A question for the botany/biochem types: Where to prune for maximum branching?

[seedjar]

I have a rubber tree which I want to take cuttings from. Presently, it is a single plant which bifurcated at the base, so there are now two roughly parallel stems, one about 20" high, the other about 12". There is almost no "trunk" above the soil line, but they're joined by wood - it's not like the short one is a basal stem from the root system of the larger one. I believe that the shorter stem is a branch that formed after I rooted this as a cutting.
I want to know how I can prune this plant to make it branch as much as possible. Should I take the cuttings one at a time, letting the cut stem go to bud before shearing the other? Or should I take them at the same time? Answers with some sort of botanical/biochemical explanation would be preferred - I'm trying to get a grasp of the physiology involved. I know the specific details vary by species, but Hevea are important crop plants so I'm hoping there's a chance that someone has worked with them.
Anyways, thank you for appeasing my curiosity.
~Joe

PS - Erm, perhaps this is the wrong forum for this. If somebody with the power to do so thinks this belongs in Misc. Plants, feel free to bump it over. I'm really not sure since it's more of a general plant-culture question.

 

[Finch]

Auxins are a hormone that is produced by the leaves that affects branching. Strong tip or terminal growth makes a lot of auxin, and this suppresses the buds lower down on your rubber tree. If you remove one cutting, it will remove that hormone signal and allow the buds below the cut to break and grow... well, read this site for a through explanation. The hormonal effect of pruning like this is fairly universal (at least among the higher plants) and are not specific to any group.

This site will tell you everything you want http://www.evergreengardenworks.com/pruning2.htm

I would say taking a cutting and then taking another cutting from the resulting regrowth will make for a bushier plant. That way you are making two disruptions instead of one, so there are two times the plant will respond by branching.


Also, the common "rubber tree" in cultivation is not the tree that rubber is made from- the houseplant called rubber tree is a Ficus (fig) species (Ficus elastica). Do you know for certain that you have a Hevea? I did not know they were grown in pots or even available.

 

[seedjar]

Hmm, you may be right... I'm not sure, as the person I got the cutting from referred to it as a Hevea. It doesn't really look like other Ficus I've seen before, but I guess they're a big group. It does look like all the other houseplants I've seen referred to as rubber tree, so you're probably right.
So do you think there would be any difference in cutting both tips right now as opposed to just one? I know repeatedly cutting will produce more branches, but I'd like to get concurrent branches as opposed to recurrent ones, if that makes sense. I guess I'm wondering if there's a way I can prune to encourage the formation of many branches per cut.
~Joe

 

[Finch]

Well, both plants ooze latex when cut so it is understandable that they could get confused.

If you want a very bushy plant, I would say take cuttings from the one of the tips now, and then take cuttings again from the resultant branching re-growth as well as the other stem, but I doubt it will make a very big difference either way. If you want a really bushy plant and don't mind slower growth, place those rooted cuttings in the same pot as the parent plant. The bushy rubber trees you see in stores and what not are often not one but several cuttings planted togeather in the same pot. Crowded, yes, but dense and attractive.

 

[herenorthere]

Does it have a noticeable dormant season? Using fruit trees as an example, since I know more about them, there's a world of difference between pruning in the dormant and growth seasons. Dormant pruning encourages wild vegetative growth and is what leads to water sprouts, those fast-growing vertical shoots that don't bear fruit. Summer pruning, on the other hand, encourages compact growth and (in apples, pears and the like) the formation of fruiting spurs that produce fruit for years. You aren't looking for fruit, but there could be a big difference depending on what part of the annual growth cycle you prune.

 

[seedjar]

It certainly slows down in Winter. So I should prune in Summer for bushier growth, then? It's already in the habit of growing straight up.
~Joe