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Plant Symptoms for Soil Deficiencies: If your plants are growing slowly, look skinny, and have yellowing leaves and stems all over the plant, this might be because of a lack of nitrogen. If the plant's lower leaves are yellow and you observe this symptom moving up to the middle and then the top leaves of the plant, the problem could be a lack of potassium. If, on the other hand, just the top leaves curl up and turn yellow, your soil could be missing essential amounts of calcium.
Why Are My Vegetable Plants Turning Yellow? We all have plants that don't look the way we know they should. This site explains what could be soil deficiencies and if so, how your plant will look so that you can diagnose it. http://www.ehow.com/how-does_5183658_vegetable-plants-turning-yellow_.html
“Even if I knew that tomorrow the world would go to pieces, I would still plant my apple tree.” - Martin Luther
Soil Prep for the Vegetable Garden
Plant Nutrient Deficiency Symptoms - great graphic.
Turn teacups into plant holders. | 51 Insanely Easy Ways To Transform Your Everyday Things
Tomatoes.... Detailed list of mineral deficiencies and what they look like Symptoms of Deficiency in Essential Minerals
Bad soil? No soil? Plant in straw bales instead.
How to Make your Own Vegetable Seed Starting Soil by Mike the Gardener
How to Make your Own Vegetable Seed Starting Soil
Skip the ground and try planting fruits and vegetables in straw bales instead, suggests Joel Karsten, author of “Straw Bale Gardens”
label the end of silverware and bury in soil along side plants
Nutrient Deficiency in Plants