April 4, 2016
Everything you Want to Know About Harvesting Good Bamboo, and More
Boo master craftsman James Wolf discusses the lengths to which he and his team go to produce frame-worthy bamboo tubing.
Where does the bamboo grow, and what kind is it?
The younger plantation is on land that we own and currently supplies our chain stays and seat stays. Specification for these parts is hard-to-find, so it’s good that we are growing our own. The primary plantation is one that we have been managing for about seven years and provides the poles used in our front triangles. It’s very healthy and produces some of the best-quality bamboo in the world.
The species is Tam Vong, also known as Iron Bamboo. Of the 2000 or so different species of bamboo in the world, its quality is far above the rest.
What maintenance does the bamboo require?
The main requirements include basic watering, trimming, and groundwork. It’s important to make sure that it doesn’t get dry in the first year or two after it’s been freshly planted. Any broken or unhealthy poles should be removed from the clump so the energy goes into the strong ones. Fallen leaves get swept to the base of the bamboo to maintain moisture and provide nutrients for the plant.
What time of year do you harvest the bamboo, and why?
We usually harvest over two months around January. This is the dry season, and there’s some slowing down and collapsing of the structure of the plant. At this time there will be lower starch levels in the plant, and it will be harder and drier. It’s the best time of the year to harvest, because the poles are the best quality.
Tell us about the harvest–how it works, and how you select which poles are ready?
The harvest at our primary plantation is an adventure expedition. We all go out together, about a dozen of us. We bring tools as well as lots of camping supplies, as we will spend a few days in a row on the plantation. We set up a camp and sleep there for about four or five days while harvesting.
Only mature poles are harvested–we can tell the age by the surface characteristics and the color of the culm. 3 to 3 1/2 years is just right. Any younger than this and they don’t have the strength. Any older than this and they become lighter and more brittle.
What equipment or materials are required for the harvest?
There are two basic tools. One is a handsaw; I prefer a Japanese-style pull saw. The other tool is a Vietnamese hatchet that is shaped like a sickle. We use plastic twine to tie the poles in bundles. Then there’s all the camping, cooking and survival gear.
How is a pole harvested?
The plant needs to be assessed carefully, and we need to look for suitable poles on the plant. A plant might have say 25 poles growing out of one clump; I may find two [poles from that clump] that I like. Every case is unique. They have to be mature, good color, no decay, and the right diameters that we need for bicycle frame making.
We’ll cut it at the base with a handsaw or a large chisel and mallet. Is important to cut them as close to the ground as possible because it’s healthier for the plant. It’s so different from a tree; you cut a tree one time and it’s gone. When harvesting our bamboo, we’re mindful about the overall health of the plant. The healthier it is the better quantity and quality you’ll get in the future.
The bottom end of the pole is then lifted off the ground, and you walk away from the plant with it, eventually the foliage up top will become clear of all the other foliage, and when you’re far enough away from the plant, the top end will fall to the ground.
The very bottom of the pole does not have any lateral branches from about midway up to the very top, every node has lateral branches going in alternate directions on each node. There’s a main branch, and two smaller branches on either side of the middle one. The lateral branches are chopped off with the sickle shaped tool or a handsaw. We have to be careful not to damage the surface of the culm while cutting off the branches.
Poles are then carried from wherever they are cut on the plantation to a loading zone. It’s most efficient if we put five or six poles together in a bundle, and then have one person at each end to carry them through the forest.
How does the remaining plant/culm respond?
The capillary action of transpiring water up the plant continues for a few hours, and the top of the fresh-cut area will have some water moisture for about a day. It will then dry up, and energy will go elsewhere in the plant.
What happens to the poles next?
When we have harvested enough for a truckload and it’s bundled and ready to be loaded, we will load the bundles onto the truck for transportation for pole processing at our bamboo farm. For the harvest that happens on our own farm, it’s a bit less intense. A couple people can do the harvesting over the period of a few weeks, and the poles are simply hand carried to the processing area of the farm.
Green poles are straightened over heat on a straightening apparatus. They are worked through the hot zone and leveraged on two lateral arms. As the Bamboo heats up, it will hit a specific temperature where it’s elasticity kicks in. At this point it’s easy to bend and straighten the pole. It’s flexed in the fixture, and pushed through in increments until the entire pole is straightened.
The poles are then tapered. They are about 2 inches at the big end, and 5/8 of an inch at the small end. We must select portions of the pole that are suitable for top tubes, down tubes and seat tubes. These are cut to length with a chop saw, and then sun-dried. We rotate the pieces in the sun to dry evenly, during this process their color will change from green to tan.
How do these harvest procedures affect the quality of the bamboo?
With regards to the quality of the bamboo, I suppose there are two factors. One is the quality of what we are now harvesting, including age and growing conditions. The other thing is how we are maintaining the plant for the future harvests.
What do you enjoy most about the harvest?
I would say that the greatest satisfaction happens on the farm, because I’m now able to build bike frames from bamboo that I actually planted in the ground myself.
Tell us some interesting facts about the harvest?
It does sound like a lot of fun here, but in actuality it’s pretty tough. The humidity and the temperatures are extreme, there’s mosquitoes, scorpions, deadly centipedes, and other strange bugs. We also have a variety of snakes and a whole bunch of smelly men camping for five days. It can feel pretty awful to be hot, stinky, and wet for five days. Sometimes we eat “jungle meat” for dinner, which is anything that the guys catch or hunt during the day.
Another fun fact about the harvest is that it’s the same group of us that are carpenters in the factory making bikes. It’s a break from our usual environment, and there’s good camaraderie, even though it’s physically quite demanding.