I came across this neat little list that can probably help a lot of people out. If you like it check my post in the General area...I need some help! Quick Deficiency Guide Nitrogen: Entire plant is light green in color; lower leaves are yellow; growth is stunted.... Phosphorous: Entire plant is bluish-green, often developing a red or purpleish cast; lower leaves may be yellow, drying to a greenish-brown to black color; growth may be stunted... Potassium: Leaves have a papery appearance; dead areas along the edges of leaves; growth is stunted... Magnesium: Lower leaves turn yellow along the tips and margin and between the veins; the lower leaves wilt... Calcium: Young stems and new leaves die... Zinc: Leaf tissue between the veins is lighter in color; yellowed; papery in appearance... Iron: Leaf tissue appears yellow, while the veins remain green... Copper: Leaf edges appear dark green or blue; leaf edges curl upward; young leaves permanently wilt... Sulfur: Young leaves turn pale green, while the older leaves remain green; plant is stunted and spindly... Mananese: Growth is stunted; lower leaves have a checkered pattern of yellow and green... Molybdenum: Leaves are stunted, pale green, and malformed... Boron: Young leaves are scorched at tips and margins...