Tikorangi is technically in a temperate zone although its mild conditions mean that many subtropical plants can be grown successfully outdoors in the garden, including citrus all year round, avocados, sapotes and many tender ornamentals such as vireya rhododendrons. The banana palms need to be covered in winter in order to crop, but the rest of the plant material takes care of itself.
Summers are relatively cool with daytime average around 24 degrees Celsius. Winters are mild with a daytime average around 14 degrees Celsius. Being within five kilometres of the coast, there is not great variation between day and night temperatures. The disturbed westerly air pattern keeps air moving and stops any temperature extremes.
The few frosts are usually minor – a degree or two of ground frost at the most.
Sunshine hours are high at 2500 hours. On average, 150cm of annual rainfall is relatively evenly distributed throughout the year. Serious droughts are unheard of – 3 weeks without rain and we start talking of drought. The garden is never watered and does not need an irrigation system.
The area has friable and fertile volcanic soil, the legacy of the volcanic Mount Taranaki about 40 kilometres away. In such benign conditions, gardening is a year round activity and there are seasonal flowers in bloom every week of the year.
The opening of the first blooms on Magnolia campbellii in mid winter heralds the start of a new gardening year. These appear in very late June or early July, so technically in the depths of winter. In the deepest days of winter (late June and July), it is a reminder of what is to come but winters are comparatively mild and there continue to be plenty of flowers in season – camellias, evergreen azaleas, daphnes, winter flowering bulbs including carpets of species cyclamen as well as galanthus and early dwarf narcissi, early magnolias, vireya rhododendrons, michelias. It is possible to garden for flowers all year round in this climate.
Spring comes early in August and continues through until the end of November. It starts with the magnolias, Prunus campanulata and early spring bulbs and ends with the sino nuttalli rhododendrons and deciduous azaleas. Michelias flower right through spring, along with a range of rhododendrons and orchids. As spring progresses, the irises come into bloom as do the roses.
Summers are mild, rarely hot, and extend from December to late March. They start with the higo iris in the park and reach a climax with both the auratum lilies and the naturalised Scadoxus muliflorus ssp katherinae. The recently developed summer gardens showcase perennials and grasses while hydrangeas, bromeliads and vireya rhododendrons light up woodland areas.
By the end of March, day length is shortening and nights are cooling, a sign that autumn has arrived, triggering the blooming of nerines and other autumn bulbs, sasanqua camellias and luculias. In the summer gardens, the salvias and asters bring colour and the grasses are an autumn delight. With such a heavy emphasis on evergreen plants in NZ where almost all native flora is evergreen, autumn foliage colour is more in spot highlights than a mass display. The acers, particularly the Japanese maples, colour well as do some but not all of the flowering cherries and grape vines. The large metasequoia, deciduous taxodiums and glyptostrobus in the park also take on autumn hues.
Often the leaves have not finished falling before the cycle starts again with the first blooms on Magnolia campbellii.