Why do you need to fertilize, really? Plants grow in a wild and no one fertilizes them; garden centers are full of nice looking plants, what else do you need?
And here is the trick...
Have you noticed that once you move a plant from a pot into the ground, it starts growing bigger, faster and better? What was wrong with a pot?
Do you remember that nice looking plant you purchased from a greenhouse that became not-so-nice looking just in a couple months?
You watered it, yes. But it became leggy, dropped all the flowers, got infested by bugs, and leaves are not as green any more... What happened?
Your verdict was, you just had a brown thumb and no luck with plants.
This is not why! Now we will explain what happened, and how to make it right. Easy - as a 1-2-3-4-5.
When a plant grows in open ground, it takes essential elements from the soil. Such elements as N, P, K, Ca, Si come from soil solids in a form of various salts. Trace elements (micro-elements) such as Fe, Mg, Mn, Cu, S, Zn are also available from soil compounds. Organic humic acids, so necessary for plant growth, are also there as a result of humus decay process. Special bacterias that turn organic matter into plant food, as well as worms and other soil fauna, help to create ideal substance that has everything necessary for a plant growth. The more the root system grows and spreads, the more nutrients it can reach and consume, so the plant starts growing faster and faster.
Container grown plants have to use what they have, with no choice. Their roots may try to "escape" throught the holes in the bottom of a pot in hope to reach wider horizons of nutrients, but have no luck, unless a stong taproot digs into the ground and gets its free access to more food! Otherwise, plant's roots are doomed to sit in a SOILLESS MIX which is originally FOODLESS.
Soilless mix = bark + peat + perlite, this is a general formula. Unless you provide PLANT FOOD, your plant gets by without a meal, and very soon becomes skinny, pale, bugsy, and sick. Just like every live creature.
Soilles mix is a great media (and the best media for potted plants). However, since it is lacking those elements available in soil, it is a kind of hydroponics. It is well known that in hydroponics, all plant food must be provided with nutrients through constant fertilizing program.
How to grow healthy, fast growing, and good looking plants?
Can you get a Magic Wand for profuse flowering, green leaves, and large fruit?
All you need is just a Green Thumb that fills all the gaps!
Considering you already know that all plants need LIGHT and WATER, we can have a FOOD talk. These are important components of the Plant Nutrition System:
1. Growing Media is a start. It will hold the plant, the water, and the plant food. It will have necessary bacteria to help the plant digestion.
2. Macro-nutrients NPK. These are major essential elements.
3. Calcium. A necessarry support that is present in soil, but lacking in potting mix.
4. Micro-nutrients. To provide trace element support and correct possible element difficeincies.
5. Bio-stumilants. To provide immunne system support, vitamins, and protect plant from environment.
Sunshine-Epi, Sunshine HumiHum, Suchine-Si-Power.
See also Sunshine Combo Boosters guide (pdf download)