With thanks to our resident gardener Stephen Lee
Hydrangea
This is a genus of 80 species of predominantly deciduous shrubs and climbers. Natively they come from Asia to the Americas but the largest diversity is from China to Japan. They are hardy throughout the UK; however, frosts can affect early leaf growth. These shrubs like to grow in full sun to partial shade. They generally grow to around 6 feet but in partial shade can reach 10 feet or more. In this group of plants, what appears as flower petals are actually bracts. The flower itself can be found in the center of these bracts and is small, star like. They are tolerant of most soils with exception to damp or water-logged soils.
Here’s a few more readily available types of Hydrangea’s ;
Hydrangea arborescens
A deciduous shrub originating in North East America. The leaves are bright green oval with a point. The shrub can grow to 5 feet x 4 feet. The flowers occur from July onwards. There are now a few hybrids of the species,
Hydrangea arborescens “Annabelle”, the most popular in this group. The flowers are borne terminally has large green heads then becoming a brilliant white flower like structures. The flowers can be so large that they need support especially when its wet and can cause the stems to snap under the weight of the water-logged flower. There are now lime and pink coloured flowers in this group.
As the flowers occur on current seasons growth, the woody plants can be pruned hard in late winter.
Hydrangea macrophylla
Originating from China and Japan. Height and spread of this group is 4-12 feet. This shrub grows in a rounded shape with broadly oval toothed leaves, mid green and are shiny. The shrub is deciduous. The flowers are borne in two distinct types, Hortensia (mophead) and lacecap. The flowers are either white, pink, red, purple, bi-colours and blue. This group is also PH sensitive. Some shrubs within both groups can change their colour according to the whether the soil is acidic or alkaline (PH). The more acidic the soil is the bluer the flowers become, and the more alkaline the pinker. However not all can change their colours but its noteworthy to recognize that they can. There are also hundreds of cultivars.
Hydrangea Hortensia – mophead
Small to large rounded oval flower like structures. The small star like flower can be found within the center of the four petal like structures. Some of the flower structures can change colour once the flower itself has been pollinated. For instance, a white flowering hydrangea can change and have pick edges. Also, sometimes intense sunlight can also cause colour changes. However, the biggest change is changing the PH of the soil.
Hydrangea Hortensia – Lacecap,
The flower structure within this group is flat shape with clusters of flowers flat in the center. Round the edge of the flower structure is a ray of sterile four/ five petaled bracts. Its also interesting to note with this group that the inner fertile flowers are often a different colour to the outer sterile bract (flowers). As in Hydrangea Lanarth White
If you wish to produce blue coloured flower heads in this group and do no have acidic soil then you can apply a regular solution of aluminum sulphate or Sequestrene to the roots. I am also told and been led to believe that tea bags or leaf can also be applied to the roots to make the grown acidic but, as yet I have not tried this method
There is a smaller variant of this group and that’s,
Hydrangea macrophylla serrata
This much smaller shrub growing slowly and reaching spread and height of 3×5 feet. It’s much more suited for the smaller garden.
The flower structure from this group is produced on second years wood. This means shoots produced the previous year flower the following year. Previous years flowering growth will also flower.
The only real maintenance is to dead head the old brown flowers in March and any dead wood withing the shrub.
Hydrangea paniculata
Originating from China and Japan. This deciduous shrub produces mid green ovate pointed leaves. The flowers are borne terminally in pyramidal panicles. On the whole in the wild they are white or cream ageing to pink. Although some hybrids can grow to more than 10 feet most are small shrubs growing to a more respectable 4-6 feet. The flowers usually occur from mid-July.
Hydrangea paniculata Limelight
A truly lovely hybrid producing large pyramidal flowers in a light green colour that fades to cream as the flower matures. Also available as Hydrangea “little lime” for the smaller gardens.
Hydrangea paniculata Vanilla fraise
Producing lovely good-sized flowers that open cream and fade to a nice pink with age.
If you want a truly large Hydrangea paniculata, then look at variety called candlelight or Phantom, both of which can grow in excess of 8 feet.
Hydrangea paniculata produces it flowers on current seasons growth. This means that the shrubs can be pruned hard in March. Interesting to note if you don’t prune hard and give a lighter prune in March your get more but smaller flowers.
Hydrangea’s are a very versatile group of plants not only small to large bushes they can also make excellent climbing plant that are self-clinging.
Hydrangea Petiolaris
A self-clinging deciduous climber suitable for a north wall or up a mature tree. The leaves are a mid-green and turn the most amazing gold colour in autumn. The flowers are a typical lace cape style. These will also grow in full sun
Pruning of these is easy. Remove when they try to get in to your roof space or gutters. Remove old flower heads. With mature plants you can cut back to the wall of the structure they grow against. This results in no flowers for the following year as the flowers are produced on wood from the previous year’s growth.
If you want something a little more unusual then go for
Schizophragma intergrifolium.
This climbing version of hydrangea grows in the full sun and is also self-clinging. It has large open lacecap like flowers. The small flowers clustered in the centers and the bracts are a diamond shape. It is also available in a Pink coloured plant too. Most desirable if your looking for something different.
Below is a gallery of pictures relating to August
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