ABOUT OUR HYDRANGEAS
The first Hydrangea plants were introduced from China in 1798. The mop-head and lace-caps of today descend from plants native to a small area in eastern Japan. They are long lived plants, easy to grow, thriving in shade, woodland gardens and near the coast, whilst they also thrive in sunny sites and shady spots. Their flowers range through green, white, pink, blue, red and purple. The flowers give a fine display from June until November.
The traditional Hortensias (H. macrophylla), have two basic types of flowerheads:
LACE-CAPS are usually flat with small flowers without petals in the centre and showy flowers with petals on the outside.
MOP-HEADS have a ball of flowers at the end of the stems of the current seasons growth.
Other Hydrangeas Paniculata and Quercifolia types have panicles of flowers which are very showy and cone - shaped.
PANICULATA Hydrangeas are native to southern and eastern China, Korea and Japan. The paniculata flowers are the same colour in all soil types. Usually opening white and changing through the season to various shades of pink, green and red depending upon variety.
QUERCIFOLIA - Oak-leaved Hydrangeas are native to south eastern United States. As with paniculata Hydrangeas the flowers on quercifolia Hydrangeas are the same colour on all soil types. The flowers open white and turn pinkish towards the end of the season.
Most Hydrangeas form round bushes between 1m and 3m tall. There are also some types that are climbers, which are all lace-caps.
The nursery owners, Roger and Fiona Butler have a collection of well over 250 varieties including many recent introductions of new varieties bred for growing as pot plants or for cut flower production. These are now available for sale.
WHERE TO GROW HYDRANGEAS
Hydrangeas need little attention and are easy to grow. They like damp situations and benefit from light shade. They will tolerate full sun or shady positions on a north wall. They do well on most soil types, except shallow chalky soils or very dry banks. They always benefit from having plenty of humus (compost or manure) in the soil.
The growth rate of your plant will very much depend upon the soil, weather conditions and how well the plants are cared for. Hydrangeas will grow on any soil, however the colour of the Hydrangea macrophylla and serrata types will vary with soil type.
Hydrangea macrophylla and serrata - Blue or Pink?
The flowers of the pink Hydrangea macrophylla and serrata varieties usually go blue in acid soils, but stay pink in alkaline soils and vice versa. The paler pink varieties change to the brighter blue, the darker varieties tend to change to more purple/violet shades. White varieties do not change colour. The ideal soil pH to grow blue Hydrangeas is 4.5 to 5.5. If you want pink Hydrangeas the ideal pH is 6.5 to 7.0. If you have alkaline soil and wish to turn pink Hydrangeas blue you should apply 'Hydrangea Colourant' at the manufacturers recommended doses.
If you are growing plants in a container use an ericaceous compost to produce blue flowers. In the second year in a pot you will need to apply 'Hydrangea Colourant'. If you have an acid soil and wish to turn your blue Hydrangeas pink you should apply lime to the soil.
Hydrangea paniculata and quercifolia varieties are the same colour in all soils.
PLANTING TIPS FOR HYDRANGEAS
When ready for planting, prepare the ground by digging over thoroughly and incorporating farm yard manure, peat or well rotted compost into the area to be planted. Apply a general fertiliser as per instructions on the container (Bonemeal, Blood fish and Bone, Pelleted Chicken Manure or Growmore).
Dig out a hole large enough to allow the roots or root ball to spread out into. Refill the hole with a mixture of good top soil and peat, compost or farm yard manure. Firm in the plants well. Water well particularly in the first year and especially in dry weather and for summer planting.
DO NOT plant into frozen soil.
Pruning Macrophylla and Serrata varieties.
Remove dead heads in spring (late March/early April), and thin out weak and dead stems. You can thin the brown stems to get larger flowers. Do not prune in the autumn as the old flowers give some frost protection to young shoots in early spring. The brown flower heads also look great in winter when covered in frost. If you need to shorten the plant always cut above a bud.
Pruning Paniculata and Arborescens varieties.
There are basically three ways to prune Hydrangeas paniculata and arborescens varieties.
Cut back to 2 buds on previous year's growth in early spring.
This will produce fewer but very large flowers.
Cut back to 4 buds on previous year's growth in early spring.
This will produce more medium size flowers.
Remove last year's flower heads and lightly prune to reshape the plant.
This will allow the plant to produce large numbers of smaller flowers.
Pruning can be carried out from the end of February until the end of April. The later the pruning is carried out the later the plants will come into flower. If you prune your plants hard you may need to support the flower stems as the flowers may tend to flop due to the weight of the flower head.
Other Hydrangea cultivars, quercifolia and aspera, only need minimal pruning in spring to remove dead heads and to reshape the bush.