Tuesday, March 28

Admiring the ‘candy’ colours of hydrangeas


As temperate-climate plants, hydrangeas require a cool environment, sheltered from sunny mornings and hot afternoons. Good drainage is also essential, especially in our high-rainfall country.

I HAVE been receiving questions from many online friends, who are curious about hydrangeas. Some ask about growing and caring for this beautiful flowering plant in the home garden, and some want to know more about the types of hydrangeas that we have and those from overseas.

This brings me back to a garden in Christchurch, New Zealand where it grew really well and bloomed like it was nobody’s business.

Strolling along the streets there, it was easy to spot the large globes of pinkish or blueish flowers, which truly enhanced the appearance of the garden.

Mainly used for hedge-planting and other landscaping purposes, the hydrangea is considered as a shrub plant, able to grow up to a height of 10 feet (over 3 meters) and has several side branches that give it a bushy appearance.

Hydrangea is grouped as dicotyledons – namely, the seed has two embryonic leaves, or ‘cotyledons’. Ranging over 100 species, some of them are herbaceous, and some are climbing plants.

The main characters are the opposite or alternate arrangement of leaves, and the clustering inflorescences. The main colours are blue, pink and white.

The plant belongs to the family Hydrangeas under the name Hortensia’s, with some lower classifications that include ‘Panicked hydrangea’, ‘French hydrangea’, and ‘Tea Heaven’, together with many hydrides and cultivars – either from the Chinese form of H. maritima or the Japanese H. Macrophylla and H. serrata sources.

Hydrangeas with round heads of fertile blooms are distinguishable from the flat heads. These are known as ‘lace cape’.

As temperate-climate plants, hydrangeas would require a cool environment, sheltered from sunny mornings and hot afternoons.

However, avoid planting it directly under trees as this could lead to competition for water and nutrients.

Hydrangeas love to grow in soil abundant with organic materials. Good drainage is essential, especially in our high-rainfall country.

They cannot tolerate waterlogged or soggy soils, which can rot the roots leading to its death.

Any heavy soil needs to be mixed with plenty of compost prior to planting. The nature of the soil can affect the colour – alkaline soil can result in pink or red flowers, while acidic soils can result in blue or purple blooms.

Putting in lime in the ground has the effect of locking up aluminium and other elements so that the plant cannot get them. If aluminium sulphate is applied round the roots, crimson pigments would turn blue.

For pot-planting, it needs to consider the depth and width of the roots sphere as the plant matures. It is advised to choose a pot with diameter of up to 15 inches and height up to 18 inches, for the plant to bloom easily.

Ground-planting, on the other hand, requires digging the planting hole wide and deep to loosen the compost soil for mixing with organic compost.

The plant is best planted slightly above the ground to avoid water gathering at the base which, as I said before, could cause root rot.

After-cares and nutrients can be added to achieve a healthy plant. It is best to run a soil test to ensure the pH set for the colouring of the blooms later on.

A general-purpose fertiliser of 10-10-10 or 12-4-8 ratio should work well for hydrangeas. Apply slow-release fertiliser twice per year around the drip line of the branches, instead of the base of the plant. It is good to cover it with a layer of fresh soiI.

Get rid of spent flowers or deadheads to maintain good growth and further blooming.

It is good to try our green fingers in nurturing the colourful hydrangeas, so as to be able to enjoy the ever-changing colourations of such an exotic flowering plant.

Happy Gardening!