In fall 2016 I received a gift from a friend of mine, a bhut jolokia pepper plant, also known as “ghost pepper”. It was about 40 cm high, grown in a hydroponic system that resulted in a very dense root system, growing very vigorously. My idea was to transform this pepper plant into a bonsai, into a so called “bonchi”. I reduced the height of the plant to about 15 cm and cut all the leaves, branches and fruits. Only the trunk remained, prepared to grow new branches in the desired positions. After hard pruning the pepper, I reppoted it into a small green glazed bonsai pot that I have bought some time ago. You can see in the image below how the plant looked after finishing the pruning and reppoting in fall of 2016.
Over the winter I kept the plant indoors in a room with direct sun and temperatures that did not drop below 20C. The pepper responded well to pruning and reppoting. In only a few weeks new growth started developing on the trunk. I took good care making sure that the soil never dried out. I continuously fertilized it every other week with liquid fertilizer (NKP 6-5-6). By spring 2017 I had to prune back the new branches as those grew quite long. Also in early spring of 2017, the leaves were too many on the plant and light could not reach the trunk anymore. So, I considered to partially defoliate the entire plant, leaving only the small leaves untouched. As the days became longer, warmer and with more sunshine, the plant started growing very fast. It also developed many flowers that I manually pollinated using Q-tips. Due to direct sunlight, fertilization and continuous watering, the plant developed a dense branch structure with long new shoots filled with many peppers. By August 2017 the plant looked like in the image below. Due to long growth and many peppers it was necessary to wire the tree to the pot, otherwise risking it to fall over.
The white spots that are visible on the leaves are because few day prior to taking this picture I sprayed the plant with fungicide. I do such treatments at least once a month to prevent diseases. When I potted the three in the green pot, I saw long roots that I did not prune back at that time. It was back then when I decided that at the next reppoting of the three I will do a root over rock project and take advantage of the long roots. The time has come and in the followings I will present all the steps that I performed for this project. First thing was to collect all the peppers from the three. The bhut jolokia is the 7th hottest pepper in the world according to the Scoville scale. It is more or less comestible as it gives stomach ache even when consuming small amounts of the fruits.
The harvest from only this small three was a dish plate full of peppers. Not all of them reached complete maturity so I had to collect them green. However, I will expose those to direct sunlight and they will turn orange, just like the rest of them. The oldest fruits will be dried to collect the seeds to germinate them in early spring next year. After harvesting the peppers, I pruned back the three quite hard and also cut all the big leaves to let the light to enter and reach the trunk.
I removed the wire that kept the three in vertical position and proceeded to the actual reppoting process. When getting out the tree from the pot, it was quite root bounded on the bottom side as expected due to the excessive growth that I spoke about earlier. The entire root system came out of the pot like a brick as you can see in the image below. On one hand, this is good because for the root over rock project I needed long roots to cover the future rock, but on the other hand untangling and combing them without breaking the fine feeder roots is quite a challenging process.
However, I started gently removing the old soil and combing the roots in a radial shape. I gave them a good wash with fresh water and combed it again, placing the roots properly to emphasize and to get an image of how those will settle over the rock.
There are many fine feeder roots all over but there are also some long thicker ones that will be useful to cover the rock. I also removed feeder roots that were growing in wrong directions or too close to the main trunk. Unfortunately, as you can see in the image below, the bark of the three on the bottom side rot away because a lot of lime was deposited on it as I water my trees with tap water. This held back moisture and kept the bark wet all the time. I cleaned the lime away together with the bark. In the future I will periodically perform washing with vinegar diluted in water to make sure this will not happen again. I hope that in time, new bark will form and slowly the reverse taper will disappear.
The rock that I have selected to use is a mountain rock that has a hollow exactly where the bottom of the trunk is positioned in the image below. This helps a lot to find the proper position for the tree. The thicker roots will be placed into their final position along the rock in all directions. To keep them in place, I tied them with natural raffia. The benefit of using this instead of artificial raffia is that in time it rots away not cutting into the roots when those will thicken. I placed all the roots in the position ensuring that all are growing their feeders downwards to the bottom of the pot under the rock.
After fixing the roots with raffia, I wrapped around the rock and the roots transparent plastic material used for kitchen purposes. This creates a cavity that I will fill up with fine sand to ensure that all the roots that covered the rock will be keep moist and in the same time it will prevent them to grow to the sides, forcing them to develop downwards. After wrapping the roots, I potted it into a bigger pot making sure that soil fills all the gaps under and around the rock. The soil composition that I use is the same for all my trees. I spoke about how I drill my pots and how I mix my soil in an earlier post that you can read here.
After filling the pot with soil and fixing the tree in the correct position using thin wires, I filled up the wrapper with fine sand. Using a chopping stick I worked it around the wrapper to make sure that it fills all the gaps on the lower sides of the rock. Using water also helped a lot as the sand easily flows into the right position. Finally, a good watering ensured that the sand is in place and moist and the soil on the outside of the wrapper is also wet and ready to accommodate the roots.
In a few months I will gently remove the plastic wrapper and the fine sand, but only after I will see vigorous growth on the branches. This will tell me that new roots are also developing in the soil so I will be sure that the removal of the wrapper and of the sand will not harm the tree. When removing the sand I will also cut away all the fine feeder roots that will eventually grow in the visible sides of the rock. This will promote only the roots inside the soil to develop. At this moment half of the rock is inside the soil. The goal is that in time I will lift the rock over the soil entirely. However I will keep you updated with future posts.