All about hibiscus, how to grow them!

All about hibiscus, how to grow them!
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I have heard hibiscus described as the “flamboyant flowers”!
They surely are, and they will only thrive in a warm, tropical climate, although some of the hardier varieties sometimes do okay in hothouses in cooler climates.

Choose a hibiscus plant to suit the position. If a tall plant is required or a low one, choose from in the desired height range, too often we see a huge hibiscus adjacent to a gate, or in front of a window, or a low one in a hedge for privacy, or a wind break.

It is possible to obtain a hibiscus plant tailor-made to your requirements. Growth characteristics of hibiscus vary greatly, they range from low bushes suitable for containers, to trees in excess of 6 metres, ideal for wind breaks or privacy. Flowers can be single to double and come in an array of out standing colour combinations.

In order to obtain the best results from your hibiscus, the selection of planting site is important. Ensure you choose an open sunny position preferably sheltered from the prevailing winds. Full sun is suggested, although hibiscus will tolerate part shade, excessive shade will reduce flower production.

Hibiscus have a vigorous but non-invasive root system, feeder roots are between 30mm & 200 mm deep. Hibiscus look spectacular as a feature or in a special bed on their own, with a minimum of one meter spacing, they also give a touch of class around pool gardens snuggled between palms & rain forest plants. Some hibiscus are suitable for cultivation in patio tubs and are known to thrive for many years in containers.

Hibiscus prefer well drained soil with a pH range of 6.0 to 6.5. Soils with a high percentage of sand or clay can be structurally improved with the incorporation of organic matter worked into the top layer of soil. Once planted, they thrive with generous amounts of mulching which will retain surface soil moisture, and release valuable plant nutrients.

Protect surface feeder roots from temperature extremes & encourage macro & micro organisms within the soil. If good drainage appears doubtful, the planting beds may be raised 14cm to 20cm. Hibiscus cannot tolerate wet feet. This term is used when after rain or irrigation, it takes in excess of 24 hours for puddles of lying water to disperse

Correct preparation of the soil prior to & after planting will ensure vigorous, healthy plants and reduce the problems of after care. Plenty of organic matter should be incorporated & garden lime added annually to adjust ph.

The addition of pelletised chicken manure, blood & bone and a complete blended fertiliser is said to be advantageous. Once added, lightly turn into the soil to about 100mm with a garden fork or spade & allow to fallow for two or three weeks prior to planting if possible.

They do not like being shifted so make sure you pick the right plant and the right spot! Dig the planting hole two or three times the width & depth of the container the hibiscus has been grown in, back fill the extracted soil so as the top of the container soil is slightly lower than the existing garden bed soil level.

Please note if you have purchased a grafted plant ensure the graft area is not covered by soil. Prior to back filling place a one meter garden stake on the prevailing wind side, position as close to the root ball as possible but do not damage the roots.

Lightly tease out roots especially if finger penetration into the root ball is difficult. Back fill soil, excess soil may be billed around the hole edge to retain moisture. Firm in soil to stabilise plant & tie up to the inserted garden stake. Water in well and keep well watered as required. Mulch planted area to a depth of 100mm to 200mm up to, but not directly against the hibiscus main trunk.

Do not feed your newly planted hibiscus immediately after planting as there are enough fertilisers & trace elements incorporated in the plants at point of sale. When the plant has settled in, about one month after planting, encourage more growth with light applications of a complete fertiliser each month during the growing season.

Water in well after each application of any fertiliser. Hibiscus prefer a blend of fertiliser of N P K in ratio 12: 5 : 14. This is available purchased as hibiscus plant food.

Pruning is practiced for a number of reasons but the two main ones being to shape the plant & produce more vigorous growth & in turn more flowers. The ideal time for pruning hibiscus is just prior to the new seasons growth in Spring, usually about September.

Pruning can sometimes be done later in cool regions but never prior to the last frosts expected in frost prone areas. Hibiscus are pruned according to their growth usually about one third as a rule of thumb e.g. if your hibiscus is 3 meters high bring it back to 2 meters with pruning.

Each few years the hibiscus may become woody, & it is advisable to rejuvenate the plant by cutting back severely to the main trunk & three main branches this will revitalise the old plant, & give it a new lease of life.