Hydrangea macrophylla 'EXPRESSION'® mop-head hydrangea

Expression® hydrangea belongs to the modern group of mop-head hydrangeas that can flower on both old and young wood. This variety bears double flowers and its colour is determined by the soil acidity. If you want clear pink flowers make sure your soil is alkaline: pH level of 6-6.2 (to achieve this add dolomitic lime). But if violet-blue flowers are required your soil has to be very acidic with pH of 5 (aluminium sulphate will do the job or plenty of pure peat). If you are unsure about your soil pH buy a simple testing kit.

It produces large, globular, mop-head flowers on both old and new wood so you don’t have to worry about pruning or unexpected frost or any other damage. You will always have flowers. This variety is supposed to start blooming on the first hot days of spring which is usually mid June here, and will continue until the first frosts. Deadheading will enhance flowering and speed up forming of new flower buds. The leaves are deep green and thicker compared to common hydrangea. The plant grows slowly and remains compact.

Grow it in fertile, moist but well-drained soil, you should never let the soil dry out especially in the first year before it gets established. The name hydrangea suggests it will need a lot of water but should never stand in water in heavy clay soil. It will love part shade or filtered sunlight, you can also grow it in full sun if you provide extra watering on hot days. Good mulch is advisable at all times. Fertilizing is crucial for this type of hydrangea if you want a pretty plant with many flowers. Fully hardy to -27°C (USDA zone 5b).

Last update 25-11-2010.