It’s April in Georgia, so upcoming garden musings may be a little azalea- and dogwood-centric. Without further ado, the subject at hand is the Korean azalea Poukhanense (Rhododendron yedoense ‘Poukhanense’).
Korean azalea Poukhanense is hardy to Zone 4, so northern gardeners who dream of azaleas in their gardens should take a good look.
Regarding hardiness in northern climates, Poukhanense azalea will be deciduous. Even in southern gardens I notice some leaf drop during winter, although down here I would still resolutely consider Poukhanense evergreen. Foliage may turn a beautiful reddish-orange in the fall.
Flowers are of the softest lilac, appearing shell pink in the golden light of late afternoon. Blooms are classic funnel shape, and Korean azalea Poukhanense blooms in April in the south and May at its northern reaches.
Korean azalea Poukhanense is a slow-grower to a height of 4′-6′ and reputed spread to 12′; I note ‘reputed’ because I have never seen Poukhanense in the garden with a 12′ spread, although I have faith in the source.
Exposure is morning sun and afternoon shade. Filtered light is about perfect. Gardeners who fail with azaleas normally do so for one of three reasons:
- Afternoon sun – it is a killer of azaleas in the south.
- Planting too deeply – Azaleas have short fibrous roots. Gardeners new to azaleas should plant shallower than think they need (rootball an inch or two above existing soil grade is great). It is an overstatement, but simply placing the azalea on top of the ground would be better than sinking it too deeply.
- Alkaline soil. Azaleas need acidic soil. Here in the Piedmont, I have never taken a soil test for pH, as our soils are reliably acidic (with the occasional exception of new houses that may leach alkaline properties into the soil around the foundation). In other areas, it is crucial that you ensure your soil is acidic. If soil is not acidic, then amend with mulch and fertilizer created specifically for acidic plants (often called a ‘rhododendron azalea mix’).
We have no shortage of Kurume varieties such as the much-loved Coral Bells azalea, but it may be interesting to know that the Korean azalea Poukhanense is the parent of many evergreen azaleas in cultivation today.