Firstly, growing fruit trees in containers is a great option for permaculture gardeners who are short on space. They may not have garden beds with sufficient room to accommodate a fruit tree with its spreading roots, particularly if they want to grow as much variety of plant life in a small bed as possible (by inter-planting, for example). The technique is also useful for those who don’t have the option of planting directly into the ground, perhaps because their property only comes with a paved courtyard or small patio as its outside space. Growing fruit trees in containers is ideal for permaculture gardeners who are renting a property. It can be disconcerting in the increasingly unreliable rental sector, to put effort into establishing and nurturing a garden only to then have to vacate the property and leave the garden in situ (although doing so can be considered a gift to the subsequent inhabitants). Growing in containers allows renters to take their fruit trees with them when they move house.
However even without space constraints or the desire to have transferable plants to move between properties, cultivating fruit trees in containers can have benefits for many permaculture gardeners. It can allow you to have fruit trees in zone 1 next to your property (when fruit trees planted in the ground are typically located in zone 2 or 3). This can be particularly beneficial for elderly or disabled gardeners who have restricted movement. It also allows you to move the trees around so that you can take advantage of available sunshine (which fruit trees prefer a lot of to help them set and grow crops). This can be very useful if your site is surrounded by tall structures that cast shadows across the plot. With container planting you can move the tree to match the trajectory of the available sun. Furthermore, if you live in a location that experiences very cold winters container planting allows you to move the tree indoors on the coldest night to protect it (particularly useful in the first couple of years when trees are in their juvenile stages).
Choosing a tree will depend on your tastes, your available space and your climatic conditions. Most citrus trees will thrive in pots, as will an olive. If you want to plant apple or pear trees, you will probably need to select a variety with a dwarf rootstock so that it doesn’t grow too big. Larger fruit trees can be container grown if combined with espaliering on a trellis or fence, which will spread the weight of the tree across a wider area. Take into account the pollination requirements of the species – whether they are self pollinating so you only need one specimen in order to set fruit, or whether you require at least two individual trees to cross-pollinate one another.
There are several things to consider when selecting the container in which to house your fruit tree. Size is garden-pots-315197_640important. You want to ensure that the container is big enough to accommodate the tree when it hits maturity. There is a school of thought that trees grown in containers should not be placed in too large a container in the first instance, and should be transplanted to successively larger pots as they grow. However, this can mean extra energy and expenditure, and with the right growing medium and care, a tree should be fine if planted in the one container throughout its growth stages. The weight of the pot is also a consideration, in conjunction with then weight of the tree, growing medium and water that will add to it (which is important if you are housing your container somewhere that may have structural weight issues, such as a rooftop of balcony). Terracotta pots are heavy, but provide good ballast in strong winds, while plastic containers are easier to move but not as sturdy for withstanding weather conditions that may affect your site. If using a recycled container, make sure it is well cleaned to remove any potential pathogens. In all cases, ensure the pot is as high as it is wide, and has drainage holes in the base to prevent waterlogging.
Most fruit trees grown in containers prefer a loamy soil that will not get waterlogged, but which has enough structure to provide a stable growing environment. Adding compost to the soil will help the trees establish themselves. It is often a good idea to add some stones or gravel, to the base of the container before filling with the growing medium, to aid drainage. Make sure you plant the tree so that the surface of the soil is level with the top of the rootstock; you do not want the soil covering the trunk as this can promote rot.
Fruit trees grown in containers will need more regular watering tan those planted directly in the ground. The comparative lack of depth of the soil in a container means that it dries out more quickly. Keep the growing medium moist but not damp. Mulching can help preserve soil moisture – use woodchips or straw so that the mulch is breathable and allows aeration of the growing medium. You can give the trees a nutrient boost by replenishing the compost in the growing medium each spring. Replace the top five inches or so with well-composted organic matter. If you have selected a fruit tree variety that is suitable for your size of container, it should be fine as it grows. However, if the tree does start to become to large for its container, you have two options. You can, as mentioned above, transplant it to a larger container, or you can prune the rootstock. To do so, gently lift the tree from its container and identify the taproots. These are the larger roots and the main engines of growth. You don’t want to prune these; rather you want to prune the thread roots that branch off the taps. Also cut away any roots that look dead. Replant and water well.