Heavy clay is not the most ideal medium for planting and growing fruit trees because it has poor drainage capabilities. Most trees won't grow well in soil that does not drain. Clay soil drainage can be improved to make it hospitable for trees by adding organic amendments, which boost the soil's ability to drain while adding nutrients that the tree will utilise as it grows. As organic soil amendments are added to the planting area, they change the soil structure over time.
Plant in a location that provides full sun and soil that is not swampy or boggy. A south-facing hillside is a good choice.
Dig up 1.5 kg (3 lb 4 oz) of soil from 10 locations across the planting site. Mix the samples in a bucket. Spread the samples over a newspaper to dry. Scoop 350 g (1 cup) of soil into a plastic freezer bag to take to a county extension service. An agent at the county extension can help locate a soil laboratory and may be able to help with packaging and submitting the sample. Test results from soil laboratories generally are available within four weeks.
Break up the soil in an area three times as wide as the tree's root ball and to a depth of 30 cm (12 inches), using a rototiller. Spread a 10 cm (4 inch) layer of soil amendments over the soil based on the recommendations made by the soil testing results. Good soil amendments for heavy clay include compost, peat moss and pine bark mulch. The pH of acidic clay soil can be raised using dolomitic lime and lowered by adding sulphur. Mix these soil amendments into the soil, using a rototiller.
Dig a planting hole for the fruit tree twice as wide as the tree's root ball but no deeper. Place the tree in the hole so that the top of the root ball is flush with the soil surface. Fill in the space between the root ball and the planting hole walls halfway with soil from the planting hole.
Water the planting hole to dislodge any air pockets. Fill in the planting hole the rest of the way with soil. Water again until the soil in the planting hole is damp.