Although many Hydrangeas are seen existing with little or no attention, they do respond positively to extra care. Photo / Supplied
Hydrangeas have surged in popularity in recent years. They are on trend as classic, no-fuss old-world plants.
Their large, full lush blooms carry happy memories of our grandparents who also loved them.
They are reproduced as faux flowers as well as dried and dyed for year-round displays indoors in public places and modern interior decorating around the home.
Freshly picked in a vase they last well too.
Growing in the garden, hydrangeas are star performers in the summer months.
The blooms start in late November and carry on through Christmas and into January and February. Some will have blooms that will stay on the plant into the autumn months changing colour to antique shades as the flowers age.
The most familiar hydrangea are “macrophylla” hybrids, which means long or large leaves. The bold heads bloom in white, pink, red and blue in summer. The macrophylla types include “mop head” and “lace cap” forms.
The mophead is recognised as the “classic” hydrangea with a rounded flowerhead, and the lace cap has a flatter flower head with florets around the blooms while the centre has the appearance of an unopened bud.
There is another range of hydrangea which are “paniculata” varieties.
These plants are later in their flowering with blooms generally starting in December or January.
The paniculata types then carry on later in the season with blooms still coming on in March and April. The blooms of these start off white and then develop varying colours according to their varieties which are unaffected by soil pH.
Although many hydrangeas are seen existing with little or no attention, they do respond positively to extra care. The flower colours can be controlled and intensified and bloom greatly enlarged with feeding and annual pruning.
Fortnightly liquid feeding now during the growth period after the flowers have formed will encourage enormous-sized flower heads.
Hydrangeas vary in flower colour according to soil acidity or alkalinity. Blue colours may be retained in acid soil situations, this can be created if not naturally occurring with applications of aluminium sulphate applied at monthly intervals during the winter months and prior to flowering.
Red and pink colours occur in alkaline soil situations, applications of garden lime will make the soil more alkaline to keep these colours vibrant. These pH-adjusting products are available in the garden centre in both liquid and powder forms.
The white flowers stay true to name in both acid and alkaline soil situations.
Some brilliant hydrangeas include:
Hydrangea Bridal Bouquet - This mophead form has pure white blooms, and grows about 1m x 1m.
Hydrangea Renate Steiner – A strong blue mophead form, grows approximately 1m x 1m.
Hydrangea Strawberries & Cream – Puts on a spectacular show with lace cap blooms contrasting a strong show between red florets and cream centres. Grows about 90cm high x 120cm wide.
Hydrangea White Wave – A lace cap form with white florets surrounded white centre with blue tinges, highly attractive. Grows approximately 2m x 2m.
Hydrangea Sabrina – A lovely dense vigorous shrub with bronze-coloured leaves. In summer large clusters of mophead flowers appear which are white with red margins. A very beautiful shrub which is easy to grow and thrives best in part shade. Grows approximately 90cm high and wide.
Hydrangea Goldie – A superb plant to lift a shady area with gold-green-coloured leaves. The white mophead-type flowers make an attractive show. Grows approximately 1m x 1m.
Hydrangea Limelight – A paniculata variety producing masses of lime-green flowers through the summer months. An amazing display of flowers in the heat of summer. Grows about1.2m high x 1m wide
Hydrangea Paniculata Annabelle – This Hydrangea hails from the USA and is commonly known as the “Smooth Hydrangea” because of the thin, soft heart-shaped leaves. Large heads of white flowers open from green buds in summer.
The flowers turn green again as they age. Very hardy and will flower well even if cut back quite hard each year. Grows approximately 1.8m high x 2m wide.
Insect pests
The warming temperatures that are promoting good growth in the garden are also resulting in a rapidly expanding population of aphids, whitefly, caterpillars, scale, potato/tomato psyllid and other attacking insects.
We recommend a good “bee-friendly” insect spray “Yates Mavrik”. This spray works on contact with the insect.
This means that to break the life cycle of an infestation a few sprays in quick succession will be needed to knock back the population.
Follow all packet directions carefully when spraying for pests and diseases, care should be taken so that the spray reaches both sides of the leaves to get an effective result. An organic product Naturally Neem can be used for aphids, whitefly, thrip and mealy bug.
I have recently read a recommendation of mixing these two products to good effect. Mavrik works by contact and ingestion, while Naturally Neem stops feeding and disrupts the breeding cycle. A mixture of Yates Mavrik with Naturally Neem offers a two-pronged attack giving particularly effective results. This combo works on all chewing and sucking insects. Once the spray is dry, it is bee-safe. It can be used on vegetables and has a three-day withholding period.
“Combat 3 in One for Roses” is a good rose spray. Combat is the only three in one - insecticide, fungicide and fertiliser, especially for roses.
Combat is marketed as a rose spray but is also suitable for other ornamental plants. This weather has been great for the bugs - beat them to the draw with Combat.
Another range of products that has recently come to my attention, particularly for the treatment of psyllid on potatoes and tomatoes is the “Wally’s” range of silicon products. These products work by making the plant’s cells too tough for the psyllid nymphs to pierce and feed from.
Definitely, something to try in the battle against these destructive pests.
For more gardening information visit www.springvalegardencentre.co.nz
Gareth Carter is the general manager of Springvale Garden Centre
OPINION: The colour of picked rose blooms offers vibrancy and life.