Introduction to Mahonia Japonica
Genus: Mahonia.
Species: Japonica.
height x Spread: 200cm x 400cm.
Growing conditions: Full Sun / Semi Shade
Mahonia Japonica are typically grown for there attractive dark green foliage which are made up of long leaves consisting of around 5-20 leaflets depending in the age of the growth. In winter the leaves turn a reddish purple colour and from around late autumn through to winter they then produce long stalked bright lemon yellow flowers which have a scent like Lilly of the valley. The bright yellow flowers shoot out from the ends of leaves, on smaller plants in pots they tend to shoot from the centre of the plant. Once flowered they produce an attractive purple fruit.
Mahonia Japonica is smaller the the ‘Media’ varieties but is still one of the larger varieties and grow to around 200cm tall (6.6ft) but has a spread of 400cm (13ft), they are a very hardy shrub and will grow well in most soil types including heavy clay, sand, moist or dry soils but do need to be planted in well drained soil. Its is also ideal in woodland areas and will grow well in full sun and semi shade but will also survive in shade without any trouble but are better suited in an area protected from cold drying winds which can scorch the leaves and buds in winter. They are also ideal for using as a screen due to there very tall bushy nature and help deter intruders with there very sharp spikey leaves.
Mahonia are very hardy but will benefit from a mulching around the base of plants to protect the roots from frost in serve winters. This is also recommended specially if you have recently pruned your Mahonia back.
Pest and Diseases
Mahonia are generaly pest free but can suffer from Rust and Powdery Mildew but these fungus are easy to spot and can be easly treated with a garden fungicide at firsts signs of infection.
Planting a Mahonia Japonica
If you have purchased a new Mahonia Japonica and want to plant it we recommend using bone meal and mixing it through the soil in the hole before planting, this will encourage new root growth and give the Mahonia a good start. Soak the roots before planting for around 20 minutes and never plant the roots dry.
Pruning Mahonia
Mahonia Japonica are best left unpruned but can be pruned to remove any dead, damaged or diseases growth as well as to try and keep it to a formal shape.
The Royal Horticultural Society has given it its Award of Garden Merit (AGM).