IT IS AMAZING how quickly plants are recovering from our record cold winter now that spring is here. So start removing any dead leaves from large plants like Dracaenas, Cordylines and giant Strelitzias, but go easy on woody shrubs and climbers such as Bougainvillea, always checking for green stems before cutting back. Don’t be scared of trimming tips and pulling browned leaves off Dracaena draco (dragon tree), like the Yucca, it will grow new leaves even from a stump.
Citrus trees need careful inspection and any frosted fruit and decaying leaves should be removed to avoid fungal infection. Badly frosted citrus trees can be hard or lightly pruned according to taste. With regards to painting the ends of stumps and large pruned branches, the horticultural jury is divided on this one, although lately it has swung in favour of leaving them to heal naturally.
Gardening down under
Having just attended an RHS conference and show in London entitled ‘Plants from down under’ it seems to me we have a great deal to thank Captain Cook, Joseph Banks and the crew of the Endeavour for. In 1779, against amazing odds, they brought back a ship full of plants from Terra Incognita Australis setting in motion a transformation of the Mediterranean landscape. The list includes Grevillea, Eucalyptus, Acacia, Callistemon, Melaleuca, Dodonia, Alyogyne, Banksia, Leptospermum, Hardenbergia and numerous others we take for granted. Strangely, however, Australia does not feature any succulents – these mostly originate from the Americas.
A real eye-opener were the displays of Australian plants we don’t grow here. For example, Melaleuca, which is used extensively for hedging here, has a beautiful pink flowering variety, and one seldom sees Callistemon pallidus (Lemon bottlebrush). There is something unexpected about seeing a mass of greenish-yellow bottlebrush flowers.
But there is nothing unexpected about Dicksonia antartctica, which has starred in just about every TV garden makeover programme. Not surprisingly, garden centre customers frequently request this strikingly architectural tree fern. Ironically while adding tropical splendour to thousands of suburban gardens, it does not grow easily in hot climates. It needs partial shade, warmth and above all summer humidity to really thrive. You will find it growing freely in Sintra and all points north, but seldom anywhere along the Algarve, unless in a shady moist courtyard. If you really want to push the boat out, go for Australia’s grass tree, Xanthorrhoea, which is easy to grow in dry sandy soil. However, plants have to be imported and their price reflects the decades it takes to reach maturity.
The Protea family, with its brilliantly coloured thistle-like flowers, is another highly desirable antipodean plant, but unfortunately is hard to cultivate here. At first glance, Proteas are likely candidates to be grown in a natural habitat of poor soil, low rainfall and warmth. However, I would not be tempted by the specimens offered here – unless purely as a pot plant, and even then they may not survive. Proteas need water and soil that is neutral or ideally acidic, perfect drainage and cannot tolerate any phosphates which are widely found in proprietary composts and fertilisers.
One aftermath of the winter is the need to replace perennials in pots and planters that succumbed to the cold. As an alternative, why not consider having some containers planted with cacti and succulents to make striking and low maintenance displays? We tend to take succulents for granted because they grow so easily and often confine them to massed border plantings. Yet even the most humble aloe or agave can look striking in a pot.
The secret is to remove lower growth to reveal stems and present a bonsai-like appearance. Also trim off brown ends of leaves and keep soil away from lower leaves and any branches that might cause the base to rot. Localised decay on cacti and succulents is often caused by debris such as soil splashes or leaves and seeds falling from nearby plants so it is important to clean these off where possible. A mix of sharp sand with a ground tree-bark based compost suits most succulents and it is a good idea to fill the bottom of large pots with small pieces of polystyrene to reduce weight. During the summer you should regularly inspect the underneath of pots for ant infestation.
If you want colour and scent then freesias in pots and as cut flowers are hard to beat in spring. Originating from South Africa they come in a wide range of colours and hybrids, they should be regularly watered when in growth and left to die down unwatered in the summer. Planted out they naturalise and come back year after year, but don’t put them in heavily irrigated areas as they will most likely rot.