Monavale is an unusual geological site - quite unlike the red ironstones of the surrounding hills (Meyrick Park, Sentosa, Avondale Ridge). It is made up of a calcium carbonate metamorphic parent rock which has a grey appearance, and breaks down into a fine grey powder. Tthe effect on our soils is to make them rather alkaline, unlike the more acid ironstones around us.
This has resulted in relatively unusual indigenous plant communities becoming established in the area that are found nowhere else in Harare. For example, distinctive orchids and aloes are found growing on bare rock surfaces - some of which are endemic to Monavale.
Natural ecosystems have the ability to support diverse insect, bird and small mammal communities, and an inbuilt mechanism to survive drought, fire, and the various other natural disasters. At the moment these 'genetic islands' are rapidly disappearing around Harare with the growth of the city and the cutting of trees around our margins for firewood and farming. With this in mind - it is essential to maintain as many pockets of undisturbed land as possible so as to ensure there is a genetic base which is large enough, and diverse enough, to maintain itself.
The increase in bird population on Monavale is almost certainly a result of the stands of indigenous trees still growing in our area.
Presently there are still the remnants of wild life here - night apes, mongoose, guinea fowl, one or two small buck living around the vlei margins and a snake population that is unfortunately rapidly disappearing.
The settlements growing on the hill have obviously changed this unique area and certainly the establishment of houses and gardens over the entire hill have made a huge dent in the natural habitat. Read More
This habitation has also increased the water input on the hill, and garden watering and domestic house run-off have enabled increase in the biomass. This has certainly added to the beauty of the hill but has undoubtedly jeopardized the survival of the natural ecosystem indigenous to the area.
Many of us have sections in our garden which we have left to nature, but even these become invaded by weeds, plants and trees that we have introduced over the last 80 years. Jacaranda, Deadly Nightshade, Lantana, Gums, Sisal and Prickly Pear being the most common.
The problems with these introduced plants can be seen as they rapidly begin to invade the natural bush, and as there is nothing within our natural system which controls their growth, they begin to out-compete the indigenous trees and grasses. A number of the trees (gums in particular) have an added problem in that they change the soil around them, which inhibits other plants from germinating and growing.
There has been an increased demand for firewood on the hill - both as a result of electricity power cuts and the increased human population on the hill. As both of these issues are likely to persist, it seems appropriate to consider the firewood management options for Monavale. This could include deliberate planting of trees for firewood as well as selective cutting of non-indigenous species.
For obvious reasons, the first trees that should be sacrificed are the Jacarandas, Firs and Gum trees that are invading natural parts of our gardens. All of these trees provide good fire wood.
However - when we begin cutting trees, it is imperative that we begin to plant replacements to ensure that the ecosystem does not become depleted.
There are a number of indigenous trees that can be planted - some of which grow fairly fast, and some of them more slowly. Both are needed. Unfortunately, Acacia gerrardii which is the dominant Acacia of the plant community seems to grow very slowly, whilst others which are less common (particularly Acacia polyacantha, and Acacia galpinii) are much faster growing. We are presently testing these for firewood, and though undoubtedly not as good as Jacaranda, they seem to suffice. A polyacantha can grow to a substantial tree within 6 years or so.
A number of large trees make up the predominate group of trees growing on Monavale. One of the ways to get to know the tree community in your garden is to start with the ones that you know or recognize already.
Acacia gerrardii / Grey haired acacia (there appears to be no specific Shona name)
This Acacia is indigeneous to Monavale, but not commonly found anywhere in the surrounding area. It has sickle shaped pods and flowers in white balls in October/November. In many gardens, the older gerrardii are beginning to die. Like all acacias, they are not particularly long lived trees, but because of their unique position in this tree community, is important to allow the young trees to survive - there are small gerrardii naturally springing back in areas which are not too disturbed.
Brachystegia boehmii / Prince of Wales Feather / Mufuti
Most residents of Monavale know these beautiful trees which are related to the Masasa. The new leaves flush slightly later than the Masasa, with the same beautiful array of autumnal colours. They are unfortunately relatively hard to grow from seed, and any young trees found growing in your gardens should be protected from fires and slashing.
Brachystegia speciformis / Masasa / Masasa
This tree needs no introduction, and is one of the most common trees of the Monavale ecosystem. Unfortunately, this too, is a hard tree to grow from seed. Young masasa can be found, both growing from seed, and springing out of damaged or roots of older trees, in untouched areas and once again, these need to be protected as much as possible. As most people on Monavale have noticed, the seed-making cycle of masasa is highly variable. Some years there is a literal explosion of popping pods that lasts for weeks, and in other years, there are almost none. Has any one any suggestions for this variation? The first orange flush of new leaves happens in early August - however, this too is a variable, with the first trees flushing as early as 10th of July this year.
Julbinardia globiflora / Monondo / Munondo
This tree is often mistaken for the Masasa, but can be told apart in various ways: The pods, though shaped like those of the Masasa, are a darker velvety brown and are carried above the crown of the tree. The leaves of the Monondo usually have 6 pairs of leaflets with the longest being the 3rd or 4th pair. The Masasa usually has 4 pairs of leaflets, with the terminal ones being the longest. The Monondo has creamy flowers from January to May, whilst the Masasa has less conspicuous flowers appearing as early as August.
Lucky Bean Trees: There are two species found on Monavale:
Erythrina abyssinica / Red hot poker tree / Mutiti
Both flower in late July/early August and can be told apart by the fact that the latissima has larger flowers and leaves (flower petals up to 5cm long and leaves up to 30cm in size). The pod on the latissima is similarly longer- 30 cm - whereas the pod of the abyssinica is about 10cm in length.
This is a beautiful tree with arching branches often making wonderful shapes. The leaves are covered in silvery velvet hairs and the tree produces small 4-winged fruit as early as January, which remain on the tree for many months.
The most common one is the Wild fig which grows all over Monavale. These trees are unique because of the ability of different individual trees to produce fruit at different times of the year. This asynchronous pattern results in an almost continual supply of fruit all the year round. This tree is an enormous attractant for birds, as anyone will have witnessed, when a wide variety of fruit eaters fill the trees as soon as they begin to bear. This tree has smallish leaves seldom longer than 8cm, and small fruits which grow along the branches.
Ficus capensis (sur) / Cape fig / Mukuyu
The Cape fig has much larger fruits (up to 4cm) which grow in heavy clusters on the trunk and lower main branches. Its leaves are also larger than those of the Wild fig (up to 23cm in length)
Lannea discolour / Live long / Mbvumbu
The Lannea is a common, if inconspicuous tree, found in the Monavale plant community. Male and female occur as separate trees. It has dark green simple leaves which appear white underneath due to a dense covering of whitish hairs. Small sweet smelling flowers appear on spikes at the ends of short branchlets in September, often before the leaves. It is one of the first trees to go yellow and drop its leaves at the end of the rainy season, and one of the last to re-flush, towards the end of September. The name Live Long comes from the fact that the poles when used as fencing standards strike and grow easily. A twine may be made from the stripped bark.
The trees that occur less frequently in the tree community are as follows:
Cassia singueana / Winter cassia / Muremberembe
This is a small rough barked tree often associated with termite mounds. It has striking deep yellow flowers which come out round June - September making a beautiful of flash of colour in dry winter gardens.
Azanza garckeana / Snot apple / Mutohwe
There are a few snot apples growing around Monavale. This tree is also known as African chewing gum - if any one has ever chewed the fruit you will know why! The leaves are large and 3-5 lobed, stiff and leathery to the touch and have hairs on both upper and lower surface.
This is a relatively rare tree on the hill. There is an example of this outside Jon and Laurie's gate in Ernies lane. It has a greeny-yellow shiny bark and exudes a pale gum if damaged. This may be one of the trees that provides gum for the bush baby population living on the hill. It easy to recognize with its spine-tipped branchlets and tri-foliate scalloped leaves. In winter it is covered with small pinkish-red fruits. These germinate easily and are easy to start in pots. Apparently the larva of the beetle Diamphidia which feeds exclusively on the leaves of this tree are used by bushmen to make their arrow poison.
Cussonia natalensis / Simple-leaved cabbage tree / Mufenje, mutobvi
A number of these cabbage trees are present in this plant community. They are easily recognized by the single trunk and the rounded crown which looks, only slightly, like a cabbage. The leaves are large with 5 lobes and begin falling attacked to long stems around June.
This is a lovely tree which is most conspicuous during winter when its fiery-orange leaves still hold on when most of the other trees have dropped their canopy. It has small (2 cm) round pale yellow fruits which stay on the tree, often until the next years fruits appear.
Rhus lancea / Willow rhus / Mutepe
This is a smallish (up to 8 m) evergreen tree with long slender tri-foliate leaves which hang down making it look a little like the English willow. When crushed, the leaves of all rhus trees give off a subtle fragrance.
Rhus tenuinervis / Commiphora rhus / Mufokosiana
A second rhus also grows on Monavale, the only similarity to the first being the tri-foliate leaves, though these are larger and well rounded. Leaves give off the same fragrance when crushed.
A few examples of this well known tree are found on rocky outcrops on Monavale. It is an important medicine tree, and will often be found to have strips of bark cut out which have been used for various cures (from malaria, and headaches to gonorrhoea) The name, Ptero-carpus describes the seeds (ptero - winged, carpus-seed) and has the familiar circular pod which has dense harsh bristles growing in the centre. It has one of the best known and most used woods in southern Africa, being used for furniture and parquet flooring. It has yellow pea -shaped flowers which appear on branched sprays in August - December.
This tree carries the well known monkey orange fruit which comes in a spherical woody cover. Its leaves can be recognized by the formation of 3 - 5 veins which start at the base of the leaf.
Smaller trees and shrubs that make up the growing in the understory are as follows:
Diospyros lycioides / Red star apple / Mushumadombo
This is more of a many stemmed shrub than a tree, and is noticeable as being one of the most persistent trees to hold onto its dark grey-green leaves during the dry winter months. It flowers in September - December with tiny sweetly scented creamy white flowers.
Grewia flavescens / Donkeyberry / Mubhununu
This is a many stemmed shrub with a tendency to scramble. It has narrow grey/green leaves and its trunk and branches are square with fluted edges. Yellow flowers appear around December, and the small 2 - 4 lobed fruit provide excellent food for birds.
Grewia monticola / Grey grewia / Mubura
This is a shrub or small tree with drooping branchlets covered with creamy or rusty woolly hairs. The leaves are much wider than those of the of the Donkeyberry and tend to be a brighter green above and white below. Yellow flowers in October turn to single or deeply 2-lobed fruits.
This small tree seldom grows above 7 m. The most noticeable thing about this tree is its sweetly scented yellow flowers which appear in early September before the young coppery leaves and only last for a day or two. The fruit are 2 - 4 separate carpels which turn cherry red between October and January.
Pavetta gardeniifolia / Common brides bush / Mufuramhembwe
This is a shrub or small tree p to 4 m in height. Creamy white, heavily scented flowers appear between early November and January. They grow prodigiously on Monavale, seeming to shoot from underground roots rather than seeds. It is easily identified by the dark bacterial nodules insides the leaves which can be seen when holding the leaves up to the sun.
Steganotaenia araliacea / Carrot tree / Musvodzambudzi
This is a small sparsely branched tree with leaves crowded at the end of branches. All parts of the tree small strongly of carrots.
Acacia gerrardii Grey haired acacia ??
Azanza garckeana Snot apple Mutohwe
Brachystegia boehmii Prince of Wales Feather Pfute