May in the garden
Gardening in May is like putting a baby to bed. You clean it up, feed it, play awhile, kiss it goodnight and cover it warmly with a blanket. Remember to also kiss your mom and spoil her with a lovely plant on Mother’s Day!
Rake up all fallen leaves and lay them on garden beds as a mulch. Mulching is like a blanket – it protects the roots from the cold, keeps in valuable moisture and improves drainage.
Many winter annuals are now available as healthy seedlings, such as pansies, violas, calendulas, primulas and snapdragons. Plant them in great swathes around spring-flowering bulbs like daffodils, anemones and ranunculi.
Hot tip: Something in the wrong place? Now is the time to move established shrubs and trees to a different spot.
Rake fallen leaves off the lawn to prevent them from blocking out sunlight, and place them on the compost heap. At the coast you can still apply one more dose of fertiliser before winter sets in.
Interplant leafy winter veggies and root crops with herbs like lavender, thyme, oregano, parsley, yarrow and comfrey.
Winter is on our doorstep, so brighten up your garden beds by planting some colourful annuals such as poppies, pansies and petunias for the sun, or primulas in the shade.
Stalwart perennials like Michaelmas daisies, obedience plants, penstemons, yarrows, gaillardias (blanket flowers) and chrysanthemums will stop flowering. It is now time to neaten them by cutting them back. If their clumps have become too thick, you can divide and replant them too. If you prefer to wait until spring, simply add a layer of compost around their root areas.
Prune back plectranthus after flowering, and use the clippings as cutting material to grow more plants (in a protected area, as they are tender to frost).
Add eye candy with rows of ornamental kale between other winter vegetables. Good winter companion plants for kale are beetroot, violas and pansies (which both have edible flowers), onions, nasturtiums and spinach.
Nandina domestica is the heavenliest ‘fake bamboo’ available! In large pots they bring good luck to your front door, they are the ‘zen’ in Zen gardens, and you can plant them in a row in the narrow space between the house and a boundary wall, and they will soon supply a lacy look with their rust-tinted leaves, and height with their tall-growing branches. Bright red berries will delight you from now until spring.
Protect your conifers against conifer aphids preventatively with a system foliar spray and/or soil drench.
Water winter crops like lettuces and cabbages regularly, mulch warmly with straw and fallen leaves, and feed every two weeks with liquid fertiliser. Start covering plants against frost at night.
Get your winter bulbs into the ground, and remember to dust them for worms before planting.
Hot tip: For very sunny spots, try some indigenous flower mixes in bumper seed packs – they will reward you with splashes of bright colour. For shady areas try primulas and cinerarias.
Transplanted roses and any other shrubs must be drenched after planting with a liquid kelp to avoid transplant shock.
Cut back any summer bulbs that have died off. Mark the spot where they are planted so that you don’t dig them up accidentally.
Tie up climbing sweet peas and spray them with a soluble fertiliser high in potassium to encourage flowers.
Protect young vegetables against insects with a contact insecticide, and foliar feed with an organic liquid fertiliser.
Sow flowers like sweet peas, marigolds, dianthus, nasturtiums, verbenas and violas.
Consider any Hibiscus rosa-sinensis variety like ‘Brilliant’ (with red flowers) for a large flowery hedge – they love a subtropical climate and are at their best now.
Rose care in coastal areas: Spray rose bushes with fungicides every two weeks until June. The longer you can manage to keep foliage on plants, the better chance the woody stems will have to ripen, resulting in better blooms in spring. Also feed all rose bushes one more time and water weekly.
Feed avocado trees with 3:1:5 fertiliser and mulch. Plant litchis and citrus and keep mango trees dry before the flowering starts.
Pull up old sweet basil plants, chop them up and use them as an insect-repelling mulch around cabbages.
Spectacular autumn colours in yellow, orange, red and maroon hues will be seen everywhere. If your garden doesn’t have such an element yet, consider planting a liquidambar tree or two.
Hot tip: The fairy primula is the answer for shady sections of the autumn and winter garden. They brighten up these dull areas with their multitude of blooms in shades of white, mauve, rose and wine red. Also plant lots of foxgloves, which produce tubular flowers on tall spikes in a variety of colours. A word of caution: foxgloves are highly toxic, so don’t plant them where animals and children have access.
Sow broad beans. They germinate and grow easily, and they produce heavy crops of pods throughout winter and into spring. All you need is a sunny spot and good soil preparation before planting the seeds.
Fill up window boxes and hanging baskets for patio colour. Use trusted perennials like gazanias, geraniums, diascias and osteospermums.
Hot tip: When thinking about lush baskets and window boxes, think about tougher options in the form of succulents like echeveria, crassula and kalanchoes.
Look out for ants and treat nests with ant bait or spray. Also look out for products that eradicate the whole nest, including the queen.
Sow winter-flowering annuals like Namaqualand daisies, poppies, calendulas, nemesias and Virginia stocks. If you have already planted some pansies, nip out the first flowers to encourage bushy growth ahead of flowering.
Start planting bulbs towards the end of May. Plant out batches of daffodils, ranunculus and anemones in weekly intervals to extend their flowering time.
AIoes will start blooming soon, so it’s an ideal time to increase your collection. They are great to attract and feed the birds going into winter.
Bougainvilleas are at their best in winter: feed them with organic 3:1:5 fertiliser and water well only when fertilising.
Watch out for fungal diseases like rust and black spot on your roses, pelargoniums and geraniums. Spray the entire plant as well as under the leaves with fungicide.
Sow vegetable crops like peas, cabbages, carrots, cauliflower, spinach and onions.
As soon as dahlias have died down completely, they can be lifted, cleaned up, dusted with a fungicide powder and stored.
Sow some wild grass seed somewhere in your garden to encourage birds in winter. These seed mixes are widely available in seed packets.
Cymbidium orchids and cyclamens will be coming into flower now. Create an elegant and long-flowering look in the lounge by combining them with dried moss as a decorative mulch in a smart dish or antique soup tureen.
Snails will be looking for places to overwinter. Check under containers and clumps of perennials where they will huddle together, and put out fresh bait amongst young veggie seedlings.
Hot tip: Plant rows of tatsoi and pak choi seedlings (Asian greens) and sow rocket and radishes between them. Water regularly in warm weather. The result will be tasty, peppery leaves to chow on.