Proper irrigation and fertilization in plant cultivation.
04-09-2025
15:49
After establishing the ideal environmental conditions your plants need using LEDWisdom horticultural growing fixtures, CO2 and climate control systems, the next steps will be pruning, repotting, watering, and fertilizing. Pruning and repotting are just as important as watering and fertilizing. This article will focus only on watering and fertilizing solid growing media (such as soil, coco coir, and rock wool). We will cover the details of hydroponic growing methods in another article. Growing media can be simply divided into two categories based on their watering and fertilization routines: firstly, media with high water retention capacity (of which there are many soil types), and secondly, media with very high air permeability, such as coco coir and rock wool. Working with media like coco coir and rock wool can be described as semi-hydroponics. The roots do not float in the water, but because the coco coir they are in has high air permeability, it allows for frequent watering, so they are never exposed to drought. Unlike soil, plant growing media like coco coir, which have high air permeability, need to be rewatered before they dry out completely. During the growing season, dividing the daily water and fertilizer needs of the plants into two waterings will increase efficiency and keep your growing medium constantly moist. For all growing media, fabric pots with very high air permeability should be preferred. The pots we use should have a tray at the bottom to collect drainage and allow the plants to be watered from below when necessary. When working with soil, after each watering, do not rewater or fertilize until the pot is largely dry to allow air to enter the soil. The most important advantage of soil is its regulating properties, while the advantage of hydroponic methods like coco coir is faster growth and larger harvests. When working with coco coir, as with all other hydroponic growing methods, pH and PPM should be measured with each watering. Keeping a record of the pH and PPM values of the water and fertilizer solution we are giving to the plants will help to quickly prevent potential watering and fertilization problems in the future for all growing media. The root cause of problems your plant is experiencing, but which you can't identify, may be due to pH and PPM levels being too high or too low. Depending on the problem, your plant may reduce or completely stop consuming water or fertilizer. In such cases, it's possible to identify the problem by comparing the pH and PPM values of the fresh solution you prepare for watering and the used solution that comes from the drain after adding this solution. Here's an example of what you should expect when your plants are healthy: For a coco-coir plant in its fruiting period, after applying a 2-liter fertilizer solution with a pH of 5.9 and 800 PPM, wait for the plant to consume the solution. After the next 2-liter watering with the same values, the pH of the solution that seeps into the tray and is available for the plant to use should be higher than when it was first applied, and the PPM should be lower. The plant should have consumed most of the solution and should release much less than 2 liters of water into the tray. As the water level decreases, meaning the plant is leaking less water into the tray, we can be sure that the plant is consuming water. If the amount of water flowing into the tray is 2 liters, it means the plant is not drinking any water, meaning the water level remains constant. Fertilizers mixed into the water have a low pH, and therefore, an increase in the pH value of the used solution collected from the tray indicates that the plant is consuming the fertilizers mixed into the solution. Similarly, a decrease in the PPM value indicates that the amount of particles in the used solution has decreased, meaning the plant is using the minerals and main nutrients. Unfortunately, plants experience growth problems if they are not properly watered and fertilized. Measurements showing a lower water level and PPM, and a higher pH compared to the initial preparation of the test solution collected from the tray, can be observed when your plant is properly nourished. In this case, the only intervention you can make is to try gradually increasing the PPM value in the new solutions you prepare for watering your plant. As the fertilizer dose increases, the plant's leaves should be carefully and frequently monitored, and if any yellowing or discoloration is observed, the previous PPM levels should be restored. In plants that are not properly nourished, water level, PPM, and pH values will change unexpectedly or remain constant in the test solution. The following list shows all possible change scenarios you might encounter in your measurements and the precautions you should take for each scenario. If the water level, PPM, and pH are all constant, your plant is neither drinking water nor consuming nutrients. In this case, ensure your PPM meter is working correctly and reduce the concentration of fertilizer applied to the plants. This will encourage your plant to start consuming nutrients and water again. If the water level, PPM, and pH are increasing, pH stabilizers in your growing medium may be raising your pH values. This is a common problem, unlike the constant water level, and as in the first point, it is necessary to reduce the concentration of fertilizer applied to the plants. If the water level, PPM, and pH are decreasing, your growing medium may have been washed with a pH below what is required, or too much CO2 may have been dissolved in the water. The solution is to use new media if possible, or if not, to re-water with appropriate values to eliminate the remaining low pH effect. It is also necessary to control the amount of CO2 pumped in. If the water level is constant, the PPM is decreasing, and the pH remains constant, it means the amount of nutrients in the growing medium is insufficient for the plant, and the plant is not consuming water. This problem can be solved by slightly increasing the PPM. If the water level is constant, but the PPM and pH are increasing, it means the amount of nutrients in the growing medium is insufficient for the plant, and the plant is not consuming water. The PPM can be slightly increased, and pH stabilizers that may be present in the growing medium should be considered. If the water level is constant, the PPM is decreasing, and the pH is increasing, the plant may be experiencing the effects of acid rain. Acid rain can be simply described as the withdrawal of minerals from the soil and the plant. To solve the problem, the pot should be thoroughly rinsed with plenty of water and fertilized with a solution with a higher PPM value. If the water level and pH are constant, but the PPM is decreasing, the plant is being nourished but not consuming water. To solve this, the PPM should be lowered, or if fertilizer accumulation in the growing medium is suspected, it should be rinsed thoroughly with plenty of water and fertilized with a solution with a lower PPM value. If the water level is constant, pH is increasing, and PPM is decreasing, the plant is in a similar state to that described in point 7, but to achieve the ideal condition, the PPM should be slightly lowered or the growing medium should be rinsed with plenty of water. If the water level is constant, pH and PPM are decreasing, the growing medium should definitely be rinsed with plenty of water. Afterwards, the PPM should be slightly lowered. If the water level is decreasing, pH and PPM are constant, the conditions are perfect. Maximum yield will be obtained without any changes. If the water level is decreasing, pH is increasing, and PPM remains constant, the plant is in a normal state. If no other adverse symptoms are observed in the plant, no changes are necessary. If the water level and pH are decreasing and PPM is constant, the growing medium should be rinsed with plenty of water and the PPM value should be changed. If the drain reading is 700 PPM (EC=1) or lower, the PPM value should be increased; if it is 9800 PPM (EC=1.4) or higher, the PPM value should be decreased. If the water level is decreasing, the pH is stable, and the PPM is increasing, the plant is consuming more water than nutrients, and the PPM value needs to be lowered. If the water level is decreasing but the pH and PPM are increasing, a situation similar to point 13 occurs, but the plant is in a slightly better condition than in point 13. Balance can be achieved by lowering the PPM value less. If the water level and pH are decreasing but the PPM is increasing, the plant may be under the influence of acid rain and is consuming more water than nutrients. To restore balance, the growing medium should be rinsed with plenty of water to lower the PPM value. If the water level and PPM are decreasing but the pH remains stable, it means the plant is demanding more nutrients. This situation can be considered ideal, and small increases in the PPM value can be tested. If the water level and PPM are decreasing but the pH is increasing, the plant is in almost perfect balance. Similarly, the PPM value can be slightly increased. If the water level, pH, and PPM are decreasing, the plant may be under the influence of acid rain but is still consuming water and nutrients. For a solution, the growing medium is rinsed with plenty of water, and the PPM value of the newly added solution is slightly increased. Our general recommendation for watering amount is to use water equal to 1/10 to 1/20th of the pot's volume. When watering your plants using the method described in this text, the likelihood of problems is very low. To obtain high performance from your plants, it is necessary to take PPM measurements while increasing fertilizer application and to constantly monitor them closely for any discoloration or deterioration of the leaves. To resolve any problems your plants may experience with their water and nutrient intake, you can restore your root zone to appropriate pH and PPM levels by using the measurement scenarios and precautions compiled above.