If you intend to plant apple trees, it is very important to know something about soil preparation and soil testing before you even start. If you want the tree to carry fruit, you have to prepare the soil through tillage and you have to add organic matter well in advance of planting.
Prior to planting, you should test the nutrient levels and pH levels of your soil. This can be done by leaf analysis. They reflect the nutrient levels in the plant most effectively. Or you can analyze the soil for acidity. If your soil is poor in nutrients, you have to use manure.
To measure the acidity of the soil, you have to know the pH level of it. To do this, you have to take a soil sample. It is recommended to do this every three years, to make sure the pH stays at a satisfactory level. A low pH level points to acidity. The target pH for an orchard should be around 6.5 on sandy soils and 6.0 for clay soils. When the pH level is lower than 5.6, you should add lime to the soil. Use lime high in magnesium on soils low in magnesium.
You can manure the soil by adding, for instance, animal manure. This contains varying levels of nutrients and organic matter, but has the disadvantage of the nitrogen in the manure releasing over a prolonged period of time. This can result in poor fruit color, excessive terminal growth and delayed hardening of the woody tissue. It also makes trees more susceptible to winter injuries.
No more than 7 t/ha of poultry manure, 40 t/ha of cattle or 35 t/ha of hog should be applied. Since manure is extremely variable in nutrient content, please check the content before application. Also, when you use animal manure, it is best to reduce the rate of fertilizer.
The best all-purpose fertilizer is a balanced one (8-8-8 or 10-10-10). Alternatively, you can try a 5-10-10 or 10-20-20. You should avoid fertilizers specifically formulated for acid loving perennials. Also avoid so-called ‘bloom or fruit’ boosters with a very high middle number (for instance 10-50-10).
You should fertilize your apple trees two times a year, once in May and once in July. Do not do this in late autumn, as this will stimulate tender, late season growth which could be injured in winter.
You go ahead by spreading the amount of fertilizer per 100 sq as is stated on the label of the fertilizer. This calculation can be done by multiplying the radius (the distance from the trunk to the edge of the overhanging branches) by itself and then by 3.14. If directions say to use 1 lb/100 sq feet, you would use ¼ lb to cover the area under the canopy (reach of the branches).
Spread the fertilizer evenly in a circle around the tree.
A note of warning: If your trees grow on the lawn, you do not have to spread special manure or fertilizer around the trees. They will get all their nutrients from the lawn fertilizer you use.