Tuesday 9 March 2021

Vanilla roscheri

Family:  Orchidaceae

The flower of Vanilla roscheri photo taken by Roddy JC Ward

The flower of Vanilla roscheri photo taken by Roddy JC Ward

A very attractive orchid that has a widespread range in eastern tropical Africa, from Kenya, Tanzania and Mozambique with one officially recorded record from South Africa. The specimens found in South Africa were found on the shores of Lake Sibaya by Mark Ward in 1983 where herbarium specimens were collected by him on the 05/02/1983 and again on 01/07/1983 which were submitted to the Herbarium at the Royal Botanic Gardens by his father Roddy Ward. I am very fortunate to have been given a live piece of the original plant collected.

Status in South Africa    

Near Threatened* D2 assessed on the 02.09.2005 by L. von Staden and J.E. Victor

Known from one location in South Africa. Potentially threatened by subsistence agriculture, expanding informal settlements and alien plant invasion. The national assessment is downgraded from VU to NT as other subpopulations just across the border in Mozambique could serve as sources of propagules to South African locations.


This species may be conspecific with Vanilla phalaenopsis Reichenbach f. from the Seychelles and with Vanilla madagascariensis Rolfe from Madagascar, if so, Vanilla phalaenopsis would be the correct name.


Vanilla roscheri is a leafless, terete liana-like climber with green succulent stems up to c. 1 cm in diameter and short roots at the nodes. Small brownish vestigial leaves up to 3 cm long are sometimes present at the nodes.

Here the vestigial leaves are clearly seen on Vanilla roscheri grown in my lounge from the original specimen discovered and collected by mark Ward at lake Sibaya

A very distinguishing feature of this species are two shallow channels on each side running the length of the vine between the internodes which are up to 15 cm long.

Here the one of the two shallow channels on each side the vine of Vanilla roscheri grown in my lounge from the original specimen discovered and collected by mark Ward

The inflorescence is many-flowered, up to 30 cm long, terminal or at the nodes. Flowers are large and showy, up to 15 cm in diameter, white, more or less flushed with pink, strongly and sweetly scented. Lip funnel-shaped, often salmon-pink or yellowish in the throat. Capsule up to 17.5 cm long

Photo of flower of Vanilla roscheri taken by Roddy JC Ward

Seed pods of Vanilla roscheri growing on Erythrina latissima photo taken by Roddy JC Ward

Seed pods of Vanilla roscheri growing on Erythrina latissima photo taken by Roddy JC Ward


Vanilla roscheri are found growing where it is hot and humid near to the coast in mangrove forest, evergreen scrub, coastal bush and forest, and in grassy fields with scattered trees at elevations in South Africa 1-100 m, elsewhere at elevations of 0 up to 1050 meters


Vanilla roscheri which is easy to grow likes to grow at warm to hot temperatures with high humidity with the lower part of the plant and the roots in shade, the top of the plant in partial shade to full sun for them to flower.

Seed pods of Vanilla roscheri growing on Erythrina latissima in full sun at Lake Sibaya Photo taken by Roddy JC Ward

They require a large pot filled with a very loose well drained open growing medium with lots of space for climbing. I grow mine in very coarse sieved well drained leaf mould containing many sticks and partially decomposed leaves to which can be added some crushed egg or snail shells. It is essential to add good drainage and airholes on the sides at the base of the pot or to place the pot on feet. The plants must be allowed to dry out somewhat before watering. Reduce the watering in the cooler months. They need good air movement and respond well to misting. They respond well to a regular addition of a very weak solution of liquid fertiliser. Flush out the pot well with clean water from time to time to avoid salt build up.

I feed my orchid plants with soluble inorganic fertiliser used in hydroponics for flower and fruit growth to which I add both humic and fulvic acid which gives excellent results. I occasionally water my plants with plant growth stimulants derived from sea weed.

The Royal Botanic Gardens at Kew

Herbarium Catalogue








Current Name:  

Vanilla roscheri Rchb. f.




Ward, C.J.; Ward, M.C.     

Plant Parts:        

Flowers/inflorescence; Fruit

Collector no:     




Collection Date:





South Africa


Light shade; sand termite mound. Dry woodland-forest, mainly just within margin. Frequency; Locally common.


KwaZulu-Natal Ingwavuma Sibaya lake south west

Plant Description:

Shallowly rooted in litter on sand or pseudo-epiphytic.

Lat and Long:

27 21 S , 32 36 E



General Comments:

Sheet 1. Duplicate Ex Herbarium: University of Durban-Westville, Natal, South Africa.







Article written by Michael Hickman from data collected from the websites listed below and from own experience growing this orchid


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Wednesday 18 November 2020

Evaluation of the Green roof trials conducted in Durban

A brief evaluation of the Green roof trials conducted in Durban over a period of ten years

Early in 2009 I became involved in the eThekwini Municipality Green Roof Pilot Project at which time I started the trial of a number of species of local plants at Mount Moreland north of Durban.

Delosperma lineare 

As from 1987, prior to becoming involved in the eThekwini Municipality Green Roof Pilot Project I had considerable exposure to green roof construction in Germany. Therefore, it was natural to copy as closely as possible the methods employed in green roof construction in Germany. Using drainage and engineered growing medium consisting of materials such as light weight expanded clay granules, perlite and vermiculite. In addition, we incorporated very little organic material as done in Germany with the percentage not exceeding 5%.

Ledebouria apertifolia

For many reasons it was decided to limit our research to exclusively local indigenous plants that occur naturally within 50 of the test site. In regards to my own testing I have added a few plants collected in the very hot and dry Ndumo area.

This evaluation has been done after most of my test plants had been grown for ten years with virtually no attention, being left almost completely on their own with no watering, no fertilising, no addition of soils to the trays or mulching with compost.

Gladiolus cruentus

Ten years later the evaluation of the projects has proven that  many of the practices carried out in Europe to not be true for our circumstances.

Firstly, drainage appears to not be essential because the drainage very soon becomes invaded by plant roots which decrease or completely prevents its operation. The reality is that during periods of heavy rain the majority of the water leaves the roof via surface drainage.

Specially engineered soils appear to not be essential other than they are a little lighter a factor that can very easily be mitigated during the design stage of the roof to allow it to carry a little more weight.

As observed in nature many of the plants that we trialled grow in humus rich soils on rocky slabs in nature. In literature found on the internet it is generally recommended not to add more than 5 percent organic matter to the growing medium mix. Experiments have proven that most of the plants that we did trials on grow better with considerably more compost. Recently since the end of the ten-year testing period I have found great benefit in heavily mulching the plants with fresh sheep manure just before the onset of the first rain in the spring time.

Clearly a great range of South African plants are extremely suitable for use on green roofs growing in shallow relatively nutrient poor soils

Many indigenous orchids are ideal candidates for growing on nutrient poor green roofs, especially orchids from the genus Eulophia, in particular the very showy Eulophia speciosa.

Eulophia speciosa

All of the local indigenous bulbous plants trialled have been an overwhelming success, one of the main reasons for this appears to be that during the period of maximum growth there is sufficient moisture for good growth from the rain with a dry period during the winter when they are naturally dormant.

A number of new plants have established themselves from seed that was blown in or brought in by birds. Of particular note are Bulbine natalensis, Cyanotis speciosa, Delosperma lineare, Drimiopsis maculata, the orchid Eulophia speciosa and a Plectranthus sp collected at Ndumo.

Below are lists of plants that I have trialled at my home in purpose manufactured planting trays most of which have been in trialled for ten years the minimum period that plants have been grown is 4 years.

Plants trialled that have done well

Adenium multiflorum

Aeollanthus parvifolius

Agapanthus campanulatus

Agapanthus praecox

Albuca fastigiata

Albuca setosa

Aloe arborescens

Aloe greenii

Aloe tenuior

Anthericum saundersiae

Ceropegia nilotica

Ceropegia stapeliiformis

Crassula expansa

Crassula lanceolata

Crassula multicava

Crassula obovata

Crassula ovata

Crassula pellucida

Crassula perfoliata

Crassula sarmentosa

Cyanotis speciosa

Cyrtanthus sanguineous

Delosperma lineare

Delosperma tradescantioides

Dipcadi viride

Drimia delagoensis

Drimia elata

Drimia flagillaris

Drimiopsis maculata

Drimiopsis maxima

Eulophia speciosa

Eulophia leitchii

Eulophia citellifera

Eulophia clavicornis

Eulophia parviflora

Eulophia unidentified Ndumo

Cheilanthus viridis

Gasteria croucheri

Gladiolus cruentus

Huernia histrix

Huernia zebrina

Hypoxis costata

Kleinia fulgens

Ledebouria apertifolia

Ledebouria revoluta

Murdannia simplex

Orbea longidens

Ornithogalum sp. Dwarf bought

Ornithogalum sp. Minute kloof

Pelargonium alchemilloides

Plectranthus neochilis

Plectranthus creeping sp. Ndumo

Scadoxus multiflorus

Scilla natalensis

Selaginella dregei

Vera-duthiea zebrina

Zingela pooleyorum     



Plants that have self-established

Scadoxus puniceus

Aloe maculata

Aloe ferrox

Euphorbia tirucalli

Plectranthus madagascariensis

Tetradenia riparia

Kalanchoe rotundifolia


Plants freely spreading from seed

Agapanthus praecox

Bulbine natalensis

Crassula expansa

Cyanotis speciosa

Delosperma lineare

Drimiopsis maculata

Eulophia citellifera


Eulophia speciosa

Murdannia simplex

Orbea longidens

Ornithogalum sp. Dwarf bought

Pelargonium alchemilloides

Plectranthus creeping sp Ndumo

Plectranthus neochilis



Bidens Pilosa established from windblown seed although they are aesthetically unwanted, they complete their life cycles or die from drought before they produce seed. Weeds have not been a threat to the growth or the health of the plants.

Under normal conditions weeds would need to be controlled mainly for aesthetic reasons as well as to keep the plantings purely indigenous.

Establishment of grasses

In addition to unwanted annual agricultural weeds the grass Melinis repens has established in some of the trays during the rainy growing season dying off during the dry winter leaving seed to resprout with a onset of spring rains. Melinis is probably a good and certainly an attractive addition on most extensive green roof plantings.

Cyrtanthus sanguineous

Conclusion and recommendations

The vast majority of the plants tested did extremely well.

Soil similar to the soils that the plants are naturally found growing in produced the best results however all plants grew satisfactory in a general fairly open well drained growing medium.

Occasional watering and the removal of unwanted weeds would be of great benefit.

An annual mulching with either a well-rotted and leaf mould of bark compost or animal compost such as sheep dung appears to be of great benefit.

I would not recommend the addition of inorganic fertilisers because they would promote weak rapid growth of the plants

Michael Hickman


Monday 5 October 2020

Dermatobotrys saundersii Tree jockey


Dermatobotrys saundersii Bolus.

Family: Scrophulariaceae

Common names: tree jockey


The genus Dermatobotrys is a member of the snap dragon family (Scrophulariaceae) which is related to the Tree Fuchsia, Halleria lucida. Dermatobotrys has only one species. Seeds sent to Kew in the 1890s germinated well and plants have been grown in cultivation ever since.


Dermatobotrys saundersii is an epiphytic shrublet that can reach one metre in height , which grows in the forks of a variety of trees, on the Pondo Palm or Coconut – Jubaeopsis caffra and occasionally on the forest floor.

Dermatobotrys saundersii. The leaves are soft and fleshy with shallow toothed margins and reddish veins. Under natural conditions the plant is deciduous, losing its leaves in late autumn. The tubular deep red flowers appear from mid-winter to mid-summer (June to December), followed by smooth oval brownish fruit filled with numerous small seeds in a sweetish pulp.

It's an odd member of the Snapdragon family that makes a caudex-like base and terrific flowers.  Even without blooms it's a first-rate house plant, with its woody stems and attractive leaves that have an interesting scent when rubbed.

Dermatobotrys saundersii develops thick, woody rhizomes that resemble a caudex.  From the base emerges a wavy mass of upright, woody stems, each about up to one meter long.  The leaves have a rubbery texture, with new growth that is tinged red or purplish.  When rubbed, they have a scent that is hard to describe, but it is sort of like lemon furniture polish!  It is not a bad scent, just an unexpected one for a plant.


In its natural habitat Dermatobotrys saundersii flowers in late winter when the days start to lengthen which brings this plant out of its dormancy to flower before the leaves are fully grown.



The fruits are relatively large, spinning top-shaped about 25mm long by about 20mm in diameter at their widest. The fruits have a bitter pungent smell and taste.

The fruits which ripen a few months after flowering are readily eaten by monkeys, hornbills and other birds in spring and early summer ensuring that the many hundred fine seeds per fruit, are distributed to germinate in leaf litter lined tree forks at the height of the rainy season. Like many of the family Scrophulariaceae the seed capsules and even the leaves when rubbed have a pungent smell. The fruits are eaten by forest birds which seem not to mind this acrid taste.

Conservation Status

Although it is regarded as not threatened, and assessed as Least Concern (LC) on the Red List of South African plants http://redlist.sanbi.org/species.php?species=1040-1 , this is a rare species with a high habitat specificity.

Distribution and habitat

This rare epiphytic plant is found in coastal scarp forests in South Africa on the Transkei coast on the northern banks of the Mtentu and Msikaba rivers close to the ocean. It also found growing further north in southern Zululand to in the canopy of our coastal forests at Ngoye, Nkandla, Qudeni, Ngome and Gwalaweni.

It is also found in Madagascar.


It is likely that this plant with its red tubular flowers is pollinated by sunbirds. The fruit has a most unusual scent, which may attract fruit eating birds and small arboreal mammals, which eat the fruit and distribute the seed.

Growing Dermatobotrys saundersii

These attractive plants are easily grown and make very good container plant subjects in particular when grown in hanging baskets. For best results treat Dermatobotrys saundersii as any other epiphyte, it is however important not to over water. Dermatobotrys saundersii grows best in a loose well drained growing medium with plenty of organic material such as leaf litter, compost or chopped coco nut fibre as sold for growing orchids. If grown outdoors or in a green house in areas prone to eel worm (nematodes) keep the plants off of the ground preferably in hanging baskets to prevent these pests from attacking the roots causing the plants to grow very poorly or in extreme cases killing the plants.

Although Dermatobotrys saundersii will grow in rather heavy shade it will not flower well, it flowers best in medium to partial shade and will tolerate full sun.

Dermatobotrys saundersii will grow indoors in a bright well-lit room or under lights where it will tend to flower at any time of the year.

When grown indoors Dermatobotrys saundersii prefers filtered sunlight or morning sun.  Protect it from strong afternoon sun.


I feed a weak solution of liquid fertiliser alternating between organic and non-organic fertilisers. Every once and a while the plants need to be drenched with pure water to prevent the build up of salts in the growing medium.

Pests and diseases

In the close on 50 years that I have grown Dermatobotrys saundersii I have found them relatively pest free other than being extremely prone to nematode attack if they are placed on the ground.


For best flowering results dry the plants off almost completely for two to three months in winter to let them rest as in their natural habitat. Your rewarded will be a mass of flowers just before the new leaves appear.


For propagating small numbers of plants Dermatobotrys saundersii grows easiest from cuttings preferably taken in summer which grow extremely easy placed directly into growing medium, sharp sand of a mix of sharp sand and peat.

For growing a large number of plants one would need to grow them from seed, I have had best results growing them on peat or coconut peat.

The delicate quick growing seedlings are very prone to damping off so they should be treated with a suitable fungicide at the time of planting the seed then periodically thereafter as per the instructions on the label. I have always successfully used Benlate active ingredient benomyl and Previcur active ingredient Propamocarb as a mixture to control damping off. The seedlings can be prepicked out into individual small containers from a height of 25 mm. Do not over pot. Repot into the next sized container only when they have outgrown the one that they are in.

The seedlings should flower in their second year.

I can supply both plants and seed

 Michael Hickman on 05.10.2020 


Monday 17 August 2020

African spotted orchid Oeceoclades maculata

 African spotted orchid Oeceoclades maculata

Family:                 Orchidaceae

Subfamily:            Epidendroideae

Tribe:                    Cymbidieae

Subtribe:              Eulophiinae

Synonyms            Oeceoclades mackenii


Distribution in South Africa:        KwaZulu-Natal

Widespread across the tropics of Africa and South and Central America, and rare in southern Africa.

A globally very widespread species, however in South Africa it is very rare, known from only a few records, but not suspected to be threatened. It may also be overlooked as plants are well camouflaged among shaded forest leaf litter.

The African spotted orchid Oeceoclades maculata, also known as the monk orchid, is a terrestrial orchid species that is native to tropical Africa, the sub-tropical east coastal region of South Africa and Madagascar. Oeceoclades maculata is considered to be one of the most successful invasive orchids which has naturalized in South and Central America, the Caribbean, and Florida in North America. It was first described by the English botanist John Lindley as Angraecum maculatum in 1821 based on a specimen collected from South America. Lindley later revised his original placement and moved the species to the genus Oeceoclades in 1833.



Oeceoclades maculata grows in leaf litter amongst rocks in the shade of riverine forest and woodland. It produces a very short rhizomatous stem that is covered with secondary stems that are expanded to form below ground, rounded pseudobulbs up to 6 cm in length.  From the top of the pseudobulb flattened a single linear leaf emerge that is up to 40 cm in length.


In their natural habitat they experience summer day temperatures of 27 -32 degrees C, and night time temperatures which average around 21 degrees C, with a winter minimum night time temperatures as low as 10 degrees C and daytime temperatures around 25 degrees C.


75-80% in summer dropping as low as 50% in winter.


Oeceoclades maculata which are easy to grow require shady conditions and filtered or diffused light. Good air movement should be provided at all times.


Growing media:

A mix of equal parts well decomposed leaf-mould, small crushed stone, decayed granite or river pebbles and medium sized composted pine bark compost works well. Oeceoclades maculata should be grown in shallow well-drained containers large enough for about 2 – 3 years growth. Repotting is best done in early spring as new growth resumes and should be avoided before the winter rest.


Oeceoclades maculata should be watered heavily while actively growing, but drainage must be excellent, and conditions around the roots should never be stale or soggy. Watering needs to be reduced for 2-3 months in winter


I use a balanced water-soluble hydroponics fertiliser to which I add equal amounts of fulvic acid and humic acid at a quarter to half a gram each per litre of water, applied weekly as a drench keeping the leaves dry when the plants are actively growing.

They should be allowed to become almost dry between waterings, but they should not dry out completely. Fertilizer should be reduced when water is reduced.

 Michael Hickman on 17.08.2020 

Sunday 3 September 2017

The Dangers of using Picloram in Conservation Areas

In 2013 I first began noticing what was very clearly herbicide damage and death being caused in particular to two species of tree being Grewia occidentalis and Trema orientalis. I took photos of the affected trees but could not establish the source of or the herbicide that had caused the damage.

Trema orientalis that has been damaged by a very small dose of the herbicide picloram and is about to die. This tree has died since the photo was taken

More and more I began noticing trees that had been affected or had been killed by what was very clearly as the result of herbicide poisoning but again I could not establish what herbicide had caused the death of the trees and when the spraying had occurred, in some areas the last spraying had occurred a few years previously.

About a year after first observing the herbicide damage to trees and other plants I accidentally discovered the culprit herbicide.

I had removed a narrow band of bark down to the cambium on three trees on my property and carefully applied a very narrow band of Kaput Gel containing Triclopyr and Picloram in a band of about 50 mm on the bottom half of the area where the bark had been removed. Within a few days I noticed that two trees growing within a meters of one of the trees started to show signs of herbicide poisoning and within two weeks one of the small trees Hippobromus pauciflorus was completely dead, the second small tree affected was Obetia tenax which very nearly died but eventually after more than two years recovered. For up to three meters along the line of the main roots all dicotyledonous ground cover plants were affected. A wild grape Rhoicissus tomentosa growing about six meters from one of the other trees was also very badly affected clearly from herbicide leached from the tree that had been treated with Kaput gel, eventually over ninety percent of the very large vine died what is left at the time of writing being August 2017 has not completely recovered.

Obetia tenax two years after having been poisoned by picloram which leached from the roots of a tree that was ring barked and was treated with a herbicide gel some distance away

Once that I had noticed how very small doses of picloram had affected other plants growing nearby I investigated what herbicides had been sprayed in the areas where so much herbicide damage had occurred and discovered Plenum containing Picloram has been sprayed to control weeds in adjoining grassland. In most areas where Plenum containing Picloram had been sprayed 100% of Trema orientalis trees had died.

Trema orientalis that has been killed by a very small amount of the herbicide picloram,note that the two trees growing beneath it have not been affected

Since then I have kept a very close eye on where ever I have seen contractors spraying or applying herbicides. Time and again I have found that Herbicides containing Picloram have caused excessive amounts of damage and death to a number of species.

I have observed that the following trees as extremely sensitive to very low doses of picloram

Barringtonia racemosa
Brachyleana discolor
Celtis africanus
Dombeya cymosum
Ficus lutea
Grewia occidentalis
Hippobromus pauciflorus commonly known as false horsewood
Obetia tenax
Scadoxus puniceus
Trema orientalis
Wild grape Rhoicissus tomentosa

Croton sylvaticus dying after picloram  that had been sprayed a year or two before  was washed down to the root zone following heavy rains 

 Research on the internet confirmed what I had recorded but also brought to light some alarming facts as to the danger of using Picloram in sensitive natural areas or near to them.

As a result of my own observations as well as what information I have obtained from the internet and a number of experts that  I have discussed the danger of applying Picloram with I will certainly never spray with any Herbicide containing Picloram in any natural area neither would I recommend any one else to do so.

I would go as far as to say do not under any circumstances ever spray with any herbicide containing Picloram in environmentally sensitive areas for instance in conservation areas or any other area when no damage to indigenous vegetation may occur. Also do not use herbicide gels containing Picloram and if there is absolutely no alternative then do so with extreme caution and only on plants that cannot be controlled with other herbicides because as reported above picloram leaches from the roots from the roots of plants that have been treated with it killing or damaging desirable plants growing nearby.

Damage has been caused to a Barringtonia racemosa a protected tree in South Africa at the uMdloti river lagoon by an NGO doing alien plant removal
Barringtonia racemosa a protected tree has been killed by the uninformed use of picloram at the uMdloti river lagoon by an NGO doing alien plant eradication

There is no need at all to use Picloram in natural areas because there are herbicides that are just as effective and are far safer to use so please do not use this nasty herbicide in these areas.

The following information in regards to picloram has been published on the internet.

Picloram is a systemic herbicide that belongs to the pyridine family of compounds, used for general woody plant control. It also controls a wide range of broad- leaved weeds excepting mustards (crucifers). Most grasses are resistant to picloram so it is used in grassland management programs.

Picloram can be sprayed onto foliage, injected into plants, applied to cut surfaces, or placed at the base of the plant where it will leach to the roots. Once absorbed by the foliage, stem, or roots, picloram is transported throughout the plant.

Picloram kills susceptible plants by mimicking the plant growth hormone auxin (indole acetic acid), and when administered at effective doses, causes uncontrolled and disorganized plant growth that leads to plant death.

Picloram is the most persistent member of its family of herbicides which does not bind strongly with soil particles and is not degraded rapidly in the environment, allowing it to be highly mobile and persistent. The half-life of picloram in soils can range from one month to several years.

As a result Picloram can move off-site through surface or subsurface runoff and has been found in the groundwater. Picloram may also “leak” out of the roots of treated plants, and be taken up by nearby, desirable species.

Concentrations in runoff reported by researchers are often adequate to prevent the growth of non-target terrestrial and aquatic plants, and therefore, picloram should not be applied near water.

Picloram is a dicot-selective, persistent herbicide used to control a variety of annual and perennial broadleaved herbs and woody species. It can persist in an active form in the soil from several months to years, and can also be released from the roots of treated plants into the soil, where other non-target species may take it up and be injured or killed (Hickman et al. 1989). The cut-stump treatment is typically used to control woody species. Picloram is metabolized slowly by microbes and can be degraded through photolysis when directly exposed to sunlight. The half-life of picloram in soils can vary from one month to three years depending on soil and climate conditions. Other methods of chemical degradation do not occur readily. Picloram does not bind strongly with soils and can be highly mobile, moving to soil depths of two meters and laterally to one km.

Picloram is not readily degraded in soils and can be persistent and mobile. Estimates of the persistence of potentially toxic concentrations vary from a few months to three years, depending on soil and environmental conditions (Scrifres et al. 1972; Fryer et al. 1979; Johnsen 1980; Norris et al. 1982; Neary et al. 1985; Smith et al. 1988; Bovey & Richardson 1991; Close et al.1998). In soils where picloram persists for long periods of time, it has high potential to move vertically and horizontally, which can lead to contamination of water sources and non-target (terrestrial and aquatic) sites. Smith et al. (1988) reported that one and two years after treating a site with 3.38 kg/ha of picloram, residues were found in the soils and groundwater of an untreated site one km away.

Because picloram is water-soluble and does not bind strongly to soil, it is capable of moving into local waterways through surface and subsurface runoff (Michael et al. 1989). The extent to which picloram enters a waterway depends largely on the type of soil, rates of application, rainfall received post-application, and distance from point of application to nearest water body or groundwater (Trichell et al. 1968; Baur et al. 1972; Mayeux et al. 1984). In general, the larger the buffer between treated sites and surface water bodies or groundwater, the smaller the potential for water contamination

In non-susceptible species such as grasses, picloram is metabolized rapidly, while in susceptible species, picloram can remain intact for extended periods (WSSA 1994). When applied to soil, picloram is readily absorbed by plant roots. When applied to foliage, the majority of picloram (70-90%) remains in the leaves and only a small percentage is conducted to stems and roots (Meikle et al. 1966; Cessna et al. 1989; Hickman et al. 1990). Unabsorbed picloram remaining on leaf surfaces may photo degrade in sunlight or be washed off with rainfall or irrigation. Picloram absorbed by plants can be released into the soil by passive transport through the roots and then taken up by roots of other nearby plants (Hickman et al. 1990). Therefore, even selective application of picloram to specific target plants could potentially harm nearby desirable


Chemical name: 4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid
Chemical class/use:         chlorobenzoic acid herbicide

Picloram is sold in South Africa under the following brand names

Picloram is found in various herbicide mixes in South Africa under the following names
Plenum - Active Ingredients: Picloram (80g/l), Fluroxypyr (80g/l)
GLADIATOR 160 ME – Active ingredients: Fluroxypyr 80 g/l, Picloram 80 g/l
There could be others

Weed Control Methods Handbook, The Nature Conservancy, Tu et al. 

Extension Toxicology Network, A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Michigan State University, Oregon State University, and University of California at Davis.

Most kindly written for me for publication by Ecoman Michael Hickman on 20.08.2017 

Vanilla roscheri

Vanilla roscheri Family:   Orchidaceae The flower of Vanilla roscheri photo taken by Roddy JC Ward A very attractive orchid that has...