All year round stalwarts
Alice Spenser-Higgs discovers flowering plants that fill the gap between summer and winter
AUTUMN is well on its way and although it is too early to plant winter annuals there are plenty of plants that fill the gap and keep on flowering into winter.
There are the “all year round” stalwarts like alyssum, dianthus, lobelia, gazania, delphiniums, mimulus and verbena as well as those with a particular cool season preference such as argyranthemum, antirrhinum, osteospermum, plectranthus, and zonal geraniums.
Perennials that flowered in spring will be coming back for their autumn flush such as coreopsis, gaillardia, rudbeckia, agastache, asters and red hot pokers (Kniphofia).
Winter cut flowers Having cut flowers in winter is entirely possible if you choose the right varieties and grow them in a sunny, sheltered bed. Cut flower varieties that can be sown in March are Antirrhinum Tetra Mix consisting of selection of colours,
Calendula, Delphinium Pacific Choice Mix, Larkspur, Statice Pastel Shades Mix, Stocks Giant Imperial Mix and Sweet Peas Mammoth Choice Mix. These varieties as well as calendulas should also be available as seedlings from garden centres. The cut flower Di- anthus Amazon is not available in seed packets but only through garden centres and it is worth looking for. It has vibrantly coloured serrated-edged flowers on glossy dark green foliage.
The colour range is Neon Cherry, Neon Duo (cherry and purple), Neon Purple and Rose Magic. It performs as a landscape and bedding plant that attracts butterflies and grows to about 60cm tall.
Indigenous autumn flowers Autumn is a good time for indigenous gardens. Red hot pokers (Kniphofia), Strelitzia, aloes, bulbines, osteospermum and plectranthus flower at this time. One of the newest plectranthus varieties on the market is the shrublet, Cape Angel that has resulted from a cross between Plectranthus saccatus and Plectranthus hilliardiae. The compact bushes grow 60cm to 80cm tall and come in a variety of colours, of which the white Snow Angel is the showiest.
The Cape Angels have a long flowering period and grow easily in shady parts of the garden and can even take morning sun. The same cross of species resulted in the popular cultivar Mona Lavender, which has purple flowers and leaves with violet undersides.
Like all Plectranthus they can be cut back quite hard at the be- ginning of spring. They are not frost hardy but tolerate the cold if grown in a sheltered position, under trees or with other shrubs. They should be well mulched and watered regularly but do tolerate neglect.
Another new introduction is the Osteospermum Voltage. It has bright yellow daisy like flowers and a low spreading habit that makes it suitable for landscapes as well as in hanging baskets and containers. Pinching back the young plant will encourage it to become bushier and bear more flowers. It is quite different to the Osteospermum Serenity series that are more upright, mounded plants, growing 25cm to 35cm high and wide. They are drought tolerant so should be watered regularly but the soil should never be sodden. They can be pruned lightly after flowering to maintain their shape and extend the lifespan of the plant.
Garden tasks Overgrown clumps of perennials like agapanthus, irises, day lilies and perennial grasses can be divided and replanted. Water camellias and azaleas regularly to encourage the development of spring buds.
Start planning and preparing beds for spring bulbs but only plant towards the end of March and in early April. Keep your lawn green during winter by fertilising now with Ludwig’s Vigorosa and water regularly.
Another way to keep the lawn green over winter is to over-sow with a cool season grass like Evergreen. Towards the end of the month, sow colourful winter flowering Namaqualand daisies, calendula, Iceland poppies, Primula malacoides, Scatter pack Indigenous Mix and Shirley poppies. For fragrance there are sweet peas, Virginian stocks, alyssum and nemesia. Namaqualand daisies should be sown directly into the flower bed.
Rake the soil lightly to cover them and compact the soil by pressing down with your hand or a wooden board. Water regularly until they germinate and keep on watering until they are well established little plants. Then you can reduce watering.
The best place to grow sweet peas is on a slight slope. Slopes provide better drainage, especially in winter rainfall gardens.
Prepare a trench with composted manure mixed into the subsoil and bonemeal into the topsoil. Top this with a light layer of sand and plant the seed. Sand helps seed germinate quickly. Sow seed this month or in April for an early crop of flowers.
Osteospermum 'Voltage' ideal for hanging baskets