Plants: Azalea japonica 'Johanna' - Japanese azalea

15.02. 2008 08:33:56 (Milan Havlis)
Topic: Plants / Evergreen Shrubs

Azalea japonica 'Johanna' - Japanese azalea

Japanese azaleas are very popular features of our gardens. In their home climate they grow to relatively substantial shrubs, as opposed to limited sizes in our continental, dry climate.

Azaleas are very floriferous, maintenance-free shrubs that bloom from end April until end May. Johanna is extremely popular for its deep red flowers anddark leaves. It flowers so abundantly that leaves almost disappear under the cloud of flowers. It is a slow grower forming a nice, mounding, compact shrub.

Small, ovate to rounded leaves are mid green as they emerge, turning to deep burgundy red later. In semi-shade and shade they remain on the shrub throughout winter, if placed in full sun it might lose some but is more reliable than other Japanese azaleas.

Japanese azaleas can be clipped to shapes in early June. If so, do not use fertilizers enhancing growth rate. The size of new branches would get out hand and spoil the shape you are going to achieve. They need light, permeable soil that is acid, constantly moist (keep azaleas mulched at all times) and moderately fertile. Use fertilizers for rhododendrons and azaleas, or ericaceous plants. The best soil mix is 1/3 of peat, 1/3 of leaf-mould or lime-free compost, and 1/3 of soil from the hole where you are going to plant it. Azaleas have shallow roots, so do not plant not too deep. They are fully hardy to about -29°C (USDA zone 5).
Milan Havlis, Specializované zahradnictví
Chlumec 23, 382 32 Velešín, Czech republic