Major Factors That Limit Plant Growth

Light

• A plant that receives enough sunlight will be better able to produce the nutrients it needs to grow through photosynthesis. As sunlight decreases in winter months, so does photosynthesis and, therefore, growth. Of course, you can’t just place a plant in direct sunlight and expect success. The quality of light is just as important as quantity, and different plants require sunlight in varying degrees. Spring and fall flowering plants, such as poinsettias, are typically called short-day plants because they don’t require long periods of daylight in order to grow. Long-day plants, on the other hand, flower in the summer and will only bloom when they receive at least 12 hours of light daily.

Temperature

• Temperature plays an important role in whether or not a plant will grow; but as with sunlight, which temperature is right depends on the plant. Cool-season plants, for example, won’t bloom if temperatures are too warm. Alternatively, warm-season plants will go into dormancy if the temperatures are too low. Extreme temperatures can affect the growth and vigor of any plant. High temperatures may force plants to use the nutrients created by photosynthesis at a faster rate than they can be produced. In cold weather, photosynthesis slows down, as well as growth. In dormant periods, this is expected; but if temperatures drop unexpectedly during the growing season, this can affect both blooming and new growth significantly.

Moisture

• Water is a primary component of photosynthesis because it helps to ensure that the tissues remain firm and moves nutrients through the plant. Water also enables the roots to move through the soil and acts as a solvent for the minerals and carbohydrates that travel upward through the plant. Too much water, however, can essentially drown a plant. It’s important that your plants have enough water to complete photosynthesis but no more than that. A consistently wet environment can also encourage fungal growth, which may weaken or kill your plant.

Nutrition

• Nutrition refers to the chemical needs of your plant. Plants need carbon, hydrogen and oxygen in order to grow. These are easily found in the air and water, but plants also need six main nutrients that must be readily available for use. Nitrogen, potassium, calcium, phosphorus, magnesium and sulfur are taken up from the soil and provide the basis for a healthy-growing plant. In addition to these main nutrients, plants also need trace amounts of iron, zinc, manganese, nickel, molybdenum, boron, cobalt, chlorine and copper. These elements are crucial to plant growth, and most can be absorbed from well-fertilized soils. Different species of plants require varying levels of these elements, of course, but the first three are often required in the largest amount. Fertilizer supplements what might be lacking in the soil, but these elements are not readily available to your plant when they’re added and often must go through several changes before they’re usable.