this method is that because the trees are growing in the same soil space and competing for nutrients, you’ll most likely end up with a smaller tree that’s easier to maintain and satisfies any cross- pollination needs too. Fruit trees well suited to duo- or trio-planting include pear, apple, cherry, apricot, nectarine, peach and plum.

Growing In Pots

If you are renting or only have a courtyard or balcony, growing fruit trees in pots could be a great solution. Most dwarf varieties of fruit trees can be successfully grown in large containers with consistent care and regular watering. Choose the largest pot you can, within reason – a bigger pot means a bigger root system and more space to grow into, but also means the potted plant will be a lot heavier; a pot that is at least 50 centimetres in diameter is recommended. Be prepared to repot the fruit tree every couple of years, either into the same pot by refreshing the soil mix and trimming the roots when the plant is not actively growing, or by upsizing the pot. Planter bags can be a good alternative to rigid pots if you need to move them around often or want to minimise the weight.

Use a high-quality potting mix, plenty of good organic compost and add an organic slow release fertiliser on top, and take care to not bury the graft union (where the scion and rootstock join).

When growing in a pot, the tree is reliant on you for all its needs, so water it regularly and use mulch to reduce how quickly the soil dries out. Conversely, make sure the pot has good drainage because waterlogged soil will very quickly kill your tree. A regular application of liquid fertiliser and seaweed extract will help the plant to stay healthy and support it to produce fruit.

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Most fruit trees are available in a dwarfing variety.

Making Use Of Your Vertical Space

Utilising walls or fences in your garden is a clever way to make the most of limited growing space. Many fruit trees, particularly dwarf varieties, are easily trained along fences, trellises or over arches, with popular choices including apple, pear, quince, apricot, plum, citrus and even pomegranate.

There are lots of ways to train fruit trees in narrow spaces with a common method being ‘espalier’, where a spur-forming plant like an apple is trained to grow horizontally along a trellis. This can be done on a wall or a fence, or using a free-standing trellis. There are many different applications of espalier, from a T-shape or multiple-stacked T-shapes, to the short ‘step-over’ espalier kept to less than a metre off the ground. A fan- shaped espalier is best used along walls or fences. Any type of training will require a bit of effort to set up, as well as ongoing maintenance and pruning, but the pay-off in increasing your useful space is worth the effort.

Fruit tree guilds

Whether growing in the ground or in a pot, a fruit tree guild uses the space directly beneath your trees to grow complementary plants in a way that is similar to companion planting, or by growing a living mulch. Choose low- growing plants that provide a dense cover to exclude weeds (strawberries), have extensive root systems to capture nutrients (comfrey), improve the soil (clover) or that flower abundantly to attract in beneficial insects (nasturtiums) to reduce pests and disease, and boost pollination.

Pip ran an in-depth feature on the hows and whys of fruit tree guilds in Issue 23

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