• Nitrogen – Entire plant is light green in color; lower leaves are yellow; growth is stunted.  This is one of the more common deficiencies.

• Phosphorus – Entire plant is bluish-green, often developing a red or purplish cast; lower leaves may be yellow, drying to a greenish-brown to black color; growth may be stunted. This is the second most common deficiency.

• Potassium – Important to enzymes critical to photosynthesis. Leaves have a papery appearance; dead areas along the edges of the leaves; growth is stunted.

• Magnesium – Lower leaves turn yellow along the tips and margin and between the veins; the lower leaves wilt. Fairly uncommon, however excess can lead to potassium deficiency.

• Calcium – Young stems and new leaves die. Excess calcium may lead to boron or magnesium deficiencies.

• 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 – Y oung leaves turn pale green, while the older leaves remain green; plant is stunted and spindly. Fairly uncommon.

• Manganese – 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

Check back next time to learn more about hydroponic vegetable gardening.