Fabric Garden Planters
The research team found six statistics to examine the strengths and weaknesses of fabric and plastic containers. The six statistics include growth index, shoot length, dry weight, water use efficiency, root zone temperature, and rootball.
PLANT GROWTH INDEX
- Plant growth index was calculated as (height + width 1 + width 2)/3 in a research project about plant growth. The height is measured from the rim of the container to the highest point of the plant, width 1 is a measure of the width of the plant from north to south, and width 2 is the width of the plant from west to east. Fixed pot labels maintain orientation for the measurements to be consistently taken.
- In the same research project, the average final plant growth index for plants grown in plastic containers was 14.9 and fabric containers was 12.4. The plant was boxwood grown in Texas and they were watered 500ml daily.
- The research project results show that the boxwood in the fabric containers was smaller than the boxwood in the plastic container, not including roots. Therefore, if an individual wants to grow smaller plants, fabric containers are suited for that goal.
- A research project found that in Kentucky, the shoot dry weight for plastic containers was 11.9, while the fabric containers was 10.5. In Texas, the shoot dry weight for plastic containers was 11.8, while the fabric containers was 8.6.
- Dry weight measurements are more reliable as the water content in a plant depends on the water content in the environment, according to this article.
- These values found in the research project indicate that the plants in the fabric containers were smaller than the plants in the plastic containers, based on dry shoot weight. This could be beneficial for individuals wanting smaller plants, as then they can use fabric containers to reach that objective.
WATER USE EFFICIENCY
- According to a research project, in Kentucky, the water use efficiency for boxwood plants in plastic containers was 0.7, while the plants grown in fabric containers had an efficiency of 0.5. In Mississippi, boxwood plants in plastic containers had an efficiency of 0.8 and fabric containers had an efficiency of 0.6. In Texas, boxwood plants in plastic containers had an efficiency of 0.8 and fabric containers had an efficiency of 0.6.
- The experimental study from HortTechnology also found that fabric containers' leachate electrical conductivity was lower and the leachate pH was higher during most of the season.
- The experiment concluded that the fabric containers were more porous and tend to lose more water. This means that fabric containers have reduced water use efficiency that causes a reduction in electrical conductivity and a more basic soil environment.
- Electrical conductivity is directly related to fertilizer level. Following the conclusions from the experimental study, it is clear that fabric containers lose electrical conductivity and fertilizer due to their porous fabric.
- The optimal pH for plants is 6.0-7.0, which is acidic to neutral. With fabric containers, based on the research study findings, the porous fabric allows hydrogen ions to leave the soil, creating a more basic soil environment that is not optimal for most plants.
- Overall, based on the research study findings, fabric containers have lower water use efficiency due to porous fabric, which impacts the pH of the soil, electrical conductivity, and the level of fertilizer.
- An experiment conducted by Texas A&M University found that when Rosa L. x 'Radrazz' was grown with pine bark substrate, it had a shoot length of 50.6 cm when grown in plastic and 114.5 cm when grown in fabric.
- As the experiment results indicate, this particular rose variety flourishes in a fabric containers with pine bark substrate, compared to the rose variety grown in the plastic containers.
ROOT ZONE TEMPERATURE
- In the same Texas A&M University experiment, the root zone temperature of Rosa L. x 'Radrazz' grown in fabric was 36.0°C for pine bark substrate and 36.7°C for peat moss substrate. The root zone temperature for the same plant grown in plastic was 55.6°C for pine bark substrate and 54.3°C for peat moss substrate.
- The optimal root zone temperature is 70°F, plus or minus 5 to 10 degrees Fahrenheit. The equivalent optimal root zone temperature in Celsius is 21°C, plus or minus 3 to 6 degrees Celsius.
- Given the optimal root zone temperature and the experiment results, plastic pots do not offer optimal conditions for the plant's roots as compared to fabric containers.
- A research experiment found that the surface of rootball of the Rosa L. x 'Radrazz' covered by deflected or circling roots in fabric containers with pine bark substrate was 8.3 cm and 3.5 cm in fabric containers with peat moss substrate. The equivalent results for plastic containers were 42.5 cm in pine bark substrate and 22.3 cm in peat moss substrate. (Source 2).
- According to an SFGate article, when roots begin to deflect and then circle around, they may compress conductive tissues at the base of the plant, preventing the transportation of water and sap. This can damage or kill the plant.
- Given the research results on rootball, growing plants in plastic containers may lead to plant damage due to circling roots, while fabric containers may help prevent circling.