Robust garden growth and abundant harvests depend on your plants getting the nutrients they need. When plants lack sufficient supplies of essential nutrients, appearance and productivity suffer. Leaves usually provide the first visible clues. By understanding nutrient deficiencies and their signs, you can correct and prevent nutrient problems and keep your garden performing at its peak.
Nitrogen deficiencies turn entire leaves yellow, starting with the oldest leaves.
Plants require several essential nutrients to survive. Carbon, hydrogen and oxygen come from air, but plants rely mostly on soil or added nutrients for the rest. Nitrogen, phosphorus and potassium — noted on fertilizer labels by the N-P-K ratio — are called primary macronutrients. Plants need these three in larger quantities than any other essentials.
Secondary macronutrients include calcium, magnesium and sulfur. Equally essential micronutrients, including iron and zinc, are required in smaller amounts.
Nutrient deficiencies occur when something prevents the plant from getting sufficient amounts of one or more nutrients to support photosynthesis and healthy green foliage. Nutrient needs shift with phases of plant growth.
Deficiencies can happen when a nutrient is missing or lacking in soil, growing media or nutrient solutions. But they can also occur when nutrients are present and plentiful, but plants can't access them as they normally would.
Poor growing conditions, including improper watering, poor drainage and root damage, can inhibit a plant's ability to take up nutrients. But pH imbalances in soil can prevent normal nutrient uptake.
When pH strays outside optimal zones for different plants, some nutrients become tied up and unavailable. For example, iron is most available to plants in acidic soils. Overly alkaline soil can block normal iron uptake, even though iron is present in the soil.
Unnatural purplish leaf color on older leaves signals phosphorus deficiency.
Nutrients vary in how they move through plants differently, just as they do in soil. Nitrogen, for example, moves through soil easily and leaches away with heavy irrigation or rain. Nitrogen is also highly mobile in plant tissues. When plants have sufficient nitrogen, it moves throughout the plant, from the oldest foliage to the newest branch tips and tops.
When plants have insufficient nitrogen, the nutrient still moves to those new leaves. As a result, older leaves show signs of nitrogen deficiency. With less mobile nutrients, such as calcium, the opposite happens. The insufficient nutrient satisfies older leaves, but can't supply sufficient amounts to new growth. So, youngest leaves display signs of nutrient deficiency first.
Identifying a nutrient deficiency in your plant begins by looking where it occurs: oldest leaves or newest growth. Once that's established, the most common plant nutrient deficiencies offer these clues:1,2
Scorched edges and speckles on older leaves indicate potassium deficiency.
Oldest leaves affected first:
- Nitrogen (N) – Entire leaves show general yellowing, starting in older leaves and progressing through the plant.
- Phosphorus (P) – Older leaves take on an unnaturally dark green or reddish-purple coloration. Leaf tips brown and die.
- Potassium (K) – Leaf margins on older leaves turn bright yellow, then look scorched. Brown speckles may cover leaves.
- Magnesium (Mg) – Older leaves develop yellow patches between leaf veins. Veins stay green as chlorosis expands.
- Molybdenum (Mo) – Entire plant often turns pale green, with oldest leaves turning yellow. Leaves affected between oldest and youngest growth.
Magnesium deficiencies leave older foliage with green veins and yellow margins.
Youngest leaves affected first:
- Calcium (Ca) – Younger leaves turn light green or yellow between veins, new tips may look brown or black, fruiting vegetables may rot at the blossom end.
- Sulfur (S) – General, uniform yellowing of entire leaf starts with young leaves.
- Iron (Fe) – Youngest leaves turn yellow between leaf veins, severe cases bleach entire leaves creamy white.
- Boron (B) – Younger leaves develop yellow edges. Terminal buds and leaf edges die.
- Copper (Cu), manganese (Mn) and zinc (Zn) deficiencies cause yellowing between leaf veins on younger leaves.
When nutrient deficiencies go unchecked, symptoms spread. Expect poor plant vigor, stunted growth, reduced lateral branching, weak flower and fruit development, poor root growth, terminal bud death and disappointing harvests.
Calcium deficiency causes yellowing between young leaf veins and blossom end rot in some fruiting vegetables.
Keeping your garden at the peak of productivity and performance starts with giving your plants proper care and a solid nutritional foundation. Trusted, natural-based plant foods such as Earth Juice Grow 2-1-0 original formula and Earth Juice Bloom 0-3-2 original formula provide essential primary nutrients for robust stem and leaf growth, and rich flower development.
If you suspect a nutrient deficiency but aren't certain, check with your local county extension office. They can provide information and assistance with economical laboratory soil testing and plant tissue testing to confirm nutrient deficiencies and their causes. Then you can take action to restore nutrient balance to your plants.
Iron deficiency starts in young leaves as chlorosis between leaf veins.
Deficiencies of micronutrients such as zinc cause yellowing between veins on young leaves.
With Earth Juice Meta-K 0-0-5 potassium plant food, you can correct potassium deficiencies and enhance plant resilience against common stresses, including cold and drought. Earth Juice Elements Cal-N-Mag Plant Food 3-0-0 helps prevent or treat calcium and magnesium deficiencies, plus it delivers essential nitrogen.
And with Earth Juice Microblast 0.4-0-1.3, you can prevent and correct micronutrient deficiencies with a blast of nutrients, including nitrogen, potassium, magnesium, boron, cooper, iron, manganese, molybdenum and zinc.
With dependable, high-quality Earth Juice products, you can correct and prevent nutrient deficiencies and enjoy beautiful, productive plants and the harvests you desire. Gardeners and growers have been trusting Earth Juice to give fruits and vegetables the best nutrients for 30 years. Let us help you take your garden to the next level.
Always read product labels thoroughly and follow instructions, including dilution rates and recommended feeding frequency for your plant phase and feeding method.
Earth Juice, Elements and Microblast are trademarks of Hydro-Organics Wholesale, Inc.
1. M. Nathan, "Diagnosing Nutrient Deficiencies," University of Missouri Integrated Pest Management.
2. S. Hosier and L Bradley, "Guide to Symptoms of Plant Nutrient Deficiencies," The University of Arizona Cooperative Extension.