Thursday, October 22, 2009

Ficus burtt-davyi - African species for bonsai. (All pictures will be updated by better ones when they become available.)

This is the second species I'm going to discuss as part of my effort to promote African species as bonsai.

 Ficus Burtt-davyi thickening of the trunk using the trunk splitting method.
I have used these three trees for a group planting in June 2009:

The grouping:
But I never thought they would grow so slow! From the time I have grouped them I almost broke up the planting because growth was very slow! The last growing season the trees grew a little bit faster.

I have only pinched back growth on a regular basis and did not do any further styling. It seems that the trees are settling now and I can do some styling next summer.

The stones are temporarily there to keep up the two smaller trunks.

The trees today:

 In general I have found this species not a good candidate for bigger bonsai. The variety is actually a rambler and massive trunks are not found in nature. I also do believe that I am keeping this variety too wet because in nature they grow on dryer mountains/cliffs, rooting where ever the rambling shoot touches ground.

The best bonsai of these I have seen is less than 15cm tall.
(Will update on this one in summer.) 

The ramification and reduced leaf size possible with the form "Nana"

DESCRIPTION: This is another African tree that lend it well to the art of bonsai. This mostly evergreen tropical tree(It will shed it leaves in periods of drought and cold or when the tree is subjected to other sudden eviromental changes) is fast and easy to grow under a wide range of conditions(It will not tolerate temperatures below freezing).
Luckily the trees recover well after a "human induced" drought:
Notice the new leaves.

The smooth bark of this Ficus is white/grey/silvery in colour and contrast nicely with the dark green leaves.
 The bark on the bigger leaf form:
The leaves are simple, alternate, elliptic to obvate in shape with the basal pair of veins forming a characteristic "V".
The V on the underside of the leaves of the bigger leaf form:

The young leaves are sheathed in reddish brown stipules that add a ruddy colouring to the plant in certain seasons. 
The shiny leaves of the "Nana" form:
The species forms aerial roots quite easily:
Notice all the aerial roots on the trunk and some of them growing up the rim of the pot. These roots can be left to thicken up for a nice Banyan style bonsai.

The tree can be propagated by seeds but it needs a specific wasp to fertilize the seeds. Seeds outside its natural range will not be fertilized. The best way to propagate this tree is by cuttings. Thick cuttings will root easily but even the smallest parts with a leave and a bud will also grow. It is a good thing to let the cuttings dry out a bit before planting them - this prevents the cuttings from rotting.

DISTRIBUTION: Restricted to south-eastern areas of South Africa and extreme southern part of Mozambique. Coastal forest (strangler growth form), coastal dunes (on sand, exhibiting salt tolerance), or thicket & savanna (where the species is usually associated with rocky outcrops or cliffs, often a "rock-splitter", growing as a shrub or small tree).

This species is variable also in leaf size and shape. The form "Nana" is usually used for bonsai because of its leaf size. This form's leaves will reduce to 5mm and even less.

REPOTTING: Repotting is done when the tree is actively growing, the best time being the warmest time of the year. Heavy root pruning may be done as long as the top is reduced too. Big yamadori, even big trees take also well. Keep the transplanted trees in shade until the tree starts to grow. Collected material can be left in light shade for a full growing season. Be warned- doing major work in colder weather can lead to branch die back, root rot or losing the whole tree!

POTTING MEDIUM:It can grow in a variety of mixtures as long as it is free draining. I use 20% gravel, 40% washed river sand, 20% palm peat(a long lasting organic fibre obtained from the Cantonese's palm.) and 20% other organics like composted bark.


The tree was last repotted three years ago.

 Definitely in need of a repot. A Big root is encircling the inside of the pot and the medium has lost it's integrity:

Koos Robbertse, who is blind and the owner of the tree trying to remove the build up of chemicals on the pot:

The root that need to be removed:

Koos's mother, Tannie Martie, holding up the removed root:

 Some soil raked away. He did not want to bare root the tree because of the big root removed. Normally he defoliate his Ficus when he do heavy root work:

A new layer of soil was placed on the bottom of the pot:

The calcium buildup could not be removed. Because he did not have another pot in hand he went forth with the potting up. He would let the tree recover for three months in the pot before he will clean it up using vinegar
The tree placed on top of the new medium and some roots rearranged. koos made sure that the tree was placed correctly in the pot - just off center and the apex coming to the front.

The tree correctly placed ready for the rest of the soil. he used wooden chopsticks to help the soil settle. He did not water the tree immediately - the following day he would submerge the tree in a bucket for 5 minutes.
Well done Koos!

STYLES: Root -over-rock or clinging to rock suits this tree very well.
Here is an example of it growing in it's natural habitat:

Three year old cuttings - typical growth pattern if let alone:

As the leaves reduce very well, the tree can be grown in any style. The tree can even be grown in a cascade as long as the higher growth is pinched regularly. The tree looks good in an open umbrella Ficus style. The Banyan style suits this tree also well because it will form aerial roots easily.

STYLING:The tree back bud easily especially after heavy pruning. Styling is mainly done by wiring but bending thick branches can be done by splitting, hollowing, notching and drilling. The bark is quite soft so wires much be checked regularly.As this tree has mostly a smooth bark wire marks stay for very long. For small wounds I only use flowers of sulphur but big wounds must be sealed to prevent the tree from drying out. Taper can be achieved by sacrifice branches and by the trunk splitting method. The first buds on a healthy tree can be pinched after every second leave to reduce the size of the leaves. Defoliating is not necessary to reduce the leaves, but can be done to help with the ramification of the branches. Growing the tree indoors or with to much shade will lead to longer internodes and bigger leaves. Branches fuse very well so big trunks can be achieved by fusing cuttings.

WATERING AND FEEDING:When actively growing the tree is quite thirsty. In spring, summer and autumn keep the tree uniformly moist. In winter the tree still needs water but just enough not to dry out. The tree responds well to organic or inorganic fertilizers.