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.

Planting columnar cacti and euphorbias

Today something about (re-)planting the big (columnar) cacti and euphorbias.

It’s simple: Plant it in such a manor that it can resist a strong wind without ‘bending over’ ending on the ground. And that you prevent the plant from neck-rot.

Make a hole deep and wide enough; better a bit too deep and too wide. Make a soil mix as described in the contribution about cuttings.

Loosen the soil on the bottom of the hole and mix it with the self-prepared soil.

Top this with a layer of approx. 5 cm self-prepared soil.

Place carefully the plant in the hole and spread the roots. Top the roots with a layer of 10-15 cm of self-prepared soil.

Put large rocks in the hole around the plant with a distance of 5 to 10 cm from the stem. And that their tips stick a little bit above ground-level.

Put the rest of the self-prepared soil in such a way that you compact the soil between plant and rocks. And that you shape a small heep around the stem ending at the outer-side of the rocks. This will let the surplus of rain water drain away from the plant keeping the neck as dry as possible.

This method has the ‘disadvantage’ that you have to plant deeper as they were at the nursery or in the pots. This extra depth means a year (or more) of growth before the plant, above ground-level, is as high again as you bought it.

The big advantage of this general method is, provided you did it right, that the columnar cactus or euphorbia will stand as a rock in the wind.

We learned this method in a natural way in one of our gardens. When this first cactus garden in South Africa was planted almost a 100 years ago Marthinus Malherbe planted all the collumnar cacti and euphorbias that way. During the restoration of this garden we had to take (after 24 years of neglect) almost all succulents out and remove the contaminated soil. Removing the big ones was quite a job for their root-system was covered with huge rocks. But not one columnar cactus or euphorbia  ‘tipped’ in 90 years despite the heavy winds every now and than.

Rot

Whatever you do to avoid it; sooner or later there is a plant with rot. We recently experienced this with a quiver tree which prosphered in one of the gardens for more than 6 years. And suddenly, at the brink of the South African Autumn, the tree let us know that there was such a ‘soft feeling’ at its neck. Taking the soil away we discovered that part of the neck just started to rot. We took it out (almost 150 kilogram) and laid it to rest in the barn. The past week we’ve taken the rot parts away and let dry for the next few months until Spring before we replant it. Luckely for both, us and the tree, some of the roots were not attached. In October we will replant the almost 3 metre high tree on a somewhat higher spot and we’ll cover the neck and the top part of the roots with coarse sand for better drainage.

Rot can never be avoided in full but some measurements can avoid at least 90 percent of the misery.

It starts with buying your succulents.

And plant them in the right soil; more or less the mix as described in one of the contributions last month.

The top layer of the soil should be 30 to 50 cm deep and the subsoil should  be able to drain the surplus of water sufficiently even after a heavy rainfall.

Keep the soil around the plants free of weeds.

Plant vunerable succulents on a small sandy heep (5-10 cm high).

After (heavy) rainfall aerate the soil around the plant (loosening the top few centimetres).

But still than, as in our case with a very valuable quiver tree, rot can strike suddenly.

Neck-rot is caused by phytophthora. This is a fungus which also occurs in potatoes and caused the Irish famines in the 19th century and with that the Irish influx in the America’s.

There is not much what you can do in a natural way other than taking the affected plant out and cut the rot part out. If you discover the disease in a late stage it can be too late for the whole plant. The only thing left is to cut the plant off above the neck and let the stem dry first and than root again as a cutting.

ALWAYS remove the soil around the affected plant (it might be contaminated) and do not add the attached parts (or whole plants) to the compost heep for it will spread the disease to all the places where you spread the compost.

Connie Krochmal, the cactus and succulent editor of Bella Online, recently wrote an informative article about all kinds of (rot-related) diseases in cacti and other succulents such as fusarium, botrytus and (powdery) mildew.  

At last but not at least: communicate with your plants. They will tell you about their needs, their shortcomings, their symptoms of ‘illness’. Talk with them with your eyes, your fingers, you nose and also with your mouth. It helps. Really.

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.

About Aloes

The genus name Aloe is derived from the Arabic, alloch and translated as allal in Greek and Hebrew, literally meaning bitter or bitter sap which is descriptive of Aloe sap. The genus Aloe belong to the family Asphodelaceae to which also other succulent genera such as Haworthia and Gasteria. A widely spread misunderstanding is that also the Agave and related American genera belong to the same famly. These belong to the family of the Agavaceae. Some Aloe species (f.e. A. Ferox, A. Barbados and A. Socotrine) are valued for their medical properties. There is however a large number of medical claims which are not scientifically proven up to date or are proven to be false. The globally best known Aloe is the Aloe barbadensis (better known under the previous botanical name Aloe vera). The Aloe barbadensis is commercially cultivated in the USA, Australia and India. In Maharashtra, Madhya Pradesh, and Gujarat, India, Aloe vera is raised as an organic. The crop is ready for harvest after 18 months from sowing. The average yield for organically grown aloe is approximately 12 t/ha. 

 Soil

A slightly alkaline (up to pH 8.5) sandy loam soil is the  most ideal for most Aloes but some prefer slight acidic soil (pH 5.5-6.5) such as A. mitriformis (A. perfoliata) and A. plicatilis. It is normally propagated through root suckers or by cuttings of the new growth. Because Aloe plants consist of 95% water, they are extremely frost tender. If they are grown outdoors in warm climates, they should be planted in full sun, or light shade. The soil should be moderately fertile, and fast draining. Established plants will survive a drought quite well, but for the benefit of the plant, water should be provided. 

Pests:

All known garden pests can be kept to a minimum by simply ensuring optimal growing conditions and a good selection of plants that attract wildlife to your garden. In principle a garden is always un-natural. One of the challenges of organic gardening is to make use of nature in order to strive towards an ecological balance. For our and your dissapointment: even nature is never in balance. There are many ‘surprises’ every year but without ‘ecological measurements’ these can go a bit out of control. A daily ‘inspection’ walk in the garden -preferable early morning or late afternoon- helps the gardener to foresee ‘threatening’ pests and diseases and making the right decisions towards preventive measurements.

Most common pests/diseases in aloes are aphids, scale insects and cancer.  

For scale insects the best results are obtained by physically removing scale using a cloth.

Occasional aphids on flower clusters and scale insects on leaves. These are relatively easy to control with water (high pressure) of, even better, preventive with a tea of garlic. Aphids are ‘farmed’ by ants. The ants regard aphids as their ‘milk cows’. Keeping ants away, two rings (10 cm or 4 inches space between them) of chalk powder on soil around aloes, minimalise the number of ants and aphids. 

Cancer: Caused by aloe-cancer mite.  This mite lives inside the plant and is the carrier of the virus and cause the cells to multiply and form ugly weird growths.  Cut out the affected part of the plant and let it dry.  General info about pest control and pest and disease prevention can be read elsewhere in this blog  

Propagating

Propagating is best done via cuttings. Sowing is also possible but bear in mind that Aloes hybridize easily. 

Southern Africa is home to a few hundred Aloe species. Two of our favorites are the Aloe perfoliata and the Aloe polyphylla. 

Aloe perfoliata

Growing A. perfoliata is very easy. The best results are achieved by simply making stem cuttings. Allow cuttings to dry for a few days and insert into river sand and keep moist. The roots appear after about two weeks. Seeds must be sown as fresh as possible. When kept too long they are parasitized by small crawling insects. The best time for sowing would be in the winter, June to July. Use coarse river sand and cover seeds lightly, then keep moist. It is advisable to treat seeds with a tea of khaki-bush, as seedlings are prone to damping off, a fungus that eventually kills the young plants. Simply add tea to the soil. After germination, when plants are about 20 to 30 mm, plant over using a sandy-loam medium. If you have a garden with clay soil, use some bone meal to break up and nourish the soil. Mature plants in the garden may from time to time be subjected to attack from scale insects and aphids.

Aloe polyphylla originates from high, relatively cold, altitudes in Lesotho. It is a very difficult plant to cultivate in the open in the Western Cape. It’s main requirement is well-drained soil. It performs best when planted on a slope (or planted up at a slight angle so water does not collect in the spiral), where it can enjoy sun, or part (afternoon-) shade in the hottest areas. It also does well in pots. Water requirements depend on soil and weather. They are generally suited to low water, but prosper with some summer water. 

Information about South African Aloe species can be obtained via one of the websites of the National Biodiversity Institute. This site contains a wealth of info of many indigenous plants including succulents.