Thrip, aphid, worm and beetle control

Insect repellent teas can be made from any strong aromatic weed steeped in water for 48 hours.

A good result in the control of beetles, thrips, worms and aphids can be achieved with this recipe:

2 cloves of garlic shredded and placed in enough water to cover. After 24 hours add a teaspoon of cayenne pepper, mix it and wait another 24 hours.

Add 500 ml water for a concentrate. You need only 10 ml of the concentrate for 1 liter repellant. Per liter repellant add 1 drop of bio-diswash liquid. Apply every 3 to 4 days until the populations of the different insects are manageble.

It works.

(The original recipe is from New Plant Nursery in George, South Africa)

Organic pest- and disease control training

Just a link to the website of one of the South African experts of organic pest- and disease control.

Johan Gerber’s School of Environmentally-Responsible Garden Care has initiated a Integrated Pest Management-endorsed training which is held at a reseach farm in Roodeplaat (Pretoria). See the webwite for details. Interesting stuff for all who want to minimise/eliminate the use of chemicals in the garden.

Although we are not able to attend the training we can dearly recommend it to all. Johan, who visited South Africa’s own Primary Unusual Destination a few years ago, is really passionate about the Green Life.

His websites are:

http://www.gardencare.co.za/links.htm

http://www.gardencare.co.za/orgfarm.htm

http://www.gardenguardian.co.za
 

bone meal and sea weed

Towards the end of the South African winter it’s not a bad idea to provide the Spring growth of plants with an organic ‘headstart’.

In Wikipedia you can find a few articles about organic soil improvers.

Look under bone meal and sea weed. Both stimulate the root growth. Good healty roots are the foundation for a healthy growth of the plant.

What’s not mentioned in Wikipedia is the use of composted horse manure; also rich is phosporous like bone meal but not the risk of contamination with lead and so on as some bone meal products.

Sea weed is available in South African shops as SeaGro and in large quatities at agricultural suppliers as Kelpak. It’s a true South African product (Made in Simonstown). Just spray it on plants and soil at the end of August and once more in mid-October. Bone meal: a little hand full around every plant and slightly cultivate it in the soil. Only once a year around this time. And don’t believe what the manufacturor writes on the package (“every six weeks”). Plants can get killed due to an overload.

Composted horse manure: Spread  between the plants and with a bit of cultivating mix it with the top soil. Here we are glad with a horse keeping neighbour. Thoroughbreed horses with honest natural food without hormones and other ‘boasters’.

One golden rule: Too much is too much. Relativily small quantities are the best. Don’t make it too easy for plants (they get vunerable for diseases and pests). Life is hard; should also be for plants. That makes them strong.

Keep on talking with your plants.

About Euphorbias

The Euphorbiaceae family consists of around 300 genera and about 7500 species of which approximately 870 are succulents. About 50 genera and 487 species are native to Southern Africa including Madagascar. These figures excludes the numerous varieties and hybrids such as those of the E. milii and E. pulcherrima (pointsettia).

The International Euphorbia Society covers the whole spectrum of this plant family including the non-succulent ones.

General information about succulent Euphorbias can be found here. The most valuable Internet source (including photo’s and cultivation info) however can be sourced at this site.

Euphorbias are named after the Greek surgeon Euphorbus.

Most of the succulent species of the Euphorbia are easy to grow in most parts of South Africa provided that there is sufficient drainage and the humidity is low. High humidity causes mildew and, combined with high temperatures, mealy bugs. Good drainage prevents Euphorbias from root mealy bugs and root rot (caused by fusarium fungus). Plant Euphorbias preferable on a slope and in well drained soil. Large collumnar plants always surrounded by rocks. In general Euphorbias are less susceptible to diseases than other succulent families. In the past we already submitted something about pest and disease control the green way . See also this contribution and these ones.

Propagation can be done by sowing and by means of cuttings.

Some Euphorbia species hybridise easy and to prevent this as much as possible is hand-pollination with a brush. Always plant two of more plants of the same specie next to each other.

As for cuttings: cuttings of succulent Euphorbias can best be taken towards the end of the dormant season. We normally take them towards the end of the South African Summer (February-March) and always in the early morning but preferable in the late afternoon. Keep the cuttings under a running tab until the cutting stops ‘bleeding’ latex. This milky sap is poisonous (always wash your hand afterwards and or wear protective clothing). Let the cuttings dry in a dry shady area with good ventilation for at least 3 to 4 days before planting them.

Winter tip succulent gardens

Many South Africans assume that a waterwise garden means a “low maintenance garden”.

In our daily practice at Soekershof Walkabout we regulary have discussions with nursery customers about the importance of maintenance. Weeding and ‘communicating’ with plants is an ongoing process; especially in the Winter rainfall area as the Western Cape. Last weekend we had some showers and the weather forecasting shows us raising temperatures for the next days. For our gardeners the sign to aerate the soil around the succulents with a cultivator. This let the moisture evaporate faster and keeps the neck (neckrot) dry. Another good reason to do so is that with the next rainfall the surplus of water will drain away easier. While cultivating they always feel the neck just under the surface just to make sure that these are still fleshy and not soft. Cultivating and weeding go hand in hand. Partly cultivating is weed prevention because the soil dries out faster and weed seeds generally don’t germinate in dry soil.

Asclepiads

This group of highly succulent, more or less leafless plants belongs to the family Apocynaceae. Found exclusively in the Old World, they are widely distributed over the drier parts from the Southern-most tip of Africa to the southern shores of Europe and eastwards to Arabia, India and Myanmar. Of the roughly 330 known species, 182 occur in Southern Africa, and all but a handful of these are endemic to this region.

Asclepiadaceae is a plant family which differs from others by having a very complex sexual apparatus and a complicated pollination procedure. They are easyly recognisable by five-lobed flowers. The lobes are joined together at the base of flower (corolla).

There are about 2000 species of Asclepiadaceae split into some 300 genera, of which about half are succulent. The succulent ones are of interest, especially the group named stapeliads. Their flowers are miraculous. I have read somewhere:  “Orchids of the Succulent world”/   The flowers of stapeliads have one flaw only. Most of them don’t have a pleasant smell.

Asclepiads grow worldwide, from jungles of Indonesia to deserts and steppes of Africa while stapeliads grow only in the old world. There are some representatives in Europe, too, in Southern Italy and Spain. Most of them are from dry regions of South, East and North Africa, Arabian peninsula and some even from India, Sri Lanka, Myanmar (Burma) and Nepal.

Most Asclepiads enjoy warm conditions, and appreciate regular application of water  in hot Summer weather providing that the plants are in their growth phase. For some of the more difficult Asclepiads, heat is a requirement and watering should be more circumspect. At Soekershof Walkabout we always use rain water, and tend to water over the top of most plants – after all that is how it happens in habitat. However, many growers prefer to water plants from the bottom (simulating drier conditions where the roots seek underground moisture), and a careful approach to watering is essential for difficult or rare plants.  It is a good idea to allow the soil to dry out between waterings, and if the weather goes cold in the middle of the summer, then stop watering. Much of the reputation that Asclepiads have for rotting unexpectedly is probably related to watering plants too early in the year while still dormant, or when the weather is uncertain, or to attack by other pests such as root mealy bug, the damage from which allows disease into the tissues. Indoors Asclepiads seem to do best in very free-draining gritty compost  which helps the compost to dry out between watering. Peat-based composts, with lots of sharp sand and fine grit works well, but peat also encourages root-mealy bug.Always remove dead plant material (dead flowers, leaves, stems) from your growing space, as otherwise in damp weather it will become colonised by fungi and rapidly become a source of spores, which may in turn infect your asclepiads.

If a plant that was growing well suddenly goes into a decline, suspect root-mealy bug. This pest destroys the roots, preventing proper uptake of water, so the plant looks under-watered even though it is sitting on soggy compost. Probably the damage also helps fungi to enter the tissues, and the next stage is a rotten plant.
Ordinary mealy bugs are also a major problem with Asclepiads, and are difficult to eliminate from crevices between the stems. Mealy bugs can be spread through a collection by the wandering vegetative growth of tuber-forming Ceropegias. Scale insects are said to be a major pest of Asclepiads in some climates.
It is a good idea to take cuttings from suspect plants that are not thriving, clean off obvious infestation and start off some new plants in case the original can not be saved. 

 Here we replant most of the asclepiads (especially Stapelia-species) every one of two years on a new location. This also prevents rot caused by soil related fungi, etc.

 

Propagation

Many Asclepiads are readily grown from seed, and some people grow plants of the faster growing species to flowering size from seed each year, thus avoiding problems of overwintering. However, the seed of many species (e.g. Stapelia sp.) has a limited life expectancy, and should be sown fresh. Those species with fleshy stems are easily propagated from portions of the plant laid flat on a gritty potting mixture, when they will produce roots from the underside of the stems. Planting stem cuttings vertically seems generally less successful (an exception is the vine-like Ceropegia species e.g. C. radicans), and the portion of plant embedded in the compost is prone to rot rather than root. Tuber-forming Cereopegias can be propagated from small tubers formed at joints in the thin stems. Regular propagation of plants with a few cuttings seems to be the best insurance against loss of the main plant.

  Internet literature:

 Stapeliads 

Pollination 

Articles about stapeliads 

Grafting stapeliads

 Ceropegias:  

 

About Crassulaceae

The Crassulaceae or orpine family consists of 33 genera with a total of around 1400 species. These dicotyledons have the characteristic that they store water in their leaves. Most species are native to Southern Africa and the Northern Hemnisphere.

Another characteristic of this family is that the different species hybridise easily. Advised propagation is (leaf-)cuttings but for gardeners who like to experiment with cross pollination the crassulaceae are very rewarding.

All crassulaceae originate from areas where water is (sometimes) scarce.

In the Western Cape: no additional water in Winter but during long dry spells in Summer Crassulaceae will reward you with extra growth if you give them a good morning soak once every week.

Tip: cut flowerheads out of young plants. This will stimulate growth and spread.

Soil: In general Crassulaceae are not fuzzy about soil as long as it drains and the pH is somewhere between 6.5 and 8. They even grow in heavy clay but too much clay has the disadvantage that after heavy rainfall followed by high temperatures there is a risk of rot.

Pest and diseases: Most common are aphids which are a real pest for some Crassulaceae. Aphids can become a plaque during high temperatures after rainfall.

Crassulaceae originate from areas with a wide scope of temperature-zones (USDA 6-10/11) but most from (sub-)tropical climates.

In South Africa we experience regulary that overseas Crassulaceae like the ones blonging to the genera of Aeonium and Echeveria are sold as “indigenous” by nurseries. Maybe because some of the species of these genera are common in many South African gardens.

Some of the more common known, except the ones mentioned, genera of the Crassulaceae are:

Dudleya; Sempervivum; Sedum; Tylecodon; Cotyledon; Andromischus; Monanthes and Kalanchoe.

Three of our favorite Crassulaceae:

Kalanchoe marmorata: Originate from Ethiopia, Sudan, Kenia. This Kalanchoe has paddle-shaped blue-green leaves with purple markings. Attractive in any rockery of succulent garden. Large white pinwheel flowers in clumps. Easily to propagate with (leaf-)cuttings.

Crassula columnaris (“koesnaatjie“): This monocarpic dwarf (Western and Northern Cape) needs at least 5 years to mature and becomes 5 cm high. When mature it starts to flower. It can grow in full sun in well drained (slightly alkaline) soil. The plant will tell you when it needs water (shriveling leaves). The scent of the flower is divine. Propagation by seed or leaf-cuttings.

Kalanchoe orgyalis: This native from Madagascar is relatively rare in cultivation. This Kalanchoe has thick velvet-like leaves which makes it sensitive in climates with a high humidity. The leaves are silver toned mahogany coloured. The flowers are bright yellow. This specie becomes about 50 cm high but that can take a while. Kalanchoe orgyalis is very, very slow growing in comparison with the other species of this genus.