Gardenias Are Warm Weather Favourites


Gardenias have become firm favourites with New Zealand gardeners. Their evergreen good looks and their refined, white, stunningly perfumed flowers have seen their popularity skyrocket in recent years.

In many parts we are anxiously waiting for the first gardenia flowers to appear. Gardenias will grow well out of their preferred tropical or warm climate native habitat, even tolerating a little frost, but they can be slow to bloom in cooler areas. Best flowering occurs when days are warm, even though nights are still reasonably cool. Usually by Christmas time, though, gardenias are in full bloom.

To flower well, most gardenias need a position with some sun. They’ll grow in full sun in cooler areas but, in most climates, their favourite aspect is morning sun and afternoon shade.

Water the plant regularly but make sure the water can drain away. Dry gardenias will drop their buds and, possibly, some of their leaves. Mulch over the root system with an organic layer (milled cow manure is ideal) and make sure that potted gardenias, particularly, aren’t allowed to dry out between waterings. In very dry periods it can be helpful to mist spray water over the leaves on hot days, although not when the sun is directly hitting the plant.

Feed gardenia plants a couple of times a year with a slow acting, general fertiliser such as Acticote or Dynamic Lifter Flower Food. Another option is to feed every two weeks through spring, summer and autumn with a liquid like Thrive Roses & Flowers Liquid Plant Food.

Sometimes in spring the old leaves of gardenias turn yellow. This is usually caused by the magnesium in the older leaves moving into the new ones. Mostly the problem rights itself as the weather gets warmer, but a spring treat with a fast-acting liquid plant food like Thrive can hasten the improvement.

Watch for scale and sooty mould on the leaves. Spray with Conqueror Oil. Wait for a number of weeks and, after the scales have died, the mould will gradually fall away.
Gardenias will take quite hard pruning, which can be done in late winter/early spring in most areas.

There are many gardenia cultivars but a perennial favourite is Gardenia augusta ‘Florida’, a medium grower with mid-sized blooms. Gardenia Veitchii is a good, general variety, too. There are some taller growing gardenias such as Gardenia ‘Professor Pucci’ or if you have a garden in a warm district with lots of room and want something really different, grow the tall (to 3-4m), South African gardenia called Gardenia thunbergia.


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Annual Garden Calender