Plants require nutrients to grow, like all living things.
For plants meant to grow food, particularly high-yield plants, you need to keep a close eye to be sure they are getting essential plant nutrients to prevent disease and poor crops.
While a balanced fertilizer should help, if your soil was already nutrient deficient or your plant requires a lot of a nutrient, you may see signs of nutritional deficiencies.
This list will help you both identify plant deficiencies and how to fix them naturally. Be sure to have your soil tested, so you know how best to fix the problem.
Also, check any organic amendment or treatment to be sure you understand how to use them. Read the labels carefully.
With calcium deficiency in plants, young leaves will be affected first. They will be distorted (cupped or curled up), small, and yellowish/brown spotted or have dead areas.
Bud development will be inhibited or slowed and root tips can die. Fruits will be small.
Blossom end rot on tomatoes is caused by calcium transport issues within the plant. This can be caused by your soil being too acidic, which is anything below 6.0.
If your pH isn’t the issue, then bone meal can help add more calcium. You can also add eggshells to your compost to help add more calcium naturally.
Your plant will likely be shorter than average for the variety. Leaves will be a pale yellow-green, particularly on older foliage. In tomatoes, you may see a purple coloration on stems and leaves.
You may see symptoms of nitrogen plant nutritional deficiency after it rains since nitrogen is very soluble and may wash out of the soil.
You can help prevent it by mulching with well-rotted garden compost or manure. In the short-term, poultry manure pellets can help.
An organic fertilizer such as bat guano meant for the stage your plant is in, can help.
Magnesium nutrient deficiency is most commonly seen on tomatoes, apples, grapes, roses, and rhododendrons.
You’ll see yellowing between the veins on older leaves or early leaf fall.
An excess of potassium can cause magnesium deficiencies since plants will take up potassium in preference to magnesium.
Epsom salt solution can help, as well as Epsom salts added to the soil.
Your plant will be stunted and a dark green color. You’ll see symptoms on older leaves first, and maturity will be delayed.
This type of plant nutrient deficiency can be caused by the conditions being too cold for the plant to absorb phosphorus.
Phosphorus deficiency is fairly uncommon in crops but may be seen in areas with clay soil or heavy rainfall. Bone meal is a good option to use for replacing phosphorus.
Older leaves will yellow with scattered dark brown or black spots. If the deficiency is severe, your plant will be stunted and have curled yellow leaves.
On lettuce plants, the leaves may appear bronzed, with the symptoms starting on older leaves. You may also see poor flowering or fruiting.
Pick a high potassium fertilizer like the ones left behind from sugar beet processing.
One other way to treat potassium plant deficiency is to bury bananas peels 1 inch below the soil. This method takes longer to fix the issue, but it will help in the long term.
New growth will be yellowed. Your plant will also be stunted. High rainfall and soil with lots of iron can both cause sulfur nutritional deficiencies.
Nitrogen deficiency can look similar in new seedlings, but it will have a red pigment in the veins of young leaves while sulfur deficiencies won’t.
Sulfur absense can be corrected with well-aged or composted manure or garden compost that contains food scraps.
It may also fix itself as temperatures rise since microbial action that makes sulfur available to plants is reduced in cold temperatures.
Plant size is usually smaller and the growing point may die back. Root tips will frequently be discolored and swollen.
Leaves will thicken and become brittle. They may also curl with yellow spotting.
It shows stunted growth on lettuce, brown cracks on celery, and dimples with brown patches underneath in pears.
Giving enough moisture to your plants will prevent boron deficiency. Boron is not absorbed well when moisture levels are low.
You can add compost teas as treatment as well.
Copper is one of the most uncommon types of plant nutrient deficiencies.
However, plants afflicted with it will have young leaves turn a dark green and may see them become twisted or misshapen.
You will likely also see brown, dry spots on the leaves. It tends to be seen most commonly in waterlogged soil or soil with improper ph.
Have your soil tested and try to make sure it is between 4.5 and 7.5. If you have improper drainage, transplanting the plant to better-drained soil or a raised bed may help.
If your soil is copper deficient, there are organic copper fertilizers available. Just follow directions carefully to ensure you don’t add too much.
Leaf veins will stay green, while the area in between will yellow. Iron deficiency is seen first on young leaves and new growth, unlike magnesium deficiency which shows on older leaves first.
In tomatoes, this can be caused by temperatures being too low for nutrient uptake. This condition is more common in alkaline soils or acid-loving plants.
Biomin iron can help. Most iron deficiencies will be seen with manganese shortages. Iron deficiency in soil is rare, so be sure to test to see what the real issue is.
Clay soils for instance need to be amended with organic matter. Too much phosphorus or overly wet or compacted soil can also cause iron deficiencies.
Initial symptoms include interveinal yellowing. Whether this appears on younger or older leaves depends on the plant type.
You may see brown, dry areas that fall off. Like iron deficiencies, manganese deficiency is seen in more alkaline soils or with acid-loving plants.
You can buy treatments meant to add more manganese. Foliar application is the best solution, particularly in heavy soils where manganese is tied up quickly.
Older leaves will have interveinal yellowing, with younger leaves eventually affected as well. Leaf edges may develop cupping or scorching.
It’s most commonly seen on cauliflower or similar brassicas grown in insufficiently alkaline soil.
Making the soil more alkaline will help in the long term since molybdenum is rarely unavailable in the soil since not much is required. You can also apply Brandt or lime to your soil.
The plant will be short, and the length between nodes will be smaller. Leaves will also be smaller in healthy plants.
Leaf edges may be puckered or distorted, and you may see yellowing between the veins. It is most common in citrus trees.
A foliar spray is recommended to fix the issue in the short term. Be sure to add more to the soil if a soil test shows yours is deficient. You can also use Biomin zinc.
Be careful with fertilizers that are high in phosphorus since that decreases the amount of zinc available to your plants.
Oxygen deficiency can be seen in the roots, which turn brown and mushy instead of white and firm.
This is most common in hydroponically grown plants with insufficiently oxygenated nutrient solutions. In soil-growing plants, this is seen in those that are overwatered.
Never water more than the plants and soil can absorb in a few hours. It is very difficult to fix root rot once it sets in, so prevention is the best solution.
14. Carbon Dioxide
Carbon dioxide deficiencies are most commonly seen in plants grown indoors. The plant will be stunted and take up less water.
A fan can help circulate air, and being around your plants can help since you breathe out carbon dioxide.
If you grow a lot of plants indoors, a fan connected outside or a carbon dioxide generator can help.
Nickel is a poorly understood plant nutrient deficiency. Seeds with nickel deficiencies will show poor germination.
Low nickel in leaves may cause leaf burn. Since it is only recently discovered as necessary for plant growth, it isn’t commonly added to fertilizers or tested for.
It can be found as a contaminant in some fertilizers and animal waste. You can apply it as nickel sulfate or chelated nickel, however, it is easy to add too much.
While deficiencies in plants can be frustrating, most can be fixed relatively easily. Have your soil and plants tested, watch your pH, and water appropriately.
Remember to follow directions on organic fertilizers to be sure you’re applying the right amount for your plants.
Asking for advice from your local gardening center can help if you’re unsure about what plant nutrition problems your crops are experiencing.
Just remember to keep up with watching your plants and changing up what you give them as they reach new stages in their growth.