In early spring; incorporate fertilizer to soil around shrubs and trees at a rate of 115 g (1/4 lb) per metre (3 ft) of plant height. Water well. Repeat every 5 weeks; but do not fertilize after the end of july. Plants may be fertilized in late fall to increase carbohydrate reserves before winter. Perform a soil test to verify pH level. To acidify the soil in the event of very high pH levels (alkaline); use Nuway soil acidifier: elemental sulphur according to recommendations.