TREE LIFE

JANUARY 1988

 

1st January : Happy New Year 

Tuesday, 5th January: Botanic Garden walk.   Meet in the Car Park at 4.45 for 5 p.m.

Sunday 17th January  :   We have arranged an outing to Mrs Fie Verwoerd’s Farm/Riding School at Wingate. This is delightful countryside fringing on the Criston Bank hills.  There is some woodland, a stream with riverine vegetation, a dam and a roof to shelter under should it rain. No bus arranged on this occasion so just arrange lifts etc., to meet there at l0.00 am.

Saturday, 23rd January: Join Meg Coates Palgrave for a most informative, yet relaxing walk in the Mukuvisi woodlands which, from being parched and burnt out so recently will be looking lush and green following the rains. Meet at 3.30 pm at Paget Road/Inyanga Crescent gate.

Tuesday. 2nd Februay: Botanic Garden Walk at 4.45 for 5 pm.

Saturday, 27th February: Mukuvisi Woodlands Outing. 3.30 pm; Paget Road/Inyanga Crescent.

 

MATABELELAND CALENDAR.

On Sunday, January 10th we go to Mr. McNeilage’s residence, Kirton-Estate near Heany Junction.  Meet at Ascot Centre car-Park, at 8.30 am but arrange lifts beforehand as cars should not be left.

MATABELELAND NOTES

Commiphora schimperi. Photo: Bart Wursten. Source: Flora of Zimbabwe

Commiphora schimperi. Photo: Bart Wursten. Source: Flora of Zimbabwe

On Sunday, December 6th we went to the Blakes House, Glenville. The area has large Granite Bars in the stream and much decomposed along the banks, and has been cut agood deal, so much of what we saw was small or stunted, but we identified some 55 species, many in fruit or flower, also some fine wild flowers. 3 interesting papers were read, two on Acacia nigrscens and Commiphora schimperi by Nell Baxendale and one by Betty Blake on Ficus abutifolia not often seen so near Bulawayo.

There were six  Acacia species, A.gerrardii ,flowering   A.karroo, A.nigrescens in full leaf already, A.nilotica, A.polyacantha, not often seen near here, A.rehmanniana, flowering; some young Azanza garckeana but still showing the midrib gland, Bolussanthus speciosus, still flowering,  Clerodendrum myricoides the Blue Cats whisker, in full and most attractive flower, three Combretum, C.apiculatum in very young leaf, C.hereroense both the softly-hairy and the shiny leaved, many small Leadwood, C.imberbe, four Commiphora, Commiphcra africana soft and hairy leaves, C.molle, some with very glossy new leaves C.schimperi, the shiny one, and C.pyracanthoides indistinctive fruit, Diospyros lycioides, a very fine Erythrina latissima, leave on the small side but a good bole, two figs, Ficus abutifolia, F.glumosa, two Grewia, G.flavescens, G.monticola, one Kirkia acuminata, a few young Lannea discolour, Lonchocarpus capassa, many finely flowering  Munchalea sericea, Ozoroa insignis subsp reticulata in flower, Pouzolzia mixta flowering, Rhus lancea, R. pyroides, R.leptodictya, a few marula Sclerocarya birrea, several surprising Terminalia randii on the decomposed, T.sericea, some with very silky leaves, Turraea nilotica, Vangueria infausta, fruiting and some young Ziziphus mucronata.

-C. SYKES.

 

WILD ANIMALS AND BROWSE TREES

This is a subject on which I claim no expertise, so it is probably an excellent one on which to launch a short thesis.   All letters of outrage should be addressed to the Chairman. He it was, who invited me to write it.

In the course of camping expeditions, even those in which the dietary preferences of fish may be of more immediate concern than the feeding habits of game, one‘s joy in ones surroundings is enhanced immeasurably by the presence of wild animals and birds.  The over-riding reason for resisting the temptation to give voice to frustration when the fish are uncooperative, is that it would be unforgivable  to rupture the atmosphere of serenity in which birds accept one’s intrusion or in which a shy antelope, or squirrel, or leguaan, or even a croc, night suddenly materialize as if a magician had waved a wand. Such expeditions, and others more specifically planned for game-viewing, leave one with an ever-mounting interest in both the habitat and the habits of wild life. If, for example, one has yearning to see giraffe in numbers, a trip to Hwangwe National Park can be most rewarding, but a journey to Hwange would be disappointing.   Our giraffes are in their element on the Kalahari sandveld of the Hwange National Park, among their beloved Acacia eriloba trees (previously called – far more appropriately to the animal lover – A.giraffee) and show no desire to migrate to the Mana Pools environment.

Acacia eriloba. Photo: Bart Wursten. Source: Flora of Zimbabwe

Acacia eriloba. Photo: Bart Wursten. Source: Flora of Zimbabwe

In another context, one tends to find that while Brachystegia  tree species are not highly prized as preferential  browse, at least in some areas, many plants and grasses associated with Brachystegia woodlands are well utilized by browsers and grazers respectively.

But these are random thoughts, merely to make the point that the study of browse preferences can add immensely to the fascination of trees, as well as of animals.

I would venture the opinion that among the most utilized browse plants, judging by the frequency with which they are singled out for mention in authoritative works on the subject, are the following 30 to 35, well known to us.

  1. a) Leguminous plants as a whole — their high protein value derived, possibly, from nitrogen fixation by root nodule bacteria – and, within that family the genus Acacia, with tortilis and A.karroo getting high marks. Also the legumes Bauhinia thonningii, Burkea africana, Colophospermum mopane, Dalbergia melanoxylon, Dichrostachys cineria, Lonchocarpus capassa, Pterocarpus rotundifolia, Schotia brachypetela.
  2. b) COMBRETACEAE with, prominent amongst them – Combretum apiculatum, C.collinum, C.hereroense, C.molle, C.zehyeri.
  1. Other : Bequeratiodendron maqalismontanum, Bridelia mollis, Capparis tomentosa, Diplorynchus condyloccarpon, Euclea divinarum, Grewia flavescens, Kirkia acuminata, Maytenus heterochylla, Mimusops seyheri, Pseudolachnostylis maprouniefolia, Strychnos spinosa, Boscia spp., Diospyros spp, Ficus spp. – fruit in the main but leaf browse also to some extent, Lannea spp, specially the fruit of the ground hugging L.edulis, Syzygium cordatum, Terminalia sericea, Ziziphus mucronata. 

This list could easily be doubled or trebled. My selection has been a trifle arbitrary, but not blindly so. An essay in greater depth would take into account the fact that one researcher in the 70’s recorded 87 browse plants (and 42 grasses and 36 herbs) on which elephants live; that studies in East Africa indicated that some 200 species of plant were browsed by Black Rhino; that in the Kruger National Park l48 species have been associated with kudu as browse; that eland are reputed to eat just about any plant under the sun, depending on availability and seasonal needs. Smithers, 1983).

A generalization which is fairly widely accepted I think, is that, just as termite mounds are the richest source of plant variety in the veld, so, too, do animals prefer to browse on the plants thereon, presumably because of their more highly mineralised content.

Incidentally animals which are predominantly browsers do, occasionally, graze, and “grazers” are known to browse some of the time. The little steenbok nibbles leaves and grasses with equal enthusiasm, the proportion varying with the habitat.   The grysbok is said to be similarly inclined.  Impala are also partial to both browse and graze-type vegetation, and as shown above, elephants also believe in variety.  Subject to these observations, animals which are categorized as predominantly browsers include Black Rhino, giraffe, duiker klipspringer, kudu, nyala, bushbuck, eland.

The grazers (again remembering a tendency by some of them, quite frequently do browse) include zebra, blue wildebeeet, tsessebe, oribi, roan antelope, sable antelope, gemsbok, buffalo, reedbuck, waterbuok, hartebeeet, square-lipped rhino, hippo and warthog.

On the 10th November the Chairman and Maureen, and I, travelled to Mr John Becks‘ farm “Chelvey” by invitation, to chat to him and to other members of the Bindura Wild Life Society about browse vegetation. The members of the Society appear to be drawn from the Bindura, Matepatepa and Shamva areas. It is chaired by Mr Ian Taylor of Imsingisi Farm.  Some of the numbers have stocked, or are in the process of stocking, game procured from the Dept. of National Parks and Wildlife Management.  In John’s case, wildebeest and impala have been introduced to supplement the kudu and sable that are resident in the area.

John and Wendy made us feel immediately at home and we were most cordially welcomed to the gathering also by Ian (in the chair), and by other members of the group who arrived for the meeting.

We found the chat stimulating – as we hope our hosts did also – and we would have liked time to explore the area more thoroughly. We had time to ‘take in only 48 trees and shrub species. These we saw in the boma (a spacious and well wooded enclosure), and in the course of two foot patrols along a 150 metre gwasha fringe, and while travelling by truck along a track bisecting the game area.

Almost 70% of the trees were browse trees, as indicated * below

Dichrostachys cineria. Photo: Bart Wursten. Source: Flora of Zimbabwe

Dichrostachys cineria. Photo: Bart Wursten. Source: Flora of Zimbabwe

Acacia amythethophlla * ,  Julbernardia globiflora,  A. polyecantha *,  Lannea discolour*, A.rehmanniana *,   L. edulis*,   A. sieberana *,  Maytenus heterophylla *,   Acokenthera oppositifolia *,   M. senegaleneis *,  Bauhinia petersiana *,   Myrica serrata,   B. thomingii * Peltophorum africanum *,  Brachyetagia boehmii,  Pericopsis angolensis *,  B.spiciformis, Protea gaguedi (emphasis on birds) *,  * Capparis tomentoea *,  Pseudolachnostylis maprounifolia *,   Cassia singueana *,  Pterocorpus angolensis *,  Cathe edulis, Pterolobium stellatum,   Celtis africana *,  Rhus longipes,   Combretum erythrophyllum *, R. quartiniana,  C.fragrens *,   Salix subserrata *,  C. hereroense  *,  Securidaca longepedunculata *,   C. molle *,  Securinega  virosa *,  * Dichrostachys cineria *, Terminalia sericea *,   Diospyros lycioides *,   T.stenostachya *,  Diplorhynchus condylocarpon *,   Vangueriopsis lanciflora (emphasis on birds),  Dombeya rotundifolia *, Ekebergia capenais *,   Ximenia caffra *,   Euclea divinorum * ,  Ziziphus mucronata*,  Faurea speciosa *, Ficus sur

The Ekebergia trees were outstanding; without doubt the most imposing of all in the riverine area, and within the boma was the most splendid Ximenia caffra imaginable, some 25 feet tall, and full of almost mature fruit.  Another fine specimen of the same tree was growing within the inner stockade.  The poison-bush Acokanthera, was sparse of leaf and very dry, and was taken to the Herbarium for identification. We were struck by the fact that there was no sign whatsoever of browse utilization of the muwanga Pericopsis angolensis. 

Note was taken at our meeting of the fact that some fruit pods are toxic when unripe, some bark, some sap, some roots, are used as poisons by man; even some seemingly innocuous plants are said to employ a defensive mechanism (e.g. when in danger of being over-browsed) whereby repellent chemical substances are produced or increased in foliage or elsewhere.  I amsending the checklist to our hosts, however, it was suggested that if one allowed oneself to be overawed by all these “ifs” and “buts” and possible hazards, one might as well confine oneself to keeping budgies, a remark, I hasten to say, not meant to be derogatory to budgie lovers.   It seemed fair to add that the list of the few plants we had time to look at, included a very satisfactory percentage that were utilized at certain times of the year, and that even among those, not symbolized by * there were probably some browseable ones.

-R. W. Petheram

 

BRIAN BEST REPORTS THE COLLECTION OF AN UNUSUAL MOSS

During the visit of the Tree Society to Seoul Drift Farm on August 16 last, a moss was collected which proved to be not only the first record for Zimbabwe but also for Africa as a whole.

We thought you would be interested in this, so here are the details :

Name : Alonina brevirostria (Hook. & G1-ev. ) Kindb.

Previously only known from the northern hemisphere (Europe,  Asia and North America).

Habitat  :  On soil of a large termitarium, bare of trees or shrubs.  Soil very fine and almost white.

This moss is normally a pioneer of bars,  limey silt, especially road banks and river bluffs.

In Zimbabwe in December we not only celebrate Christmas, but we also observe Tree Planting Day. And this year the Prime Minister has taken the lead in advocating planting indigenous trees. This is a very welcome development.

We are, however, concerned that the demand for indigenous tree seedlings for Tree Planting Day may well exceed those available. This is an area in which the Tree Society can materially assist and which members can all do so at their own level.  While out in the bush, many of us collect seed and/or cuttings and/or plants.   We propose to encourage and co-ordinate seed collecting and seedling growing so that there will be sufficient indigenous trees available in the future.

There will be more details over the next couple of months but in the meantime here are two articles, one unearthed from the past but still pertinent by Trevor Gordon and the other based on a talk Meg Coates Palgrave gave at an Education Department Tree Growing and Tree Care Workshop.

METHODS OF PROPAGATING INDIGENOUS TREES AND SHRUBS – THEIR ADVANTAGES ANDDISADVANTAGES

OPEN BEDS

These beds in open ground should be dug up to 12 to 20 cm (6 to 8 inches) deep and then raked to an even tilthe.  Width and length of beds depend on amount of seed to be sewn and personal preferences. The site of the beds should be in reasonably good soil and well drained.  Beds should not be sited under trees in the rainy season as drip from the trees will cause damage.

Seeds should be planted in drills 50 to 80 cm (2 to 3 inches) apart and the beds then covered with a mulch of grass. The grass should be cut short 12 to 13 cm (6 inches) without any seed heads. Thatching grass can be used so as to lie right across the width of the beds.  Again care must be taken not to use grass in seed or to cut the seed heads off.

Beds should be kept damp and grass mulch gradually thinned out as seeds start to germinate. The grass need not be taken away completely but enough to allow the seedlings to emerge into the light. This also helps to reduce the amount of water needed.

Advantages:  Low initial cost, large quantities of seed can be sewn in a short time.

Disadvantages:  As germination is almost always erratic removal of mulch evenly is difficult. Young seedlings have to be transplanted causing disturbance if not handled very carefully.  In the case of most leguminous plants which send down a tap root damage could result with loss of seedlings.

Wooden Flats

These can be old peach trays for small seeds or larger and deeper boxes made up for bigger seeds. Boxes should have slatted bottoms and a thin layer of grass put in to prevent soil from dropping out and for drainage.  If boxes are kept in shade under trees or in a shade house they need not be covered, but here again in rainy weather they should be given some protection.

Advantages :  Closer watch can be kept on the germinating seeds and seedlings can be pricked out sooner into tins or pots. Pests can be controlled.

Disadvantages :  More time and some expense required on boxes and again need to transplant seedlings to tins or pots causing a certain amount of disturbance.

POLYTHENE TUBES, JAM TINS OR OIL TINS

This is by far the most satisfactory method although more time consuming.

The tins can usually be had for nothing as for a small price. The polythene tubes can either be bought made up (in various sizes) or the roll can be bought and cut to size which makes the tubes slightly cheaper. The tins and/or tubes must be perforated at the bottom for drainage.

Advantages :  This method is specially recommended far large seeds as the seedlings remain undisturbed and can with slow growing plants remain in the original containers for a year or more after germination.  Small or fine seeds can be pricked out much earlier with very little disturbance.

Disadvantages :  More time and attention required at sowing.

Soils Open beds and good well-drained soil.

Wooden flats, tins or polythene tubes. A mixture of half good garden soil and of coarse sand and half compost or leaf mould. This mixture has given good results for the start.  For the final potting, if plants at to be kept for 2 years or more, a mixture of it garden soil and compost. Final potting is mentioned because seedlings must eventually be put into large tins or polythene tubes to allow for good root growth.

Sowing.  No seed must be planted deeper than its own thickness. Fine seed, such as figs, must be sprinkled on top of the soil or mixed with a little sand and then sprinkled.  Seeds with hard casings may be soaked for a day or so or the hard skin cut slightly with a knife.

Best results are obtained with absolutely fresh seed.

Water :  Water sparingly, enough to keep the soil damp. Indigenous plants seem to be more prone to damping off than cultivated ones.

Shading :   Some form of shade is necessary for the boxes, tins or tubes. This can be under trees (care must be taken in heavy rain), under an open-sided grass shelter or a shelter made from polythene sheets. Seedlings, as they germinate have to be moved gradually from full shade to dappled shade and eventually to full sun to harden off. This depends entirely on the growth of the seedlings.

Final Potting : This is only mentioned if the plants as to be held until they are one metre high before being transplanted to where they are to stay.

The large tins or pots or tubes must be put onto a content floor or onto old polythene bags or sheets. If this is not done the roots of the plants will penetrate the ground and take root causing damage at transplanting time or the roots of surrounding trees will invade the containers with the same results.

Time of Sowing :  The best time is Spring and during the summer months as temperatures and humidity are right for this type o sowing.

Seeds can however be germinated with an inexpensive cardboard carton measuring roughly 60 x 45 cm (210 x 18 inches). But of course this can only handle small amounts of seed. The tins or tubes with the seed are placed at the bottom of the carton leaving space enough to put a glass of water in the middle and directly under the electric bulb. A 40 or 60 watt lamp can be used. If a thermometer is placed in the box a steady temperature can be maintained of about 25 to 29°C. The water in the glass should be topped up whenever necessary.  As soon as the seeds germinate they should be removed from the box but still kept in the room but placed next to a source of light such as a window.  When the seedlings are big enough they may be taken outside but still protected from wind, sun and cold.

Propagation by Truncheon :  Most trees with a thick bard, if when cut exude a fair amount of sap will usually grow from truncheons.  It is advisable to let the truncheons lie in the shade for a day or two or until all exudate has dried before planting. Unless this done the chances are that the truncheon will rot at the base.  The best time to take truncheons is when the tree is dormant but this is not a hard and fast rule.  It is a good rule to put a little course sand at the base of the truncheon when planting out.

Collection of Seeds

Seeds should be collected as soon as they are ripe. Seeds should only be collected into paper bags never polythene. All types of berries should have the pulp removed and the seeds dried before planting.  It is well worth the trouble to keep a note of the locality and the date of when planted and germinated.  So little information is available on this subject that any success or difficulties experienced plus the methods used will be of great value.

These notes which have been compiled are the writer‘s personal experience will not

guarantee success but are given as e guide to the problems confronting the would-be indigenous tree propagator.  The list below are some of the trees and shrubs that have been grown with approximate times of germination. The first list is of three of the impossibles. Hope someone can come up with an answer.

The Impossibles :

Elephantorrhiza goetze                 No germination so far

Monotes glaber                               No germination so far

Strychnos innocua                         No germination so for

Some Difficult Ones

Ximenia caffra                               germinate readily dies off in six months to two years.

Swartzia madagascariensis       germinates readily and then dies off or is very slow.

60 to 18 cm in 1.5 years.

Ochna pulchra                               seeds lose viability soon. Should be planted within a week of                                                                        collection.

Ilex mitis                                         seeds collected and kept for from 2 weeks to 2 months – no                                                                            germination. Seeds collected from tree and planted the next day –                                                              germination 100%

Trees with few problems :

Definition of symbols : LT – large tree;   MT – medium tree;   T – small tree ;  S  shrub;  EG – evergreen;   D – deciduas

Acacia species                               germination 7 to 40 days, mostly LT, MT or T D. –

Acocanthers oppositifolia          EGS. Germination 2 to 6 weeks fast growing, attractive in flower.

Adonsonia digitata                      LTD. Slow erratic germination, probably requires additional heat 4                                                           to 8 weeks.

Afzelia quenzansis                       LTD. Germinatee 7 to 21′ days. Seeds are viable upto 10 years old.

Antidesma venosum                    EGS. Germination 10 to” 2) days. Fruit edible.

Azanza garckeana                       Germination 21 to GU ‘days.

Baphis massaiensis                      SD or TD. Germination 10 to 30 days. Very showy in flower.

Bauhinia galpinii                         Germination 7 to, 21 days  S

Bauhinia tomentosa                    Germination 7 to 15 days.   SD

Bolusanthus speciosus                MTD. Germination 6 to 25 days.  Vary attractive in f                                                                                       flower.

Brachystegia species                   LT or MT or T, EG, or D. Germination 10 to 40 days. slow growing

Calodendrumcapense                  MTEG or MTD  Germination 14 to 90 days atractive in flower

Cassia abbreviata                        MTD. Germination 17 to 90 days. Rather difficult, slow Growing, s                                                              seeds parasitized

Celtis africana                              LTD  Germination 15 to 35 days. Quite fast growing.

Combretum species                     The wingson the seedssholdberemoved for faster germination.                                                                     Germination very variable in the species, usually 3 to 30 days.

Cussonia species                           Seed or truncheon.  Germination 15 to 35 days

Dichrostachys  cinerea                S or STD Germination 14 to 25 days

Euclea natalensis_                        EGS or EGT.  Germination 15 to 20 days

Erythrina species                         Germination 7 to 15 days also by truncheonm

Euphorbia species                        Seedor truncheon.  Germinationvariable 5 to 30 days

Ficus species                                  Seed or truncheon. Germination 15 to 30 days

Kigelia africana                            LT.  Germination 12 to 25 days

Lannes discolour                           MTD orLTD.  Seeds or truncheons.  Germination 10 to 30 days

Lonchocarpus capassa                 MTD.  MTD.  Seeds, germination 7to 21 days

Markharmia acuminate              S or STD.  Seeds germination 10to 15 days.

Musssaenda arcuata                    EGS.  Seeds, germination 7to 20 days

Ochna pulchra                               STD.  Seeds,germination 15 to40 days.

Onchna  spinosa                            S or STD seeds, germination 12 to25 days

Peltophorum africanum               S or ST.  Seeds, germination 10to 30 days

Phoenix reclinata                          Seeds,germination 25 to 35 days

Raffia farinifera                            Seeds, germination 6 to 14 months

Protes species                                  No luck with seeds so far

Pterocarpus species                       Seeds of truncheons.  Germination in species very variable, 20 to                                                                40days

Securidaca longipedunculata      Sor STD.   Seeds germination difficult 20 to 30 days

Sterculia species                              Seeds or truncheons. Seeds of Sterculia africana viable for 10 years

Stereospermum kunthianum        MTD.  Seeds germination 7 to 21 days

Strychnos species                            S or STD.  Seeds, germination very difficult, 21 to 40 days

Syzygium species                            Seeds, germination 7 to 20days

Trichelia emetica                            Seeds, germination10 to 20 days

Uapaca species                               Seeds, germination difficult 20 to 30 days

Zyziphus species                            Seeds, germination 14 to 30 days

 

GROWING TREES INDIGENOUS TO ZIMBABWE

GROWING TREES FROM SEED

The seed should be fully ripe – This can be assessed in several ways :

  1. a) some pods and fruits fall to the ground
  2. b) other pods split when ripe;
  3. c) fleshy fruits have developed their full colour.

If uncertain whether a pod or fruit is ripe, pick it and if it comes away easily in the hand then it is probably ripe.

The seed should not be damaged by insects.  This can often be seen by a conspicuous mark on the outside of the pod and become obvious when the pod is opened and, the remains of the seed is all that is found.

The flower must have been fertilised and the seed must be viable.  Seed sometimes appear to have firmed but has not actually been fertilised.  One way this can be tested is to put then in water.  If they sink and eventually swell they are probably viable and also undamaged by insects. If they do not swell within a week they will probably never germinate.

Seed should be soon as fresh as possible.  If collected in June or July perhaps it would be better to keep them until September before sowing.  The soft seeds probably all ripen during summer and can and should be germinated immedidately.

Hard seeds can be kept.  To store seeds ensure that they are :

  1. a) clean and dry (if necessary de-pulp, wash and dry or de-pod
  2. b) store in a cool, dry place;
  3. c) not in an airtight container (an envelope or paper bag is preferable to a bottle or plastic bag)
  4. d) lightly dusted with a fungicide.

(vi) Preparation or Pre-treatment of Seed :

  1. a) fleshy or soft seeds should have the flesh removed and be sown immediately. They probably do not require any pre-treatment
  2. b) Hard node can be scarified. Scarification means opening up the hard outside coat or testa so that water can penetrate. This can be done by pricking with needle, nicking with a blade or knife or filing on a grinding wheel or with a file or abrasive paper. Although this does increase the danger of fungal attack, it definitely enhances and hastens germination. Scarificatim should be done on the shoulder of the seed away from the microphyl.
  3. c) Soaking neck in water can also enhance germination. Take the water off the boil and pour it over the seed and leave them overnight (not more than 24 hours). Or else put them in warm water (hot enough to just be able to put your finger in) and leave overnight or until they start swelling. This can use he done after the seed has been scarified.
  4. d) Trere is another method which was suggested to me recently. Soak the seed for a period, say 24 hours, starting with warm water, let it dry out for the same period, soak it again and then sow. This probably stimulates what happens in nature;  there is a good rain and everything including the seed gets thoroughly wet and then there is no rain again for a while, followed by a further rain.

Soaking seed in a weak solution of sulphuric acid far 10 minutes and then washing immediately.  This is a useful method for a large number of hard seeds.

  1. e) Burning seeds sometimes is necessary for them to germinate. This can be done by making a small fire similar to the heat of a veld fire.
  2. f) Some seeds often do not respond to any of the previously mentioned treatments and need to pass through an animal or bird before they germinate. Collect seed from bird and animal droppings.
  3. g) A recent suggestion to reduce the danger of fungal attack is to put the seed into a weak solution of Jik or Javel for a few minutes before trying to germinate.

GERMINATION

Most seeds need moisture and warmth to germinate. They should be kept damp but not too wet and certainly not water logged.

Many seeds germinate well in the open particularly during warm weather. Warmth can be increased by germinating under grass or plastic or even better in a frame or greenhouse. All these methods are used to enhance the heat curing the day and keep the temperature up at night.  It is not necessary to put needs into soil to start them germinating. They can be put an damp sand in a kaylite or plastic box which can be kept covered with glass or plastic. This ensures that the sand does not dry out.

The sand should first be sterilized by baking it in an oven or pouring boiling water over it several times. Large seed can he put on the ground covered with plastic and a sack which should be kept damp or even put in a tray in the middle of a compost heap which is hot and maintains an even temperature and has the advantage of supplying heat from underneath.  If seed is put straight into the soil it should be in individual containers and covered with soil or sand to a depth equal to the seed’s diameter. If planting an already germinating seed hardly cover the seed.  Under natural conditions in  the veld I doubt if the seed buries itself.

Germination can take from a few days to several months, but after a year or 18 months germination is unlikely to occur.

GROWING TREES FROM CUTTINGS AND TRUNCHEONS

  1. a) Root cuttings can be taken from growing roots. These should be about 4-6 cm long and as thick as a pencil. They are laid flat in individual pots and covered with about 2 cm of a mixture of soil and sand. Like germinating seed they need moisture end warmth. They should be left undisturbed until well established and this is long after a stem appears.

If plants sucker when the roots are disturbed they will probably respond to propagation by root cuttings.

  1. b) Stem or hardwood cutting; are best taken in Spring just before the new growing starts. Cut a piece of the previous year‘s growth about 15 to 13 cm long and l to 2 cm in diameter, take off the leaves and put them into a mixture of sand and soil so that no more than about 5 cm is showing with a leaf-bud near the tip.
  2. c) Truncheons can be a very successful method of propagation. They consist of a piece of branch or stem .5 to 2 m long. Place them directly in the position where they are expected to grow preferably on some sand at the bottom of the hole. Fence posts placed in the ground often grow giving rise to a living fence and demonstrate this very well.
  3. d) shallowly rooted plants are often found particularly on rocks and growing forests and can be successfully transplanted.
  4. e) Seedlings can be collected from damp soil and transplanted making sure that the root system in undamaged.

GENERAL

  1. a) Containers – plastic bags or waxed cartons are preferable to tins as they can be torn open easily and the tree can be transplanted without disturbing the roots. Milk, sugar and mealie meal packets with holes punched or poked through the bottom are all suitable. A few small stones at the bottom covered with large dry leaves to prevent the soil being washed out, also assist with drainage. Once the seedling or cutting is established in a small bag, it is desirable to move it to a larger one at least once or twice. The last bag being the size of a l0 kg mealie meal bag.

By the time tin tree has become established in a bag that size, it will be ready to plant into the open. If a tree is to survive it is essential that it becomes well established before it is planted into a woodlot and people should be urged not to be impatient and plant their trees out too young unless they can be cared for.  Obviously if the tree is to be planted  in a garden where it will be watered and cared for it is not necessary for it to be quite so big.

  1. b) Soil – a general potting soil consisting of compost sand and soil should be used.  If it is possible to use some soil from the area in which the parent tree grows this is desirable particularly for cuttings and seedlings, but it is probably not a good idea to sow seed in soil taken from under the parent tree as sometimes trees inhibit germination of their seed immediately  beneath them.
  2. a) Nursery – it is advisable to keep the seedlings in their containers on a cement floor or some other impervious surface so roots tend to find their way through the holes in the bottom of the bags and make their way down  into the soil and very often if that root is damaged or broken the plant dies.
  3. d) Planting times – the best time to plant trees out is in the middle of a rainy season when the soil is thoroughly wet and there is more rain to come, probably early January.
  4. a) Holes – a good hole 1 to 1.5m deep filled with well rotted compost mixed with superphosphate gives the tree a good start in the ground.
  5. f) Problems — having grown well over 100 species many of which I germinated myself, 1 have had tremendous pleasure from growing indigenous trees, but I and other growers have had our disappointments and here I would like to mention some of the problems and difficulties.

 

(1) vegetable or flower seed bought in a shop has almost certainly been tried and tested; the seed from the indigenous trees will more or less have been collected at random. Some seed seems to germinate easily and grow vigorously while for no apparent reason other seed,  even from the some tree, given identical treatment having germinated, never seem to get away.

(ii) Some species such as Uapaca kirkiena, Muzhenje,  Mahobohobo or Ximenia caffra Vutengeni, Umthunduluks or Ochna pulchra, Mutninu, Umyelehyele  germinate easily but die off in the first two years and there are a number of very common species such as the Manotes, meheve, Inyunye which we have not succeeded in germinating.

(iii) Many of our indigenous trees belong to the legume or pea family and therefore have a very long tap root. This is one of the reasons for putting them into bigger bags so that the tap root does not go round  and round inside a little one. Indigenous trees have a reputation for being very slow growing. They are probably developing the root system before suddenly putting on growth above ground.

(iv) Low veld species, often grow well at higher altitudes, probably because there is a higher rainfall. They should, however, be protected from frost during the early stages. Water plays a very significant part in the tree’s growth.  If it is possible to start metering the trees during September once the weather has warmed up and then water again during any prolonged dry spell until April, this gives the trees a 6 month growing period and they respond very well.

ENCOURAGING AND ALLOWING TREES TO GROW                                                                                                                                                                                                                                                                         This  really is a very good way of growing indigenous trees. In areas where trees have been chopped out because they have a good root base, if they are allowed to regrow they will become big trees for quicker than if they are grown from seed or cuttings.

WOODLAND AND WOODLOT MANAGEMENT

INTRODUCTION

We need to grow indigenous trees because they are an integral part of our rural communities and a basic part of our natural resources.  In providing a ground cover they help conserve the soil, preventing it from being wasted may and protecting it from drying out. They maintain or increase fertility. The roots bring up the nutrients that have leached out of the soil and deposit them in the leaves on the ground in the form of mulch.

They are a productive and renewable resource providing firewood, poles and fruit on a sustained yield basis.

Another advantage of woodlot management is that there is a low input cost and management is simple.

CHOOSING THE AREA FOR A WOODLOT

The area chosen for a woodlot need not be a formal one with regular sides particularly in rural areas. Hills and rocky places unsuitable for arable forming, contour ridges, the sides of arable lands where the woodlot can form windbreaks, stream and river banks or gulleys would all be good choices as they could become an ongoing and integral part of the community.

MANAGING THE WOODLOT

  1. a) Start by cutting out all the dead wood. Allow any cut trees to regrow from the stumps. When two to three meters tall reduce the number of coppice shoots to 2 or 3 per stump and later 1 or 2 so that they can become trees.
  2. b) If there are no seedlings or very young trees, seedlings should be grown and planted out or truncheons should be planted.
  3. c) Once the woodlot is established if there are any large trees which are no longer fruiting or seeding they can be cut out to make way for younger trees.
  4. d) When cutting for regrowth cut cleanly and close to the ground
  5. e) Protection from fire is essential. Fire breaks should be established round the edge of the woodlot and also through the woodlot so that if fire does start it can be controlled and not rage through the whole area.
  6. f) The woodlot should not just be a show piece. It should be used to provide firewood, poles and fruit. If one twentieth of the suitable trees were chopped down for firewood and poles every year the trees would have a twenty year cycle in which to grow and regrow.  Nobody wants very large trees for firewood and as the trees regrow the coppice shoots being reduced can also contribute to firewood.

DOCUMENTATION

Ignorance is most certainly NOT bliss.

There is so much that we do not know about growing indigenous trees that everyone should be given utmost encouragement to fully document all that they do, whether it be growing from seed, cutting, truncheons or regrowth.

Further this documentation should be collected and collated and eventually made available for the next generation so that they also do not have to start from stratch.

 

DICK HICKS  CHAIRMAN

 

 

 

Annona stenophylla. Photo: Bart Wursten. Source: Flora of ZimbabweBauhina thonningii. Photo: Jos Stevens. Flora of Zimbabwe