Some of the stand-out plants of the season observed were the magnificent hydrangea paniculata varieties.
Some of the stand-out plants of the season observed were the magnificent hydrangea paniculata varieties.
The summer garden can be a magnificent sight, highlighted by some of the garden displays in the heritage weekend Arthritis Garden Ramble. I took some time out see some of the marvellous gardens along the ramble.
Some of the stand-out plants of the season observed were the magnificent hydrangea paniculatavarieties - these include hydrangea limelight, hydrangea strawberry fraise and hydrangea candlelight.
These types of hydrangea come into their own in mid-to-late January, taking over from the more ‘traditional’, well-known ‘mophead’ hydrangea varieties to provide colour through the rest of summer and even into the autumn months.
Another winner in the summer months is the perennial gaura, or butterfly bush. These plants thrive in bright sunshine and heat. The gaura is remarkably drought-hardy and will produce colour for months throughout the year.
Other spectacular flower plants at the moment include: bougainvillea, mandevillea, silk trees, jacaranda, petunias, tropical impatiens, flame vine and tropical hibiscus.
The summer months can be a time when substantial growth can occur on trees and hedges if they are kept moist. If you are growing plants to create privacy, then ensuring they are well watered and well fertilised during the summer months will encourage much faster growth than during cooler times of the year. Plants such as pittosporum, griselinia and many other natives, evergreens and deciduous trees will react in this way. The wet months during October, November, December and early January have created phenomenal growth on trees around the city in recent months.
A way to help plants during the summer months is to mulch the soil around them. Mulching is the spreading of a layer of organic matter on the surface of the soil with the aim to improve moisture retention, supress weeds and provide a cooling effect on the soil and root system below.
Mulching will improve soil structure, and encouraging earthworms and microbial activity will give better results for both new and existing plantings. As the saying goes, ‘the answer lies in the soil’ in regards to success or failure in the garden. If you have seen the growth that can be achieved, particularly in Taranaki soils or Westmere loam, then you will agree with this statement.
Another winner in the summer months is the perennial gaura, or butterfly bush.
There are a number of different mulches available that will best suit different plants and soil types. At the garden centre, we have bulk landscape supplies of these and other products, and it has been an interesting exercise to source and develop products suitable to specific plant types and categories.
Some of the options available for mulching are poultry compost, tūī mulch and feed, mushroom compost, peat moss and pea straw.
Hibiscuses are one of the heat-loving plants of summer.
Hibiscuses are amongst the most favoured shrubs for tropical, subtropical or warm temperate gardens. In Whanganui, some grow more vigorously and bloom better than others. In selecting hibiscuses, keep an eye on gardens nearby to you for robust, free-flowering plants to give you ideas for obtaining good plants for your own situation. Hibiscuses, if regularly fed and watered, respond with healthy growth and displays of superior flowers. They have a strong appetite and need to build energy reserves for constant flower production. An annual feed with Novatec fertiliser is recommended.
Some early references claim the geographical origin of Hibiscus rosa-sinensis, which literally means ‘rose of China’. Various forms eventually found their way to England. Others suggest it hailed from India. Captain James Cook and other Pacific explorers later found a double red form being cultivated in several island groups. Early botanists suggest Polynesian migrants may have brought Hibiscuses with them from South East Asia and then to Hawaii, Tahiti and Fiji. The earlier crossing of Chinese and native Hawaiian species has resulted in the development of most of the thousands of hybrids grown today. There is much diversity of form, colour and sheer beauty in hibiscus flowers.
Hibiscuses grow best in maximum sunlight. They will grow in the shade, but need full sunlight for optimum flower production. If you can, avoid placing them with other plants which compete for available root space and nutrients.
Growing hibiscuses in containers is an ideal way of enjoying a beautiful hibiscus at close range. In reasonable conditions, they will thrive on sunny patios, balconies, by swimming pools, etc. Pots are best with a minimum size of 50 centimetres in diameter. Use a good-quality potting mix with a long-term slow release fertiliser incorporated. Re-potting is generally necessary after two years. Appropriate feeding, pruning and pest control is desirable. Regular watering is essential, and a fitted irrigation micro-tube with adjustable micro-spray or dripper fitting makes this easy to manage.
Annual pruning of hibiscuses is encouraged for healthy growth, good flower production and neat, compact plants. When the season begins to warm up in the spring, remove about one third of the previous season’s growth. Use sharp secateurs and make an angled cut above the outward pointing bud. Completely remove crossed or wayward branches, or any which overcrowd the centre of the bush. Trim off branches within 30cm of the ground to create clearance for mulching, fertilising, etc. Bushes soon grow into vigorous new stems.
If you enjoy hibiscuses, I encourage you to find space for one more. If you are just beginning and have yet to experience the delight of picking a hibiscus bloom from your garden, then consider giving one of these a go.
