Posted by Newt on June 20, 2003 at 18:40:15:
In Reply to: Re: Rose plant - No buds posted by Ashley on June 20, 2003 at 17:53:10:
: : Hope this is helpful,
"The easiest thing to remember is that all plants need all three in the right proportions.
N - Proteins are made of chains of amino acids. All amino acids have at least one nitrogen (N) atom. Hence, to make proteins, plants need nitrogen. Most plants take up nitrogen in inorganic* form as nitrate (NO3) or ammonium (NH4). They make their amino acids "from scratch." Animals can't make their amino acids from inorganic molecules; they have to eat plants or other animals and use the amino acids and proteins in their food.
P - (Phosphorus). All organisms use phosphorus to construct the sugar-phosphate backbones of DNA and RNA. They also need P to make ATP, the molecule that all living cells use as the immediate energy source in reactions. Vertebrate bone is made of calcium phosphate, which is why bone is such a good source of P. Plants take up phosphate in inorganic form as phosphate (PO4).
K- (Potassium) - many uses, but especially important in opening and closing stomates, which control rate of water loss in the leaves.
If you add a lot of nitrogen relatively to P, you will get a lot of green growth, which is why high N:P fertilizers are often applied to grass. A low N:P ratio induces many plants to produce more flowers and fruit than green growth.
Personally, I think that most perennial plants are healthier in the long term if you give a fertilizer that doesn't have extremely high N or P.
" "Inorganic" molecules are molecules without carbon. "Organic" chemicals are carbon compounds. Living organisms are mostly collections of carbon compounds in a water solutions. Decomposition breaks organic compounds to inorganic forms, which are than taken up by plants. Inorganic fertilizers (e.g., Miracle Gro) supply nutrients in inorganic forms that the plants can take up immediately. "Organic" fertilizers apply organic compounds, such as dead leaves. The material is broken down by bacteria and fungus and the plants take up the nutrients as they are converted to inorganic form over time."
"A simplified summary:
N, nitrogen promotes new growth.
P, phosphorous promotes maturity (flowers, fruit, seed) and anchoring roots.
K, potassium, promotes feeder roots and acts as a traffic cop for nitrogen and phosphorous."
Hope this helps,