For many city dwellers, gardening is limited to containers that can be kept on a patio or balcony. Container gardening continues to grow in popularity as people discover the wide variety of plants that can be grown in pots. The list of plants suitable for container gardening isn't limited to only herbs, vegetables and ornamentals. Although it's harder than growing trees in the open, with a little extra time and attention, even apples trees can successfully be grown in pots.
Choose a pot for the apple tree carefully. Consider not only the appearance of the pot, but the size. It isn't easy to transplant an apple tree from one pot to another, so it's best to begin with a large pot. Keep in mind that the pot will be very heavy once it's full of potting soil, so if you want a moveable tree, purchase a pot on wheels, or set it on a wheeled platform. Clay or terracotta pots will be the heaviest, but also the sturdiest. Plastic pots aren't as sturdy and will be easier to tip over, but are much easier to move. Whatever pot you choose, be sure it has good drainage in the bottom.
Purchase a commercial potting soil that has perlite added, and that has been enriched with compost. Put several broken shards of pottery on the bottom of the pot to keep the soil from leaking out of the drainage hole, and then fill the bottom of the pot with potting soil.
Locate the graft union on the trunk of the apple tree. This will be a lumpy spot where the tree was grafted. If the tree is in a pot, cut away the pot carefully and loosen the roots slightly if they seem to be impacted. Plant the tree in the prepared pot with the graft union level with the top of the pot, and continue filling the pot with potting soil. Leave at least 2 inches at the top to allow for watering.
Push a stake or piece of bamboo into the soil and tie the apple tree loosely to the stake with soft twine or a piece of torn nylon stocking. Water the apple tree until water comes out the drainage hole.
Water the apple tree regularly. Keep the soil moist, but be careful not to waterlog the roots. Purchase a good-quality fertilizer formulated for fruit trees, and use it as directed on the label. Gradually reduce the amount of fertilizer in autumn, and don't fertilize the apple tree during the winter months.