Growing fruit in containers

Many fruit trees or vines can be successfully raised in containers. Within the average suburban allocation, container planting enables a wider diversity of species to be trialled, particularly when there is an appreciation of the various micro-climates and other growing conditions. In most regions it is important to make use of sunny, but reasonably sheltered spaces around walls, pathways, trees, and other decorative features. With the exception of very large specimens, container growing has the advantage of portability. Containers can be moved to accommodate seasonal shifts and to avoid the impact of storms and predatory insect attack. Water supply and drainage can be closely monitored and problems are often easily fixed, before any serious damage is suffered by plants.

Growing fruit in containers can be particularly suitable when a large section of garden is devoted to vegetables or flowers. Depending on the type of fruit chosen, watering and cultivation requirements may be incompatible with other plants. Despite their need for individualised attention, fruit trees and vines will benefit from basic organic techniques such as natural soil enrichment and companion planting.

Most reputable organic nurseries, offer an excellent variety of miniature fruit trees and vines which should be acclimatised and suitable for localised conditions. Smaller growing citrus trees like mandarins, cumquats, and meyer lemons grow well in large containers. When maintained in healthy condition, the trees should have glossy green leaves throughout the year and delightfully fragrant blossoms in Spring. Upright varieties of apple and pear grafted onto dwarf rootstock are also well suited to container growing, particularly in cooler climates.

Some other fruits to consider for a container garden are figs, avocado, olives, guava, and lychee. A good strategy involves choosing a selection which provides edible fruit several times throughout the year. An alternative is to focus on those seasonal fruits which can be readily preserved in jams, chutneys, and relish. Some gardeners prefer fruit trees that require little or no maintenance while others base their selection on favourite and preferred eating varieties. Several popular fruit species can be challenging to raise on account of their predisposition to disease or complicated pollination requirements. Examples include stone fruit like cherries, peaches, and some of the traditional varieties of grape and strawberry.

It is most important to choose the correct size, shape, and composition of container for fruit trees and vines. While attractive to look at, very small pots and containers can be difficult to manage, mainly on account of their tendency to absorb heat rapidly and dry out.  This drying will often create a surface crust which repels water and prevents normal drainage. In these situations the container must be removed from direct sun then placed in a bowl of water to enable the plant roots to absorb moisture from below. Containers made from plastic and other synthetic compounds are inexpensive to purchase but do not contribute much in the way of aesthetic beauty or elegance. In addition to this, the manufacture of plastic releases toxins which are damaging to the environment. On the positive side however, plastic is considerably lighter and less prone to breakage than other suitable materials.

The traditional material for garden containers is terracotta, beautiful in appearance due to variations in colour and texture which become exaggerated with weathering. Due to their permeability, terracotta containers generally require more frequent watering than plastic. Concrete is somewhat less permeable than terracotta however the larger sizes are terribly heavy and awkward to move about. Don’t even think about moving them when they are planted out with soil and potting mixtures.

Depending on the style of garden, various discarded objects can be recycled for good use. Once drainage holes are drilled into their base, empty wine barrels make suitable containers for small fruit trees. Old fashioned laundry tubs make excellent containers for spreading vines such as grapes, blackcurrant, and passionfruit. When correctly chosen, the original container will be sufficiently large to accommodate the mature specimen, without the need for replacement or replanting. 

When preparing a container, ensuring adequate drainage is the initial and most important priority. A layer of broken crock, bricks, or volcanic stones is followed by several inches of coarse gravel, raked level. Before proceeding it is a good idea to pour water over the gravel and ensure that it drains rapidly through the holes at the base of the container. The next layer is the humus rich potting mixture that will provide essential nutrients, as well as sufficient water and oxygen for the growing plants. The potting mixture can be prepared with natural organic ingredients or one of the commercially blended organic varieties which avoid the artificial fertilisers and other chemically treated ingredients. An even sprinkling of sandy soil can be used for the uppermost layer, allowing the container to remain unfilled by at least an inch. The new container should be watered and kept moist until planting. The ideal situation is for the mixture to support an even distribution of moisture. Elevating the containers on bricks or other suitable supports, will enable excess moisture to drain freely from the holes in the under surface. This practice prevents easy access to many crawling insect pests and also protects against invading roots from grasses and weeds.

Unlike container grown herbs and most flowering annuals, fruit trees and vines need to be provided with additional nutrients, particularly when the fruit is beginning to set. Immature trees need to become established before regular manuring due to the sensitivity of their roots. A few handfuls of old, well rotted compost or very weak liquid manure can be sparingly applied to young trees every few months. Once established, small amounts of organic compost should be mixed into the surface every other week. Worm compost is a very complete source of natural nutrients. Another option is to use finely shredded seaweed or dried horse manure sourced from organic certified pasture. These treatments should prevent the mineral deficiencies which frequently underlie fruit rotting and crop failures. To discourage disease, fallen fruit and leaves must be removed each week. Any fruit exhibiting symptoms of fruit fly or other infestation should be excluded from the compost heap and safely buried or incinerated.

To bear a decent crop of organic fruit each year, most container grown fruit trees require some periodic shaping of their branch and foliage structure. Organic tree nurseries tend to shape their juvenile trees into a chalice configuration with multiple branches spreading outwards to provide an open centre. An alternative is the pyramid shape with a well defined vertical trunk from which a fixed number of lateral branches radiate. The chalice configuration is particularly suitable in colder climates since it allows more sunlight to reach the central portion of the tree. In very dry and heat prone areas, the pyramid shape provides additional shade and sun protection for the centre. Pruning container grown fruit trees follows a similar pattern to ground dwellers, although spatial awareness and physical access should be easier for the container grown specimens. In general terms, efficient pruning techniques require an ability to visualise and work within three dimensional space. Similar to sculpting and other creative pursuits, pruning depends on a number of skills which can be gained through a combination of careful observation, practice, and critical evaluation.