In late summer, many gardens reach their full beauty.
Bedding plants are at their best and brightest and the orange and yellow marigolds and the various colours of petunia, lobelia and geranium brighten many a border, pot or container and hanging basket.
Another flower at its best is the tropical impatiens with their bright red, pink and white flowers making a stunning display - a good addition for a shady spot.
One of the heat-loving perennials that has caught my eye this summer is the gaura.
Commonly known as the "butterfly bush", these plants stand up to the full sun and flower prolifically through these hot summer days.
They are dry hardy and a number of varieties are available, in colours ranging from pinks, rose to pure white.
They generally form a small bush approximately 30-40cm high and wide. If you have a little gap where you would like summer colour then I highly recommend these.
Another of strong recommendation is the recently released salvia amistad.
Salvias are long known for their hardiness to drought, hot sun and constant flowering.
The wider family is a diverse range of varieties in many colours, flowering from summer through late into the autumn months.
Salvias are part of the mint family, also referred to as sage. Like the herbs, the leaves are delightfully aromatic when crushed.
In Latin the name salvia means "healthy, feel well or to heal", given the healing properties of some varieties.
Amistad is a recent release into the populous world of salvias.
It has exquisite deep purple blooms, which emerge from black buds.
They put on a stunning display on top of its tall stems of green foliage. It is reputed to flower from spring until the first frost and through the winter months in warmer areas. Salvia amistad has coined the common name of "the friendship plant" as the word "amistad" is Spanish for friendship.
Amistad is easy to grow in well-drained soil.
Feeding annually in spring will encourage lush new growth and good flowering for the coming season.
The plant should be trimmed after flowering or whenever it gets untidy. If necessary it can be cut back to 15cm high, from which fresh foliage and subsequent flowers will arise.
Amistad can be grown in pots on the patio for colour, right through the summer BBQ season or it is great in the garden where it will reach 70cm high, providing height and depth of colour.
Summer lilies are another favourite blooming at the moment with many varieties releasing a fragrance that makes the air heavy with a sweet scent.
English lavenders and a number of roses will produce another flush of flowers and grace many a garden with a blaze of colour.
Agapanthus are looking stunning, as are the summer flowering gum trees (eucalyptus ficifolia) now flowering around Whanganui.
Often at this time of the year gaps can appear in borders.
Planting perennials such as the mentioned guara and salvia that flower later in the summer will help keep the borders bright over the next couple of months. Other late summer and autumn flowerers to look out for include chrysanthemum, rudbekia, echinacea, dahlia and alstromeria.
Climbers such as clematis, honeysuckle and pandorea envelope fences and scramble up pergolas, trellises and over arches, to offer privacy and seclusion. Roses require attention at this time.
Spent blooms should be removed at regular intervals during the flowering season, not only for the tidiness of your plants but also to prevent the formation of seed heads, which wastes the plant's energy.
When flowers or spent blooms are cut, a reasonable length of stem should be removed. New shoots have generally started to develop on the old flower stem and a clean cut should be made just above one of these.
This will encourage healthy growth and more flowers.
If your soil has acidic tendencies or if heavy dressings of organic materials are applied annually, then a light application of lime will be of benefit around your roses.
When feeding, make sure the fertiliser contains sulphate of potash, which helps to harden growth and makes the plant less susceptible to disease. Potash will aid flowering and may also help to intensify colour in the flowers.
Feed roses using Yates Dynamic Lifter, Novatec or Tui Rose Food.
Keep an eye out for the spread of pests and diseases on roses.
Maintain regular sprays to control aphids, rust and blackspot. A good spray is Combat 3 in 1 for Roses - a combination spray of insecticide, fungicide and a natural fish fertiliser with minerals and trace elements.
Ensuring your roses are well watered and fed is your first defence against pest and disease.
February is the first of the bulb planting months. In stores soon will be ranunculus and anemones in mixed and individual colours as well as crocus, hyacinths and daffodil bulbs. They are excellent for borders, garden edges, pots and tubs as well as great to grow as a cut flower. More about bulbs in the coming weeks.
A note about watering
As mentioned in previous columns we are very lucky in Whanganui to have an excellent water supply that does not rely on rainfall.
This enables gardeners to water all year round without the restrictions common in some areas of New Zealand.
At this stage of the summer I recommend a walk around your property to check on the health of the plants in your garden, particularly looking for signs of water stress. Gardens are best given a couple of deep waterings each week rather than a little sprinkle each day.
This method of watering encourages roots to search deep for water rather than remaining close to the surface in expectation of another light sprinkling.
Larger shrubs and trees will benefit from a hose left on drip overnight and shifting the hose around the property each morning is a good strategy to keep your plants healthy.
Soaker hoses (a porus type of hose, where water seeps through the hose) are also highly effective as they deliver water directly to the soil.
The hose can be weaved through a garden bed underneath the desired plants where the water is delivered directly to the roots of the plants.
This method of watering reduces the amount of water on the leaves. Water on the leaves, particularly at night, increases the risks of fungal diseases such as mildew. The best time for watering the garden is early in the morning.
Applying mulch to the soil during the summer season will help to conserve moisture and to keep the soil cooler; it will also reduce weed growth and can make the watering you do more effective and longer lasting.
It is best to apply mulch after the garden has been thoroughly watered.
Have a good week.
• Gareth Carter is general manager of Springvale Garden Centre