All you will then need to do is to water and maintain your garden through winter, giving you ample time to snuggle up and enjoy the season.
Members can click on highlighted text to read more about the plants mentioned.
Rose care in March
The last roses of summer are often the most perfect ones, and as the daytime temperatures drop your roses will take on a new intensity of colour and unfading beauty seldom seen in hot weather. Their petals unfurl perfectly and they last much longer too. If the temperatures play along, you can have roses well into April and May.
In hot, humid regions, you can trim your roses lightly if necessary. Do not cut them short as they can produce their most beautiful blooms in autumn.
Shorter days are a signal to roses to prepare for winter dormancy and the plants start converting sugar to starches and storing it in their stems for their spring growth, so it is important to feed them regularly, especially in the summer rainfall regions.
In very cold regions, you should stop feeding by mid-March as this will harden the plants off against the cold. Lower daytime temperatures and reduced evaporation also mean that you can reduce the amount you water by increasing the time between watering’s, while still ensuring good moisture in the soil.
We experience a lot more dew on the Highveld in March, in sub-tropical regions it is still very warm, and in the Cape you may experience a wet autumn. Therefore, in these regions it is imperative to keep on spraying against fungal diseases like black spot and powdery mildew. Also, in hot, dry regions watch out for red spider.
Late summer and autumn are ideal times to plant new roses, when the soil is still warm enough for the plant to produce hair roots. Roses planted at this time will be ready to grow to their full potential in spring and produce their first flush of blooms of the season.
BabianaWinter and spring flowering bulbs arrive in stores this month
Look out for winter bulbs like daffodils, hyacinths etc. which arrive in stores in March, which can still be extremely hot and the soil temperatures are still far too high to plant out bulbs. Store them in a cool, dark and dry place until the temperatures drop significantly in April, or even May.
Tulips are usually available from late April, and Liliums from May.
Consider including some of our gorgeous indigenous bulbs like Babiana, Freesia, Sparaxis, Tritonia, Ixias, Ornithogalum (Chincherinchee) and Lachenalias.
Once your summer flowering bulbs have died down you can lift and store them. If you plan on leaving them in the soil, mark the position where they are planted to avoid damage while they are dormant.
Once your summer flowering bulbs have died down you can lift and store them. If you plan on leaving them in the soil, mark the position where they are planted to avoid damage while they are dormant.
Click here to find my list of winter and spring flowering bulbs.
Dwarf Mixed Snapdragons. Picture courtesy Nu-leaf NurseryPlanting times for a winter and spring garden in SA are in March, April and May.
If you have not done so yet, prepare your garden beds now for sowing and planting out winter vegetables, flower seedlings and bulbs.
Dig the beds over about 30cm deep, working in lots of compost. Sprinkle with a general purpose fertiliser like 2:3:2 (one handful per square metre) and a generous dressing of superphosphate, bone meal or hoof and horn meal.
Flowering Annuals
Some annuals like alyssum, snapdragons, dianthus and petunias can be grown almost throughout the year in South Africa and can be sown now. However, remember that not all so called “winter annuals” are fully hardy to frost, and because local regions can vary greatly in climate within quite small distances, always check with your local garden centre for the exact times for sowing and planting.
In subtropical and humid regions, late summer, autumn and winter are the best times to plant a flower garden
In subtropical and humid regions, late summer, autumn and winter are the best times to plant a flower garden. In these regions many winter annuals, as well as summer flowering annuals are sown during these cooler months. Because sowing times vary from region to region, it’s always better to check with your local garden centre which varieties do best in your region before sowing or planting.
Cold winter regions
In very cold winter regions which experience early frosts, gardeners generally start sowing seeds of slower maturing winter and spring flowering annuals in January and February; keeping them in a cool, shaded area. In these regions, continue to feed the seedlings you sowed; such as pansy, viola, cineraria, foxglove, aquilegia, Iceland poppy, delphinium, larkspur and primula; and transplant them into larger 6-pack seedling trays or small pots to grow-on. Only plant them out into the garden once the soil temperatures have cooled down significantly in autumn.
In other cold regions, many annuals can be sown into seedling trays now, but do not sow winter seeds directly into garden beds until the daytime temperatures have dropped significantly.
Some annuals like alyssum, snapdragons, dianthus and petunias can be grown almost throughout the year in South Africa and can be sown now. However, remember that not all so called “winter annuals” are fully hardy to frost, and because sowing times vary from region to region, it is always better to check with your local garden centre which plants do best in your region before sowing or planting.
Do not plant the same seedlings into the same beds year after year. This can cause soil borne fungal diseases and will deplete the soil of nutrients. This is especially relevant for seedlings like petunia, pansy and viola.
Members can click here to find my list of winter, spring and early summer flowering annuals.
Click here to read my article "10 stars of the winter flower garden"
Vegetables
Sub-tropical Regions
In sub-tropical regions many summer vegetables as well as winter veggies are grown during the cooler winter months, so continue to sow seeds of vegetables and herbs that you can plant out into the garden once the weather cools down, and prepare your beds for planting now.
Cold, Frosty Regions
On the Highveld you need to sow your winter vegetables this month so that the plants can mature before it gets really freezing cold in June and July. You should try to get at least 6 to 8 weeks of good growth on your winter veggies before the major frosts come, anything less and your plants will struggle over the really cold period.
In very cold winter regions which experience early frosts, gardeners generally start sowing seeds of slower maturing winter vegetables into seedling trays as early as January and February, and plant them out as soon as the soil temperatures drop sufficiently. If you live these regions and have not sown slow maturing veggies yet, it will be worth your while to purchase trays of established seedlings from your garden centre to plant out this month.
In cold regions June and July are not good months to sow seeds.
Over the years I have written many articles on growing vegetables at home, and members may also find the following articles helpful.
"Easy to grow winter vegetables"
"When to sow winter vegetables"
"Growing vegetables in raised beds"
"Growing vegetables & herbs in containers"
"Square Foot Vegetable Gardening"
Start treating your conifers in March
Start treating your conifers for the cypress aphid in March. If left untreated, this aphid can cause whole branches, or the entire tree to die off. Systemic poisons work well and can be applied as granules, or as a drench around the roots of the trees.
Herbs
Plant herbs like chives, oregano, parsley, tarragon, thyme and rosemary, they will grow through winter, adding flavour to those comforting winter soups and stews.
Continue to harvest and dry or freeze herbs for winter use. Members can click here to read my article on harvesting and storing culinary herbs.
Below is a short regional summary
Members can click here to read my full article on what to do in your garden in March.
It includes a regional gardening guide; what to do in the late summer vegetable and herb garden; how to grow vegetables in raised beds, which works well for organic gardeners, in both small and large gardens; tips on caring for your late-bearing deciduous fruit trees and citrus, as well as tropical fruits; taking semi-hardwood cuttings from your favourite shrubs; dividing perennials; lawn care and other gardening tips are all included.
TibouchinaSubtropical summer rainfall regions
In these regions many summer flowering annuals, vegetables and herbs are grown during the winter months, so continue to sow seeds of vegetables that you can plant out into the garden once the weather cools down, and prepare your beds for planting now.
In sub-tropical regions March is the last month to plant onions, and April is the last month to plant peppers. Otherwise, cabbage, spinach, beetroot, tomato, beans, peas, coriander, rocket, chillies, carrot, lettuce, gem squash and butternut can all still be planted.
There are many vegetable varieties that are traditionally only suitable to grow in colder climates which have been bred to be more tolerant of warmer temperatures. These heat-tolerant varieties are slower to bolt or produce a seed stalk, and are more suitable for growing in subtropical regions. For this reason it is very important to purchase seeds from a reputable garden centre which will have the correct varieties for your region on their shelves, at the correct time of the year.
Lettuce, cabbage, oriental cabbages, mustard greens, mizuna, Swiss chard, true spinach, endives and kale grow best in cooler weather, and root crops like carrots, beetroot, radishes, parsnips, leeks, late season onions and shallots, kohlrabi, garlic and turnips thrive in winter. Try growing broccoli, Brussels sprouts, cauliflower, celery, broad beans, and peas. Asian greens like pak choi and tatsoi also do best in the colder months.
Click here to find my vegetable growing guide for the subtropics.
Feed your lawn every 6 weeks with a balanced organic fertiliser that is high in nitrogen, and allow it to grow a bit longer than usual. Feed the rest of your garden with organic 3:1:5 and water it in well. Mulch your garden beds to help retain moisture and keep the soil cool.
Prune all your summer flowering shrubs that have finished flowering, including your Tibouchinas which respond well to a heavy pruning every four or five years. If your Strelitzias are overcrowded you can divide them now.
Sweetpeas. Picture courtesy Nu-leaf NurserySummer rainfall (Temperate or Highveld Regions)
On the Highveld Autumn is knocking at the door and there is a slight nip in the air early in the early morning and evening.
In very cold winter regions which experience early frosts, gardeners generally start sowing seeds of slower maturing winter and spring flowering annuals and vegetables into seedling trays as early as January and February, and plant them out as soon as the soil temperatures drop sufficiently.
Continue to feed the slower maturing flower seedlings you sowed last month, such as primula, pansy and viola, cineraria, foxglove, aquilegia, Iceland poppy, delphinium, and primula, and transplant them into larger 6-pack seedling trays or small pots to grow-on.
Try alyssum, snapdragons, stocks, dianthus, bellis perennis, Canterbury bells, candytuft, godetia, lobelia, lupin, larkspur, ornamental cabbage, poor man's orchid, petunias, and sweetpeas.
Wait to sow Namaqualand daisies, Bokbaai vygies, calendula, cornflowers, Virginian stocks, and nemesia until towards the end of March or early April, when the soil temperatures have cooled down significantly. These annuals are easy to grow when sown directly into well-prepared garden beds.
In areas where frost comes later and is not so severe, early March is the latest you can sow slower maturing vegetables like broccoli, Brussels sprouts, cabbage and cauliflower.
As soon as the soil temperatures drop, start sowing all your other winter vegetables directly into garden beds, as this ensures that the plants are established before it gets really cold in June and July. Ideally you should try to get at least 6 to 8 weeks of good growth on your winter veggies before the major frosts come, anything less and your plants will struggle over the really cold period.
Late summer and autumn is the best time to sow Asian greens like mizuna, pak choi and tatsoi. Other crops like celery, lettuce, endives, beetroot, broad beans, Swiss chard, kale, kohlrabi, true spinach, mustard, leeks, late season onions and shallotts, garlic, carrots, radishes, parsnips and turnips can also be sown now. In very cold regions wait until June or July to sow peas, because the leaves are frost hardy but the flowers are tender. Planting them later will ensure they flower at the right time.
You need to harden the wood of your established shrubs and trees at this time of the year to enable them to withstand the coming dry and cold season. This is done by cutting back on the amount of water you give, by watering thoroughly but less often.
If you overwater and fertilise evergreens at this time of the year, your plants will produce lots of soft new growth which will be killed off by the first severe frost. Do not prune your garden too much now because all that summer growth will protect your evergreen plants from the frost. Also, do not mow your lawn too short or it will not recover properly before winter.
Late summer and autumn are great times to plant hardy shrubs, roses and trees, as these will be nicely settled by spring and have a head start when the first rains arrive.
In early March feed your whole garden including your lawn, citrus trees and roses for the last time this season with an organic 3:1:5 fertiliser and water it in well. Never throw fertiliser up against the stems of plants and never apply too much.
Klip Buchu (Coleonema) Winter rainfall regions (Mediterranean)
The end of summer can often be a dry time in these regions, so it is important to continue with responsible water-wise gardening practises.
Planting just before the first rains is perfect timing to plant shrubs and trees so that they will be well established by summer. It is also the perfect time to plant fynbos species like proteas, ericas, leucospermums and leucodendrons; and why not try some klip buchu.
proteas, ericas, leucospermums and leucodendrons; and why not try some klip buchu. Consider planting indigenous bulbs like: Babiana, Freesia, Sparaxis, Tritonia, Ixias, Gladioli, Ornithogalum (Chincherinchee) and Lachenalias.
Winter and spring flowering annuals can be sown into seedling trays now and placed in a cool, protected place. Try arctotois, and the lovely Cape forget-me-not or vergeetmynietjie (Anchusa capensis), aquilegia, alyssum, cineraria, delphinium, foxglove, godetia, hollyhock, stocks, snapdragons, dianthus, bellis perennis, primula, pansy and viola, sweet pea, Iceland poppy, lobelia, lupin, larkspur, ornamental cabbage, linaria, candytuft, Canterbury bells, and poor man's orchid.
Make your last sowings of broccoli, Brussels sprouts, and cauliflower. Late summer and autumn is the best time to sow cabbage, Chinese cabbage, and Asian greens like mizuna, pak choi and tatsoi, as well as traditional crops like celery, lettuce, endives, beetroot, broad beans, mustard, kale, kohlrabi, parsnips, turnips, onions, carrots, peas, Swiss chard, true spinach, leeks, and radishes.
Autumn is a good time to re-pot your outdoor container plants so that they can settle down and make roots while the weather is still warm but not too hot, and to benefit from the first autumn showers.
As the weather cools down, you can start to do some light pruning and tidying up, removing any ugly branches on trees and shrubs and spent flowers. Prune all your summer flowering shrubs once they have finished blooming, as well as your summer-flowering perennials like daisy bushes, salvia and lavender.
Divide agapanthus and arum lilies now if necessary. Remember, agapanthus resent disturbance, so only divide them when absolutely necessary. If you prune down your dianthus and begonias now, and feed them, they will reward you with another flush of flowers in autumn. Mulch your garden beds to help prevent soil erosion when the rains come.
Virginian Stocks Dry, semi-arid and continental regions
Buy your winter seeds now and start sowing as soon as the weather cools down. Try alyssum, aquilegia, bellis perennis, Iceland poppy, candytuft, Canterbury bells, snapdragons, stocks, primula, pansy and viola, sweetpeas, candytuft, delphinium, foxglove, lupin, larkspur, and ornamental cabbage. In brak (salty water) gardens sow hollyhocks this month; they are perfect for these areas.
Wait to sow Namaqualand daisies, Bokbaai vygies, calendula, cornflowers, and Virginian stocks until towards the end of March or early April, when the soil temperatures have cooled down significantly. These annuals are easy to grow when sown directly into well-prepared garden beds.
Make your last sowings of broccoli, Brussels sprouts, Chinese cabbage, cabbage and cauliflower, and in early frost regions it may be best to purchase established seedling of these crops to plant out now. Late summer and autumn is the best time to sow Asian greens like mizuna, pak choi and tatsoi. Also remember traditional crops like celery, lettuce, endives, beetroot, broad beans, Swiss chard, kale, kohlrabi, true spinach, mustard, leeks, late season onions and shallots, garlic, carrots, radishes, parsnips and turnips can also be sown now. In very cold regions wait until June or July to sow peas, because the leaves are frost hardy but the flowers are tender. Planting them later will ensure they flower at the right time.
Start to cut back on the amount of water you give your established shrubs and trees, watering thoroughly but less often. If you overwater and overfeed at this time of the year, your evergreen plants will produce lots of soft new growth which will be killed off by the first severe frost.
Do not prune your garden too much now because all that summer growth will protect your plants from the frost. Do not mow your lawn too short or it will not recover properly before winter.
Late summer and autumn are great times to plant hardy shrubs, roses and trees to ensure that they are nicely settled by spring and have a head start when the first rains arrive.
In early March feed your whole garden including your lawn, citrus trees and roses for the last time this season with an organic 3:1:5 fertiliser and water it in well. Never throw fertiliser up against the stems of plants and never apply too much.
Do not divide your perennials now, rather just tidy them up and mulch them well to prevent the soil from freezing. You can however divide your Bearded Irises now, re-planting only strong healthy pieces and mulching well. Mark the places where they are growing so that they are not accidentally dug up in winter.