Watering !!
It is important to cover the soil with a layer of bark mulch, peat soil and/or fir soil. This way you prevent the upper roots from drying out. As of March/April, according to the weather conditions, it is important that you supply the Rhododendron, Azalea or Pieris with extra water. You preferably do this during the morning or evening. You are advised against watering especially in the blazing sun during daytime. The amount of water depends on the location and type of soil, but it is advised to water long enough until the entire root ball is moist.
Fertilizing
During growing season, from April until October, the plant needs extra feeding in order to obtain an optimal growth. There are two ways of fertilizing the plants; Preference can be given to composed artificial fertilizers N-P-K (N=nitrogen, P=phosphorus, K=potassium) with a formula made for acidophil plants. These must be applied in March/April, end of May and end of June. Especially take care not to apply too much at once and to avoid the stem (mind fertilizer burns !!) The second option is the application of an artificial fertilizer with a layer of resin, in other words, the ‘coated’ fertilizers are released in a controlled way, as with Osmocote, for example. There are compositions for Ericaceae which are effective from 3 up to 9 months. These efficient fertilizers are on sale in any garden centre. Of course, the use of dried cow manure or decomposed stable manure are recommended as well, however, also here it is a general rule not to apply too much at once.