How to feed your bonsai (Part 1)

Rod Smith has shared his knowledge with us and now it is time for you to learn from the master.

Let's start by learning the basic concepts about the nutrients, and then we will learn how, when and why to use them.

Macronutrients and Micronutrients

Plant need water, air, light, a suitable temperature and 16 nutrients to grow.  Plants get carbon, hydrogen and oxygen from air and water.  The other 13 nutrients come from the soil.  Soil nutrients are divided into two groups according to the amounts needed by plants.  

The macronutrients are Nitrogen, Phosphorus, Potassium, Calcium, Magnesium and Sulphur.

The micronutrients, which are needed only in trace amounts, are iron, manganese, boron, zinc, copper, molybendum and chlorine.

These nutrients are essential for plant growth.  Plants will grow normally until they run short of one nutrient.  Then growth is limited by the availability of that nutrient.  Occasionally, two or more nutrients will run short at the same time.  If the nutrients are deficient, or too abundant, then plants will be discolored or deformed.  The deficiency symptoms will indicate which nutrient or nutrients are needed.  However, it is much better to supply additional nutrients before deficiency symptoms appear.  A soil test will tell which nutrients are low before growth is affected.

Macronutrients:

Nitrogen, N : Stimulates leaf and stem growth.  Nitrogen deficiency causes reduced growth and pale-yellowish-green leaves.  The older leaves turn yellowish first since the nitrogen is readily moved from the old leaves to the new growth.  If the soil is cold and wet, nitrogen in the soils is not as available to the plants.  Excess nitrogen may cause potassium deficiency.

Phosphorus, P:  It is important in the germination and growth of seeds, the production of flowers and fruit and the growth of roots.  Phosphorus deficiency causes reduce growth and small leaves that drop early, starting with the oldest leaves.  Leaf color is a dull, bluish green that becomes purplish or bronzed.  Leaf edges often turn scorched brown.  Excess phosphorus may cause potassium deficiency.

Potassium, K: Promotes general vigor, disease resistance and sturdy growth.  Potassium deficiency causes stunted growth, with the leaves positioned close together.  Starting with the older leaves, the leaf tips and edges turn scorched brown and the leaf edges roll up.  Excess potassium may cause calcium and magnesium deficiencies.

Calcium, Ca: It is a major ingredient in cell walls and is important for root growth, especially that of the root tips.  Calcium deficiency causes poorly developed roots with weak tips.  Leaves are distorted, with hooked tips and curled margins.

Magnesium, Mg:  It is a vital for chlorophyll production, and is important in most enzyme reactions. Magnesium deficiency causes different symptoms in different plants, but commonly includes leaf-yellowing, with brilliant tints.  Leaves may suddenly drop off without withering.  Symptoms show first on older leaves.  Excess magnesium may cause calcium deficiency.

Sulfur, S: It is an ingredient in proteins and is necessary for chlorophyll formation.  Sulfur deficiency causes slow growth, with small, round leaves that roll upward and are stiff and brittle.  Leaves drop off and tips buds die.

Micronutrients:

Iron, Fe: It is necessary for chlorophyll formation and for oxygen transfer. Iron deficiency causes leaf-yellowing, while leaf veins stay green.  Younger leaves are affected first.  Excess lime may cause iron deficiency.

Manganese, Mn: It is a catalyst for many enzymes, and is important for chlorophyll formation. Manganese deficiency causes different symptoms in different plants, but commonly causes leaves to turn yellow, while veins stay green.  White or gray specks may appear on leaves.  Older leaves are affected first.  Excess manganese may cause iron deficiency, and may cause symptoms similar to manganese deficiency.

Boron, B:  It is necessary for the movement of sugars, for reproduction and for water intake by cells.  It also tends to keep calcium in a soluble form.  Boron deficiency causes distorted and dead growing tips, hollow stems and deformed fruit.  Leaves are often scorched and curled and are sometimes mottled and discolored.  Young leaves are affected first.  Excess boron may cause scorched leaf edged similar to that caused by potassium or magnesium deficiencies.

Zinc, Zn:  It is necessary for the production of proteins and affects plant size and maturity.  Zinc deficiency causes leaf-yellowing between the veins, usually with purple or dead spots, starting with the older leaves.  Leaves are positioned close together, and are small and deformed.  Fruiting is reduced.  Excess Zinc may cause iron deficiency.

Copper, Cu: It is necessary for the production of proteins and is also important for reproduction.  Copper deficiencies cause bluish-green leaves that may wither or fail to unfold.  Younger leaf tips may be yellow at the edges.  Growing tips may form rosettes.  Excess copper may cause iron deficiency.

Molybdenum, Mo:  It is essential to nitrate enzymes and for the formation of root nodules in beans and peas.  Mo deficiencies cause yellow mottling and dead spots on the leaves.  In some plants, the growing tips are distorted or killed.

Chlorine, Cl:  It may affect carbohydrate metabolism and photosynthesis.  Chlorine deficiencies may cause stubby roots and wilting.  Excess chlorine may cause leaf edges to scorch in a similar way to that caused by potassium deficiency.

(Do not forget to review about feeding your orchids Here!!!!)