Temperatures will be quite high this month and many plants will have gone over. Luckily, we can grow wonderful tropical trees to help us get through this period. South Africa gave us Carissa macrocarpa and Plumbago auriculata. The latter can cover unsightly fences or walls in no time. It propagates itself by sending out runners, and also seeds, which have a habit of sticking to your clothes and then germinate where they drop. Carissa makes a good defensive barrier against would-be intruders, as the glossy green leaves, contrasting so well with the heavily perfumed white flowers, have very thick thorns tucked in underneath the stems. Tall South African summer bulbs like the blue agapanthus (Agapanthus africanus) are flowering now, as well as in white varieties. Newer smaller plants with blue and white striped flowers are being introduced all the time. They are sometimes called ‘iffy’ plants as they don’t always produce flowers. Crowding them together in a pot doesn’t help either, but a feed with a high potassium fertiliser in the autumn may aid flower production.
Albizia julibrissin known as the ‘Persian Silk Tree’ or the ‘Chinese Silk Tree’ because of its lovely tasselled ‘flowers’, came from tropical or sub-tropical areas. Drought tolerant and able to survive strong winds, Albizia can grow just as easily in sandy free-draining soil as in clay and is a most suitable tree for coastal gardens. The sweetly-scented flowers appear in mid-summer. They have no petals but clusters of perhaps 10 or more long stamens resembling silk threads. They are generally pink or pink and white and are extremely attractive to bees, moths, and butterflies. The light sensitive foliage, which closes up at night has around twenty small pinnate leaflets.
At this time of year Delonix regia, known otherwise as the ‘Flame of the Forest’ tree, because the crown looks like it is on fire. These trees can tolerate drought or grow in salty conditions, so again are very suitable in more humid gardens although they can grow quite tall. Originally from Madagascar this many branched tree forms an umbrella shape which is quite pleasing to the eye. Although it is fast growing it may take up to ten years before any flowers appear. It is considered one of the most beautiful trees in the world!
A large shrub from the Bignoniaceae Family is Tecoma capensis, (which used to be known as Tecomaria). It can put on enormous growth each season and needs severe pruning after flowering or it will take over your garden. Commonly known as the Cape Honeysuckle, the flowers are usually bright orange or perhaps yellow.
Tecoma stans will be thrusting skywards and showing off its brilliant yellow flowers amongst bright-green leaves. Also belonging to the huge Bignoniaceae family it is a native of tropical America, but grows extremely well in many other parts of the world where it is sometimes known as ‘Trumpet Bush’, ‘Ginger Thomas’, ‘Yellow Bells’ or ‘Yellow Elder’. There is a resemblance in the leaf structure to the common elder that you may have grown in Northern Europe, whilst the glorious bell-shaped flowers contrast so well with our bright blue skies. Feed this lovely tree with an all-round fertiliser in spring. Campsis radicans originally came from Virginia in the United States. This ‘Trumpet Creeper’ or ‘Hummingbird Vine’ is much beloved by little birds, which dip their beaks right into the flowers. This is a hardy vine and rampant climber, so be careful where you grow it as it can grow to quite a height in a very short while.
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