Where to Buy Organic Fertilizers
The place to get the best value is New Earth Garden Center in Louisville. You can buy 50 pound bags of nutrients and they will ship them to you, or of course you can drive to Louisville and pick them up. With the cost of gas right now I doubt you will save much driving.
If you are on a limited budget and want just enough organic nutrients for this year then I would go to Lowes. This is the first year I have seen Lowes with a decent selection of organic nutrients. You could also try Fayette Seed but I think they are usually high priced and I have been disappointed in their supply of organic products.
What do those numbers on the bags mean?
First of all not all organic fertilizers are created equal. Ten pounds of a bag with numbers like 3-3-2 is less than a third of the value of the same quantity of a bag with numbers like 10-10-10. The numbers are the percentage of nutrients in the contents of the bag. The first number is the percentage of nitrogen in the bag, the second number is the percentage of phosphorous and the third number is the percentage of potassium.
How to Use Organic Fertilizers
For most home gardeners just buying a bag of fertilizer with all the nutrients mixed together works fine. I like to buy separate bags of nitrogen, phosphorous and potassium. Different plants produce better with certain nutrients. If you want lots of blossoms then you need more phosphorus. If you want a strong thick plant then you need more potassium. If you want lots of leafy growth then you need nitrogen. So when I plant tomatoes I like to use twice as much phosphorous and potassium as I do nitrogen. When I plant lettuce I want lots of nitrogen and potassium and very little phosphorous. That gives me great thick leaves.
Just a couple of other things to mention.
You can save on fertilizer and help control weeds by applying the fertilizer only to the area where the roots will grow. So when planting tomatoes you want to spread it at lease in a two foot diameter. However when planting lettuce use a much smaller diameter. I usually use about a handful for three different plants. Organics are very forgiving but you really do not want to be wasteful.