PLANT NUTRIENT DEFICIENCIES
source: Farmer's Almanac
Getting your soil tested can help you identify causes and determine the best course of action. The information below is general and can help narrow the treatment options.
Having the right soil pH is key to growing a healthy garden, but it’s a factor that’s often overlooked in favor of nutrient levels and soil consistency. While these are also crucial things to consider, the pH of the soil plays a major role in how well your plants can absorb the nutrients you provide them, so it’s important to get it right!
The pH is important because it influences the availability of essential nutrients. Most horticultural crops will grow satisfactorily in soils having a pH between 6 (slightly acid) and 7.5 (slightly alkaline)
Have you noticed purplish leaves? What about yellow leaves on the lower parts of your plants? These are all signs of common plant nutrient deficiencies. Luckily, your plants are telling you what is wrong with them and their problems are easily identifiable. Here are a few common deficiencies and how to identify them.
YELLOW LOWER LEAVES
Symptoms: Lower leaves turn yellow, shrivel, and may eventually fall off. Plants, especially big ones, normally loose leaves off the bottom as they approach the end of the flowering cycle, but yellowing that moves steadily up the layers of leaves during the vegetative stage indicates a problem. Younger plants are stunted.
Cause: Nitrogen deficiency
VERY DARK NEW LEAVES
Symptoms: New leaves are very dark green. The leaves begin to curl downward and their edges become very dry, looking a little like they’ve been burnt.
Cause: Nitrogen toxicity
PURPLISH LEAVES AND STEMS
Symptoms: Stems and leaf veins have a purplish tint. (Plants with naturally purple stems and leaves have a consistent color rather than a changing color from the base to the top.) Plants’ growth is stunted, and they may loose leaves.
Cause: Phosphorus deficiency
YELLOW OR DEAD LEAF TIPS AND EDGES
Symptoms: The tips and edges of newly matured leaves have yellow or dead areas. Stems and branches are weak and break easily. Older leaves may appear reddish and curl upward.
Cause: Potassium deficiency
Symptoms: New top leaves appear mottled, misshapen, or stunted.
Cause: Calcium deficiency
YELLOW OLDER LEAVES
Symptoms: The older leaves (lowest on the stem) turn yellow or bright green, starting at their edges, and may even become white while veins remain dark green. The leaves begin to curl upward and eventually drop off.
Cause: Magnesium deficiency
BROWN, MUSHY ROOTS
Symptoms: Plants’ roots are brown and mushy rather than white and firm. Leaves droop and are pale green to yellow.
Cause: Oxygen deficiency
Cures: When plants’ roots are immersed in stagnant water, they become oxygen deprived and develop root rot.
BANDS OF YELLOW ON LEAVES
Symptoms: Younger top leaves have yellow between the veins, creating a banded appearance, and they begin to grow closely together in bunches. They may also be gnarled or twisted rather than their normal shape. If the plant is in its flowering stage, the buds may die off.
Cause: Zinc deficiency