Articles: BULB CHAT November 2002 PDF Print E-mail
Thursday, 26 May 2011 23:26

BULB CHAT NOVEMBER 2002 No. 33

MORAEA BARNARDII

Once again an interesting Moraea story. At the exhibition that we had with the Clivia Club a member had a pot of Moraea barnardii on show. The plants were all about 10 - 15 cm tall. Johan Loubser tells us that this is about normal for this species when in cultivation. In the wild the plants could be taller but they tend to shrink in cultivation. He also told us about the time that he had collected this delightful Moraea and had taken it to Kirstenbosch to be identified. On the steps of the herbarium he met one of the botanists, Tom Barnard, who immediately

identified it as the Moraea that was named after him.

WATSONIAS

Many different Watsonia species have flowered during the last two months. Near Paarl there are many pink Watsonia marginata plants in flower at present and they should be flowering all through November. Watsonia marginata is the only Watsonia species with actinomorphic flowers. All the other Watsonias have zygomorphic flowers. The leaves of Watsonia marginata are distinctive. The grey leaves are unusually broad and have thickened margins.

The monograph on Watsonias by Peter Goldblatt is out of print and any members who could still lay their hands on new copies should do so. The price of this book is going to start escalating in the near future.

ANOTHER NEW BABIANA

We have heard that another new Babiana was found in the Klein Karoo near Oudtshoorn. It is apparently one of the actinomorphic species. Flowering time is September. We are waiting for more detail from the professionals.

WHAT TO SEE AND WHERE

November is a rather dull month for botanising so let's try to make the best of it. You could see Gladiolus undulatus all along the road on Bain's Kloof. There are also more than one species of Watsonia flowering on Bain's Kloof at this time of the year. The bright orange Watsonia stenosiphon is flowering strongly around Kleinmond. Near Betty's Bay you should still find Gladiolus carneus flowering on the undeveloped plots. It is the pink variety with strong markings on the lower tepals - the real "painted lady". Ixia paniculata can be seen in flower in damp areas around Durbanville. We have for some unknown reason found this species difficult to get to flower well in cultivation. Maybe we are not keeping them wet enough during the growing season. Near Cape Point the bright red Watsonia tabularis comes into flower towards the end of November. It is always worth your while to go to the Cape Point Nature Reserve during November and December, because you will surely see bulbous and cormous plants of interest there. Watsonia borbonica is also found at Cape Point at this time of the year. If you are very lucky you could also find Gladiolus vigilans at the C.P. Nature Reserve. This rare plant has a very localised distribution in some of the hills in the C.P. Nature Reserve. The flower resembles G carneus but the leaves have thickened margins and midrib.

Near Rawsonville, along the road to the jail at Worcester, you should find tall Ixias. The flowers are mauve and they have a dark green central spot. This plant has never been positively identified, but they have done well in a pot for the past 8 years. Near Goudini Spa Ixia metelerkampiae can be found at this time of the year. The flowers are pale pink to mauve with a maroon central star. If you are feeling lucky go and search for Ixia cochlearis on the slopes of the Jonkershoek and Banhoek Mountains near Stellenbosch. This pink Ixia was last seen there in 1944. Imagine if an IBSA member could find this plant again after 58 years!!

DO'S AND DON'T'S FOR BEGINNERS

Since many of our new members have come to us from clubs such as the Clivia Club where they were experienced mainly with rhizomes and tubers some general hints on bulb/corm cultivation seems only fair.

1. Distinguish your potting between bulbs and corms. The bigger bulbs have mostly persistent

roots - usually large fleshy ones not unlike orchids - and these should be kept moist but

not wet. Corms, on the other hand, must be allowed to be completely dry during dormancy.

2. Very roughly it could be said that corms begin to be active 3 months before flowering. A

minimal amount of water can be given at the start of the 3 months but in general watering

should not start seriously until the first shoot appears. Even then water should be applied

sparingly and continue in proportion to the amount of stem and/or leaf that develops.

3. In most cases ( and particularly in large ones ) bulbs are not specific to soil, but corms

generally are. Thus corms from Fynbos prefer acid sandy soil whereas those from

Renosterbos grow in neutral or fairly acid loam derived from dolerite or slates.

4. All pots must be well drained. If more water is needed, water more frequently rather than

reducing the drainage.

5. At the onset of dormancy do not normally try to delay it by continuing watering. Taper off

your watering as dormancy develops. The only exception to this is that first year seedlings

are usually too small to store sufficient moisture so very slight and infrequent watering

( mere moisturising ) can be an advantage during dormancy in the first year.

6. All bulbous and cormous plants grow in cool soil but flower in warm sun so arrange matters

so that the sun does not strike the sides of the pots, heating the subsoil. One way of

achieving this if you are using plastic pots is to glue shade cloth to the exerted rim of the

pot. Other methods will occur to you.

7. Stone chips for drainage must not be placed so as to block the drainage holes. The chip

base needs to be not less than 3cm. This dictates the depth of pot required. It must be

deep enough that the vertical roots are free above the stone chips.

8. Some growers layer the soil in the pot with different size of soil particle below, at, above the

corm and on the surface. Do not try that until you are experienced. Start with a single mix

throughout.

9. Our plants do not prefer strong nitrogen therefore do not use manure or a commercial

fertilizer with a high nitrogen content. When you are first learning you do better not to use

fertilizer at all because it can do more harm than good if wrongly applied. 10.There is no standard potting mix because the water-retaining property of loams vary. A mix

of 4 parts sand to 1 part loam is fairly safe, but if the loam is water-retaining increase the

sand element.

11 Beware of mulching. It keeps the soil surface cool but it often allows mildews etc to grow

and it protects insect predators.

12 If your leafage develops yellow you are over watering. If the plant grows lank and floppy, it

is a sign of not only over watering but also too much shade.

13 Sow seed fairly thickly. The seedlings distribute nutrients through roots that touch each

other and you will get better and stronger germination.

14 Do not start by trying to grow rare and difficult species. Start with fairly common ones and

do not initially try to grow too many species. Lachenalias are generally easy to grow and

make good learning species. Any experienced member will be able to suggest easy

species to start you off.

15 Translocated bulbs and corms ( particularly corms ) are liable to sulk, so do not ignore

seed. It will teach you more and give you more permanent good results.

16 As you progress learn to know your plants, their likes and dislikes. Make notes as you go

along.

17. A plant uses a lot of energy to make seed and in most of our plants there is far more seed

in a single pod than you are likely to want so do not allow many pods to form. Let the

energy rather go into making next year's plant. Two or three good pods are ample. Pick off

the other dead heads once you see sufficient pods forming, usually at the bottom of the

spike.

18. Having sown your seed thickly the time will come to prick out. This is usually in the second

year and the time to do it is when the seedling has gone dormant. NOT BEFORE THEN.

When you prick out make sure the pots into which you put the specimens you want to

keep are wide enough to allow the young plants to develop.

19. Bulbs are perennials : the new year's specimen grows from the previous year's bulb. The

new year's corm grows from the previous year's corm by absorbing from it all its nutrients

and the old corm shrivels and dies. In both cases it is advisable not to lift mature

specimens between seasons. The less you interfere the less chance there is of sulking

and trauma.

20. Do not get all up tight to start with over diseases etc. Learn to grow before you set up as a

plant doctor. If there are definite signs of ill health ( not just impatience ) you will need to

get advice but it is very seldom that when you start with reasonably common species you

will have trouble. Just make sure that what you sow looks healthy and free of insect

predators or fungus etc.

These are guidelines, they are not rules! If you want rules take note of the following :

Know your plant. Read up about what you are going to plant. This will enable you to know

when it is going to flower, does it need a dry dormant period, can it take full sun.

Bulbs and corms in pots demand good drainage, corms even more than bulbs.

Never pot your newly acquired plants into pots filled with the soil from the collection site. You

are going to compromise drainage. If you want to use some of the collected soil sterilize it

with boiling water and spread it out on the surface of the pot. The nutrients will leach into the

soil.

Experienced growers : please don't push beginners too far and too fast. A beginner will learn more from a Gladiolus alatus than from a Gladiolus caryophyllaceus. When he or she can grow G. alatus successfully then advance to more difficult species - G tristis and G carneus are also good starters for beginners, both from seed or growing corms.

EXPERIMENT K67

WANTED : Members who are interested in growing one pot of seed. The pot and the seed will be supplied. The seed is of a common species. This would be particularly suitable for new members who have not previously tried growing Irids from seed. Phone - 021 5586537

GLADIOLUS PARDALINUS

One of our overseas members is touring our country at present. He only grows scented plants. Our Chairman gave him directions to this extremely beautiful Gladiolus, somewhere in Mpumalanga. The known site had unfortunately been used for housing but our member found flowering specimens nearby when he looked for similar soil to what he saw at the original site.

Gladiolus pardalinus is a tall plant ( up to 55 cm high ) with pale yellow flowers. The flowers have striking dark red markings. Flowering time is from mid-October to November. Pardalinus means leopard-like, so named because of the flowers. This is a summer rainfall species well worth cultivating if you can get hold of seed. Unfortunately this plant was not illustrated in the Gladiolus book by Goldblatt and Manning. It was at first regarded as a minor variant of the more widespread Gladiolus woodii, but is in fact a taller and sturdier plant than G woodii. Gladiolus pardalinus has 3 or even 4 smooth leaves compared to G woodii which under normal circumstances also has 3 or 4 leaves but only one leaf when not flowering. Gladiolus woodii leaves are slightly hairy. Gladiolus pardalinus flowers have a faint acrid odour.

G pardalinus was discovered in 1957 by L.E. Codd but as previously mentioned the new discovery was lumped with Gladiolus woodii by Amelia Obermeyer when she completed G.J. Lewis's revision of Gladiolus in South Africa.

LACHENALIA CAMPANULATA

This is a rare Lachenalia found in the mountains of the interior of the Eastern Cape. Plants have become available from The Croft Nursery in Stutterheim. The flower colour ranges from pure white to red to even a dark purple. Lachenalia campanulata has a dense inflorescence. The flowers are spreading to horizontal. The stamens are exserted and a bright yellow. The plants have 2 slightly erect linear leaves. Flowering time is right now ( November ) in cultivation. Members who are interested in plants of the Eastern Cape should get into contact with The Croft Nursery for their catalogue - 043 6832796.

FLOWER COLOUR

Most violet, purple and blue flowers, and also many red and brown ones, owe their colour to pigments - Anthocyanins - dissolved in the cell-sap. Anthocyanins occur in flowers, coloured roots and coloured stems as well as in the variegated leaves of some plants. When Anthocyanins occur in flowers they naturally serve to attract insects for pollination. Anthocyanins are capable of changing their colour which depends upon the reaction of the sap of the cells in which they occur. The colour is red when the sap is acid and blue when it is alkaline in reaction. When a coloured leaf is boiled in water, Anthocyanins are extracted and the leaf then appears greenish due to the presence of chlorophyll.

SOILS

We have discussed soils in previous Bulb Chats but because water and the mineral salts utilized by the plants are, almost exclusively obtained from the soil a knowledge of soils in its different aspects will always be helpful.

Soils are formed by the disintegration and decomposition of rocks due to weathering and the action of soil organisms, such as bacteria, fungi, earthworms, etc. Soils are also formed through interactions of various chemical substances present in the soil.

Physically, soil is a mixture of mineral particles of varying sizes - coarse and fine - of different degrees, some angular and others rounded, with a certain amount of decaying organic matter in it. The properties of a particular type of soil depend largely on the size of the particles it is composed of, and are determined mainly by the proportion of clay present in it. On this basis, soils may be classified into the following types :

1) Sandy soil, containing about 10% each of clay and silt with a large proportion of sand,

2) Clay soil, containing 40% or more of clay,

3) Loam, containing 30-50% of silt, a small amount of clay (5-25%), the rest being sand.

Sandy soil is well aerated, because it is porous. Because it allows easy percolation of water through large pore spaces between its particles it dries up quickly and often remains dry.

Clay soil, on the other hand, is badly aerated and it easily becomes water logged. Clay soil has a great capacity for retaining water because the particles are very fine. Drainage in clay soil is difficult. Clay soil is heavy, easily becomes compact, and cracks when dried up. Clay particles are mainly made of oxides of aluminium and are bound up with certain minerals, such as Potassium, Calcium and Magnesium. A considerable amount of plant food is, however available in clay soil.

Loam is the best soil for vigorous plant growth. It is porous for better aeration and for downward movement of excess water. It can retain water for a considerable time. Loam is rich in organic food.

Another important soil of the Western Cape is Calcareous soil. It contains more than 20% Calcium Carbonate. Calcium Carbonate is useful in neutralizing organic acids formed from humus. Calcareous soil is whitish in colour. This is also known as Limestone found near Bredasdorp as well as around Saldanha. Growing on this we find our Limestone endemics, such as Gladiolus caeruleus, Gladiolus miniatus, Freesia elimensis, Lachenalia muirii, Watsonia fergusoniae and Cyrtanthus leucanthus.

 

Back to Articles

Last Updated on Monday, 05 December 2011 16:31
 
Copyright 2010. Powered by Skytouch Media