I attended a class today from an Instructor who is a Master Gardener. It is interesting what you can learn. He said that if you plant veggies in black containers, the heat can get as high as 120 degrees. His suggested was to spray paint the black pots a white color before using them. He also spoke about using a fertilizer that should always start with a 10 - for example - 10/10/10 because the Nitrogen is the first 10 and it will release the quickest and therefor a fertilizer starting with a number 10 first, is the best.
Don't know if this is useful or not but here are a few other tips:
To make your own soil for starterseeds, include the following:
1) 2 parts compost
2) 2-4 parts Sphagnum Peat Moss
3) 1 part sand
4) s part Perlite
5) 1 part Vermiculite
Fertilizing annuals such as tomatoes, peppers,corn etc... (every two weeks) only use a water soluble fertilizer and for perennials - (every 4-6 weeks) only use a slow release in conjunction with a water soluble.
You might want to follow this guys link at www.thecitrusguy.blogspot.com/