Fertilizer: What kind is best?

All fertilizer labels have three bold numbers. The first number is the amount of nitrogen (N), the second number is the amount of phosphate (P₂O₅) and the third number is the amount of potash (K₂O). These three numbers represent the primary nutrients (nitrogen(N) - phosphorus(P) - potassium(K)
Ok.  So now what?
. These numbers represent the percentage (by weight) of the three major nutrients required for healthy plant growth, always in the same order: nitrogen-phosphorus-potassium (N-P-K). Each of these nutrients affects plant growth differently, and the formulation you select should depend on your specific gardening needs.

The First number on the label is Nitrogen. 
A good way to remember this and what it's for, is "what's the first thing you see on your plant?  Leaves.  Nitrogen will help the plant produce  chlorophyll, which makes the leaves a darker green color.  If you want a nice, fast growing healthy lawn with deep green leaves, get a fertilizer with a high Nitrogen number.  For example, 36-0-6.  You want to keep your healthy lawn growing more green leaves.  (never put lawn food on your garden or house plants if the Nitrogen number is higher than 20)
So... If you want more leaves, use higher Nitrogen. 

Next Number, please. 
Phosphate is always the middle number.  Always. Phosphorous aids in root development and increases flowering ability and bloom size. The fertilizer industry smartly markets high phosphorus fertilizer as “Bloom Booster.” High-phosphorous fertilizer should be used when plants are being established in your garden – when sowing a new lawn or planting a new tree.  It represents what the plant will produce.  Like Vegetables.  Flowers...and of course, what better way to get these things than good roots development?  Nice strong roots will ensure that your plant can support the healthy leaves, stems and blooms it needs.  (so are you asking yourself "why did the grass fertilizer they mentioned above in the Nitrogen section contain ZERO phosphorus?"  Great question.  Because grass is grown for it's leaves, with shallow roots.  You don't want it to go to seed, so you don't want a lot of phosphorus.  IF, however, you have poor, yellowing grass or you are having trouble with grubs (fertilizer is not an insecticide, just a cure for the damage left behind) etc.- put some higher phosphate fertilizer on your lawn. )

Last but not least.....
Potassium is healthy for everyone, including plants.  Potassium has many functions: It guards the plant against diseases and aids in drought protection and cold tolerance. It also serves a role in improving root development and helps in the process of photosynthesis. You might consider using a high-potassium fertilizer at the start of winter and summer to protect crops from temperature extremes or when insects and disease have caused damage to your plants. It also works right along with the nitrogen to help toughen the roots and foliage, which enhances your lawn’s ability to resist drought, wear and tear, plus diseases. Aids in helping the fruits to ripen. 

Fertilizer companies will add additional ingredients to make up the rest of the 100 percent in the analysis formula.  Once you find a perfect match for you and your plants, you both will be happy and enjoy the years to come. 

Acid Fertilizer

Azaleas, Roses, Rhododendrons, Blueberry, Hibiscus, Gardenias, Junipers and Evergreens are a few examples of plants that need acidic fertilizer.  Hollytone is one standby for acid loving plants that's been around for years- made mostly of chicken manure which is high in acidity.  but far less messy.   and other 

 "Eggshells are almost 100% calcium carbonate, one of the main ingredients in agricultural lime; vinegar has acetic acid & coffee not only lowers your soil pH ,it also enriches it with nitrogen,magnesium and potassium.
too much use of fertilizer can make soil too acidic so thee fertilizers should be used in a limit.

EPSOM SALT FERTILIZER
COFFEE GROUND FERTILIZER
EGG SHELL FERTILIZER
VINEGAR FERTILIZER
FISH TANK FERTILIZER

are some of the accidic fertilizers wich can be made in home with less cost for plants."  I found this part on the web. 

So that's about it...oh, except for Organics and whether to use water soluble granulated, liquid, time release or plant spikes.
Here goes: this is from Wikipedia:
 Organic fertilizers are fertilizers derived from animal matter, human excreta or vegetable matter. (e.g. compost, manure).^[1]  Naturally occurring organic fertilizers include animal wastes from meat processing, peat, manure, slurry, and guano.

Eewwwww.  That second one was a surprise.  Well not really.  Back in the early 80's I found this fertilizer called Milorganite. Made from the sewers of Milwaukee.  I think they still make it today. 
In any case, most fertilizers are  extracted from minerals (e.g., phosphate rock) or produced industrially (e.g., ammonia).
Mostly a matter of preference, although some delicate plants enjoy organic over strong industrially made fertilizers.  If you have a concern about your plant and what food to give it (African Violet, Orchid, Gloxinia etc.) then it's best to research prior to a new feeding.  When in doubt..check it out!
This also applies to what kind of application you wish to use.  Some plants fair better when using a slow or time release plant food.  Osmocote is a good one.  Some plants need food faster if they are looking a little pale- water soluble will get to the roots faster.  Sort of depends on what you need or how ambitious you are.  If you don't remember to feed them during the summer, then a granular is best I suppose.  Espoma, Happy Frog, Miracle gro- all good. 

We recommend feeding your plants and flowers regularly- and that depends on what method you choose.  Here are some exceptions to that rule:
NEVER FEED a seed. This means seed starting soil with plant food in it.
NEVER FEED a wilted plant.  Water it first and wait until fully hydrated- usually a few hours to a day.
NEVER FEED a sick plant - if the roots are overwatered, rotting or has signs of root maggots.  Clean up the root issue first, remove the rotted or infected roots carefully, try getting the soil to dry slowly, when new roots start to emerge, it's safe to feed.  But just a half strength dose. 
NEVER OVER FEED:  if one tablespoon per gallon is good, then 2 tablespoons per gallon would be GREAT, right? No.  Too much concentration of food at one time is not good.  It will burn your roots. 

More questions about food?  Drop us a line and we'll direct your question to one of our specialized growers. 
Happy Gardening!