Plant Nutrient Deficiency Symptoms With Pictures

Most Common Plant Nutrient Deficiency Symptoms – N, P, K

Nitrogen (N), Phosphorus (P), and Potassium (K) represent the most common nutrients given to plants as fertilizer. With enough NPK plants grow to maturity, fruit, and provide bountiful harvests. Without them plants are stunted, take longer to fruit, and reduce or eliminate yield. 

NPK is so important that you won’t notice it’s missing at first. Plants will utilize all available NPK from their seeds to grow bright and green. At first.

Over time the older leaves begin to show yellowing or spotting. 

Then you’ll notice stunting. You’ll notice it’s taking much longer for the plants to grow.

At this point it’s not too late for perennials like trees and shrubs. Simply provide what they need and they’ll respond. 

You might have to skip a harvest this year but for the home grower of trees and shrubs you’ll have a better harvest next year.

For annuals that you expect to harvest this year you could have a disaster. Tomatoes may not ripen. Cucumbers never arrive. Your green thumb privileges revoked (or you fear you never had them).

All of this can be prevented by carefully watching your plants and looking for the signs.

Here are the 5 signs of the most common plant nutrient deficiencies with pictures

Not Enough Nitrogen

nitrogen deficiency rose
Image by Beverly Buckley from Pixabay

Older leaves are yellow-green. Plants are stunted. Tomato leaves may have purple spotting underneath. 

Solution? Test your soil. Add NPK fertilizer as needed.

Not Enough Phosphorus

phosphorus deficiency
Image by ABo from Pixabay

Stunted, dark green plants. Plants take longer to mature and fruit. Cold soil can prevent phosphorus absorption. 

Solution? Test your soil. Add NPK fertilizer as needed.

Not Enough Potassium

Potassium Deficiency
Image by Marc Ouye from Flickr

Yellow older leaves with black or brown spots. Browning at the edge of the leaf. Stunting occurs if the deficiency is great enough. 

Solution? Test your soil. Add NPK fertilizer as needed.

Warning – adding too much potassium can cause a magnesium deficiency as plants take up potassium faster than magnesium.

Not Enough Magnesium

Magnesium deficiency
Image by Scot Nelson from Flickr

Yellow between the leaf veins. Solution? Add dolomite limestone or epsom salts as directed. 

Warning – See note above about adding too much potassium.

Not Enough Manganese or Iron

Iron deficiency
Image by Scot Nelson from Flickr

Look for yellowing between leaf veins for acid loving plants (citrus, blueberries) that were planted in alkaline soils or soils that are alkaline (high pH) in general. 

Solution? Check the pH of your soil and lower it till it’s between 5.5 and 7.

What Happens If A Plant Doesn’t Get Enough Nutrients?

The most common symptoms when a plant doesn’t get enough nutrients are:

  • Yellowing of older leaves
  • Stunted growth
  • Longer to maturity or fruiting
  • Yellowing in between veins
  • Browning on edge of leaves
  • Purple or brown spots

Should You Cut Yellow Leaves Off Of Plants?

Yellow leaves should be allowed to turn fully brown before cutting or pruning. Plants are pulling as many nutrients as they can from yellow, dying leaves. Cutting them too early will prevent the plant from getting the nutrients it needs.