Healthy Plants 101

Growing Healthy Plants

Knowing a plant’s cultural requirements is half the battle in successfully growing it to its full potential. Implementing those requirements is the other half.

Know your plant

When adding new plants to your landscape or potted plant collection it is a good idea to do some research.  Great resources include popular gardening and botanical garden web sites. Your local extension service offices are another reliable source of information.

What does it take to grow your plant successfully?

Moisture - It is important to know what amount of water a plant prefers in the soil as well as the level of humidity (air moisture).  Does the plant’s water need change seasonally? Seasonally dry growing plants need a dormant period to flower.  Examples of plants that require a dry period to flower well are Jacaranda and Royal Poinciana trees.

Water quality - The quality of water used to irrigate can have an impact on everything from thriving and growing, to setting bloom. If the pH of your water is too high or too low, or contains too much chlorine or calcium, some more finicky plants could fail to thrive.   Water plants such as orchids, ferns or carnivorous plants using rain water or distilled water.

Light - Some plants prefer full sun; others prefer shade, partial shade, or shade in the afternoons to keep from burning foliage. Some plants require a certain number of hours of sunlight to successfully bloom, others need longer nights (more hours of darkness) to trigger bloom. Correct light levels are critical for successful plant culture.

Soil - Some plants like sandy soil, others prefer soil mixes heavy in organic materials, some prefer no soil at all (epiphytes). Organic potting mixes can break down over time and need to be replaced every year or two.

Temperature - Some plants like it hot, others prefer cooler temperatures, some need warm days and cool nights to flower or set fruit.

Nutrition - Some plants are “heavy feeders” and the soil may not contain enough of the essential minerals they require. They need regular applications of fertilizer to be successful. Other plants can handle fertilizers only in very small amounts on a frequent basis, otherwise they may become stressed or burned. Many plants will fail to thrive if a particular mineral requirement is not met.

Air Circulation - Plants grouped together too closely have no room for air flow around the leaves and blooms. This could lead to fungal and bacterial infections or create a cozy home for certain types of pests.

Liebig’s Law of the Minimum

Liebig's Law of the Minimum, often simply called Liebig's Law or the Law of the Minimum, was a principle developed in agricultural science by Carl Sprengel (1828) and later popularized by Justus von Liebig. It states that growth of a plant is controlled not by the total amount of resources available, but by the scarcest resource (the limiting factor). It was found that increasing the amount of plentiful nutrients did not increase plant growth. Only by increasing the amount of the limiting nutrient (the one most scarce in relation to the needs of the plant) was the growth of a plant improved. This not only applies to nutrients, but also to all of the other needs as well (Soil, Water, Light, and Temperature) if one of these needs is not met, it becomes the limiting factor.