With gardening, there are only so many things that have an effect on plant growth. In other words, there are only so many things that can go wrong. Together, these things are known as growth influencing factors. Having a thorough understanding of each growth factor in your garden gives you the ability to identify and correct less than perfect conditions in your garden area before they become a problem.
In order to get the greatest benefit from this information, you need to understand your indoor garden will only be as successful as the least perfect factor allows it to be. It only takes one factor to be out of the acceptable range to cause a problem. Knowing the ideal range for each plant growth factor and having the ability to keep each and every factor within it’s ideal range results in maximum plant growth and maximum yields.
When a problem of unknown origin occurs, the growth factors list becomes a priceless tool. By checking conditions in your garden area against a list of growth influencing factors from top to bottom, you can identify the source of any problem. The growth influencing factors you need to consider in every garden are…
Time- You have no control over time itself, but you have to understand the role time plays on each of the other factors. When growth factors stray outside of an acceptable range, the amount of damage is dependent on time.
Temperature- Most indoor plants will do best when grown at temperatures between 70 and 75 degrees. Many factors, such as temperature preferences, will differ slightly from plant to plant. Humidity- Most indoor plants prefer 50% humidity, plus or minus 10%. Some plants, like orchids, prefer higher humidity. Other plants, like fruiting tomatoes, can experience end rot from humidity that is too high.
Water- The water you begin with should have no more than 150 parts per million (ppm) carbonates and sodium. If the tap water in your area is not acceptable, you can either install a reverse osmosis filter or use distilled water.
Light- Most fruiting and flowering plants require relatively strong lighting (50-80 watts/sq.ft.). The same plants, however, will grow fine vegetatively under 25-40 watts/sq.ft.. Some houseplants have even lower light requirements. The stronger the light, the more food the plants will usually require.
Nutrition- The most complicated of all the growth influencing factors. Plant nutrition consists of primary nutrients, secondary nutrients, micro-nutrients, hormones, enzymes, carbohydrates, and other things. Not only are the nutritional requirements for each plant different, but the nutritional requirements for individual plants change as they go from the seedling stage, to the vegetative stage, and finally into the flowering stage.
pH- If you are growing African Violets or Venus Fly Traps you may need an acidic soil, but most plants flowering and fruiting in a garden prefer a “sweet” soil (slightly alkaline). This is because 98% of the plants on earth have formed symbiotic relationships with beneficial micro-organisms, and these organisms survive best at a pH of 6.2-6.5. O2- Plants require oxygen in the root zone. Nutrient absorption only takes place in the presence of oxygen. That means if you over water, your plants will not be taking up any nutrients. This is the reason for having an air bubbler in your nutrient reservoir. It is also one of the reasons you get accelerated growth rates from aeroponics. CO2- Carbon Dioxide is to plants as oxygen is to people.
At the center of every plant cell is a carbon molecule, taken mostly from atmospheric CO2. In fact, if all other growth influencing factors are in their ideal ranges CO2 becomes the plant growth limiting factor. Well maintained gardens have reported 50% increases in yield with the addition of CO2. Pests- Pests include insects like mites and thrips, but it also includes pathogenic micro-organisms. These microbes are the cause of stem rot, pythium, fusarium, and other garden nightmares. Many of these pests are very, very small. It takes careful inspection of your plants to eliminate this as the possible source of your problem.