Sunday 27th February: The environment changes seemed to have happened without any great catastrophe although I could see no improvement in the condition of the trees. I am beginning to think they may have root rot which is the disease that the Moringa Oleifera trees are known to be susceptible to. Root rot does kill the plant. The study was busy so I have to wait until Monday to do as much as possible to better the condition of the trees. I intend to carry out a proper examination of the soil and roots, decided whether to flush or bottom water the trees, add a fan to improve air circulation, and, possibly, add a height extension to the environment. Bottom watering is an attempt to water the tree through the dishes that the pots sit on. The advantage to this is that it may encourage the tap root to develop strength as it drills down to find water. Flush watering is more or less giving the tree a shower by pouring large quantities of water through the soil; a kind of cleansing. This is a common procedure with many plants and I have done it with a lemon tree. However it is very risky and I think it may do more damage than good.
Air circulation is important. A fan may make the trees stronger as the roots develop strength as they gain strength from counteracting the wind.
Monday 28th February: Arriving early at Nottingham Contemporary I quickly checked humidity and temperature in the environment (46% humidity and 27.7 degrees Celsius (81.86 degrees Fahrenheit) at top soil level. The trees had dropped a few more leaves but less than I had expected. I think the connection of light to heat is working.
I dismantled the environment casing and removed the trees. The first thing I did was set up a fan and positioned it facing the trees. This was the first strong air movements that the tree had encountered. As I previously mentioned the trees gain strength through counteracting the force of the wind. The sight of the trees outside of the environment blowing in the artificial wind was really compelling.
I had brought with me a moister meter and a pH soil reader. As expected the soil was very dry at its base, slightly moist in the middle section and dry at the top. I gave each tree 4 fluid ounces of water which I poured into the base tray of each pot. Several hours later, on re-checking the moist reading, I repeated this action giving a total of 8 fluid ounces of water that was bottom fed.
The pH reader gave a reading of some 6.5 which is slightly over alkaline for the Moringa Oleifera trees. Moringas prefer a slightly acidic soil at approximately 6.1- 6.2 pH. I carefully removed some of the top soil manure at both surface and at the edges of the pot and replaced this with acid based compost. I hope that this will, in combination with the other soils, make a better soil for the trees. I also gave this new top soil a light watering of about 1 fluid ounce per tree.
I had bought a small desk top fan to install in the environment but struggled to fix it into position. I plan, as a temporary measure, to install it outside the environment adjacent to a lower open vent. Finally I placed the trees back into their environment and increased light hours to 14.5 hours a day (5.30 am – 8 pm). This may seem a lot of hours but these lights can never replicate the power and intensity of sun light. In hydroponics terms it is considered that 12 – 14 hours a day is a vegetative growth similar to a winter state. I do not want to push these trees so have gone for duration slightly above the edge of vegetative growth.
Tuesday 1st March: The trees have deteriated a little. I did expect this after the watering and soil changes of yesterday. The environment was steamed up and the humidity was 75%. I also expected this and was able to open the vents and use the fan to quickly condense the water vapour and bring the humidity down to 48%. These are early days after the changes, which I believe were necessary, and I need to keep observing for at least a few more days before making any new decisions. I have prepared the grow tent in my studio to take a couple of trees for intensive care, if necessary.
I set up the small desk fan adjacent to a lower vent and set it to run for 15 minutes 3 times a day at 4 hourly intervals (10 am, 2 pm and 6 pm). The 15 minute duration may seem short but the fan does lower the temperature of the environment and I want to try to keep a balance between air circulation and temperature build up. The 4 hour gap is sufficient for the environment to regain its heat.
Wednesday 2nd March: This morning the trees seemed little changed. The environment was at a slightly low temperature of 23 degrees Celsius (73.4 degrees Fahrenheit) with a humidity of 46%. I think the low temperature is due to a combination of the evening cooling and the affect of the fan. I dismantled the environment casing and inspected the trees. The top soil was surprisingly cold and wet. I thought this may happen and had brought with me a hair dryer that I have used before on over wet top soil. With each tree I removed a little of the wet soil and replaced with soil that I had constructed in my studio and that I knew was pretty dry. In between doing this I used the hair dryer to gentle raise the temperature in the top soil.
I also adjusted the light hours to 15 hours a day (5.30 am – 8.30 pm). This was both a plan to try and bring on growth but also to reduce the time to 9 hours when the light and heat is switched off.
I placed the trees back into their environment and left whilst the temperature was slowly building. I plan to return later in the day to see how the temperature, humidity and trees are doing.
I returned to the study. The temperature at soil level is 28 degree Celsius (82.4 degrees Fahrenheit) and the humidity was at 47%, both of which are good. The trees seemed relaxed for the first time in a couple of weeks.
Thursday 3rd March: Much the same this morning with environment well balanced and the leaves on the trees appearing flat and smooth; an indication of less stress. I am now sure that running the heat in synch with the lights has been beneficial. I am also sure that capillary action feeding is the best solution to watering in an artificial environment that is heated from a base plate.
I checked the soil conditions of all the trees. Whilst there were variations the soil was generally moist throughout its depth. The earlier problem of having trees growing in soil that was very dry at its base, wet in the middle and dry on its surface has been addressed through the bottom feeding. The pH balance is now at 6.3. This is very near to the ideal, slightly acidic soil that the Moringa Oleifera tree prefers. The introduction of a layer of slightly more acidic soil has changed the pH balance.
I am concerned that the leaves are still yellowing and growth has all but stopped. For this reason I decided to check for root rot in the sister plants I have at my studio. These are 3 plants that looked very weak after 8 weeks of growth and were removed from the environment and placed next to the glass window in the study to see how they reacted to natural light. In week 11 I moved them back later to my studio for further study. In the studio they were placed into a large grow tent and given fairly ideal conditions of temperature and light. These were very weak plants but had experienced all the stages of soil change and watering as the trees in the study. My point is that I can use one of the weakest of the trees to see if it is suffering from root rot.
I carefully pulled the small tree for the soil and washed its root system. I was looking for discoloured and blackened roots. The roots were underdeveloped; a problem identified from early in the trees growth. I also found some evidence of the blackened roots that indicate root rot or a root virus of some kind. For this reason I washed the roots and changed the soil of all three trees and will observe them over the next few days to see if this radical intervention improves their wellbeing. If the test trees react well to this treatment I will apply the same action to a couple of the trees in the installation.
Friday 4th March: A few more yellowing leaves this morning and little sign of new growth. I removed the yellow leaves in order to try to get the tree’s energy to go to the good growth. I also carefully removed each plant from its pot in order to small the roots. On of the indications of root and soil problems is that the roots and surrounding soil smalls bad. I am glad to say that each tree had a fine fresh, almost scented smell to them. This was a radical intervention but needed to be done. Whilst pocking around in the soil I was able to ascertain that the soil was fairly moist, which is good, but much colder than I expected. If the roots are fine then it may be that the problem is a combination of cold soil that has been very wet for a few day in week 11. I also noted that a couple of the trees had very well developed tap roots whilst a couple more seemed not to have properly developed a tap root. This could be explained by the early soil being very dry at its base and consequently the tap root drilling for water would not go towards the bottom of the pot.