Iron Chlorosis in Gardens and Landscapes
- Caitlin Youngquist
- Aug 3
- 2 min read
We have seen a striking amount of iron deficiency in garden and landscape plants this year (2026), including lawns. This condition is not uncommon in our alkaline (high pH) soils, but this year has been extreme. This is likely due to the drought and a decline in the soil microbes that help plants uptake iron from the soil - especially micorrhizal fungi and plant growth promoting bacteria.
You can recognize iron deficiency in plants by the distinct interveinal chlorosis on the newer growth. Unlike nitrogen, iron is not mobile in plant tissue. In extreme cases you will see scorching of the leaf edges.
Unlike nitrogen, iron is not mobile in the plant tissue, so you will see yellowing on the newer leaves instead of the older leaves. Zinc and manganese deficiency can look similar, but typically appear first on the older, interior leaves.
Lack of nitrogen can also make leaves pale yellow, but the veins will not stay dark green, and the older leaves will show yellowing first.
What Can We Do?
Short Term:
Treat all plants with a liquid chelated iron product available at most garden centers or online. This is a concentrate that you will add to water or compost extract. Follow the instructions on the package. In extreme cases you can increase the frequency and rate of application a little bit. Be sure to spray early in the morning when the stomata on the leaves are open.
Add liquid fish/kelp for added nutrients and microbial benefits.
Mulch your soil to keep the soil temperature and moisture more consistent, and provide a food source for worms and fungi.
Avoid over or under watering. Both of these can contribute to nutrient uptake issues in plants. Keep soil consistently moist but not saturated.
Long-term:
Add compost and other high-carbon amendments to the soil in the fall (leaves, alfalfa hay or pellets, wool, leaves and grass clippings, manure, etc.).
When planting garden crops or perennials in the spring use a good liquid biological / nutrient product to dip roots and treat the seeds (compost extract, liquid fish and kelp, commercial microbial inoculant).
Water very heavily in the fall to build up the soil moisture going into the winter, and a few times throughout the the winter, especially in dry years.
Treat perennial landscape plants with a good quality commercial micorrhizal inoculant. There are many products on the market, and you will have to do your own due diligence to find one that is of high quality.
Additional Reading
Iron Chlorosis of Woody Plants - Colorado State University Extension
Identifying and Correcting Iron Deficiency in Ornamentals - Oklahoma State University
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