Fertilizers and Bio stimulants By Jerry Naiser

In conversations with many people through the years, I have come to realize that there is a overall misunderstanding of fertilizers; what they are, what they do, why to use them, and when to use them.

First of all, fertilizers are not food. Plants make their own food through a process called photosynthesis, which utilizes the light from the sun, to create sugar from Carbon Dioxide and water. If you think plants are eating something, your right, it called sunlight.

Did you also know that the primary use of water, is for the transportation of nutrients from the roots, and that the majority of this same water evaporates from the  foliage. This process is called transpiration.

Have you ever wondered why it seemed a little cooler under that big Live Oak. Of coarse the shade helps, but one of the biggest factors is the cooling effect that water evaporating from the foliage has on the surrounding air.

 To be healthy, plants require sixteen nutrients, that are essential to their ability to live. These sixteen elements are the same for all plants. When a plant is deprived of any of the sixteen, the plant will become sick and die. This of course, rarely happens, because most of these nutrients are already present in the soil. There are times however when some of these nutrients are not present in large enough quantities or are not available because of the high PH of our soil, due to the large amounts of limestone in the soil, where we live.

This is where fertilizers and Bio stimulants come in.

Whets the difference between the two? Simple, fertilizers contain varying amounts of Macro nutrients, which are the three numbers that you see on the bag that you buy. These numbers represent (in this order) Nitrogen (N), Phosphorus (P), and Potassium (K). There are also very small amount of micro-nutrients.

Fertilizers generally contain large amounts of the Macro Nutrients, with very little Micro Nutrients, while bio-stimulants contain very little Macro-Nutrients, with a greater quantity of Micronutrients, and also  beneficial fungi known as Mycorhizae. This fungi works in a symbiotic relationship with the root system, drawing in moister and nutrients for the plant, and in return the plant feeds it carbohydrate

How do we use them

Of the sixteen essential nutrients, three of them (Carbon, Hydrogen, and Oxygen) are obtained from water and air. These elements are always available, and we do not need to be concerned about them. The other thirteen are almost always absorbed by the roots, for the plant.

The thirteen essential mineral elements obtained from the soil are divided into three groups, based on the amount of nutrients that are needed by plants.

The nutrients that are used in very small amounts are called micro-nutrients or trace elements. These include boron, chlorine, copper, iron, manganese, molybdenum, and zinc. Acid loving plants have trouble obtaining iron in Austin, because our soil is so alkaline.

The secondary nutrients; calcium, magnesium, and sulfur, are used in greater quantity and deficiencies are more common. Sulfur is often added to most good quality fertilizers that are sold for acid deficient soils, (such as ours) as a buffering agent. At Tree Masters, we add the sulfur our selves, to all fertilizers and bio stimulants we apply.

Nitrogen (N), Phosphorus (P), and Potassium (K) are the macro nutrients, that are necessary in the largest quantity. Although these nutrients are required in greater quantity, they are of no more greater importance than the micronutrients.

People tend to focus on these macronutrients, because of the great quantity that they are used.

Often times these nutrients, both macro and micro are in the soil, but are unavailable to the plant, because of over fertilization with products that have a  high salt content. Which brings us back in full circle to the importance of a soil test first, to know where you are, and where you need to be.

What does all this have to do with my trees?

Lawn fertilization is applied on the surface, and rarely reaches the root system of a tree. Furthermore, many lawn fertilizers actually contain a herbicide. These fertilizers are called a “Weed and Feed”. These herbicides are targeted towards broad leafed plants (weeds) The big problem here is that trees are also broad leafed plants, and these herbicides can cause fatalities in trees. Some trees, such as a Post Oak, will become severely ill after one application, while others, such as a Live Oak, can withstand many years, of repeated  applications, before becoming ill.

Trees are targeted by many defoliating pests. These pests can completely strip a tree in a matter of days. A healthy tree, has the ability to replace this damage, as well as fight other fungal and disease problems.

With out foliage, a tree has no way of feeding itself.

In the past few years, heavy rains, saturated soils , insects and fungal problems, have reeked havoc on our trees. This necessitates the use of all available tools that we have in our arsenal. To keep the remaining trees healthy. And let it be said, its harder to make a sick tree healthy, than it is to make a healthy tree Sick.

Test your soil, add the recommended fertilizer and/or Bio stimulant to your trees, in the proper amounts.

If you don’t have the time to do it, we can do it for you. Call me (Jerry), or E-Mail me: Jerry@RealGreenLawns.com