Have you noticed some of the leaves of your plants turning yellow?
Yellow leaves are usually a sign of either a lack of nitrogen OR iron. So, how can you which one your plant is deficient in? Well, it is really quite easy.
Monday, we talked about nitrogen deficiency, which causes older leaves to yellow and newer leaves to stay green. However, when it comes to iron deficiency it is the opposite – younger leaves turn yellow first.
The other characteristic of iron deficient plants is that although the younger leaves turn yellow, their veins remain green.
Iron is needed for plants to function. Without it, they will not grow.
What is interesting about iron is that there is usually plenty of it in the soil. BUT, certain factors can affect it being available for plants to absorb. If your soil is wet, has a high pH (alkaline soil), and/or clay soils are all factors that can lead to iron from becoming unavailable for plants.
So, how do you correct iron deficiency in your plants?
1. A fast-acting solution is to apply an iron chelate fertilizer to your plant. For the best results, use an iron chelate product that can be sprayed on the foliage. You can also apply iron chelate to the soil around your plants. Iron chelate can be reapplied as needed. *As with all fertilizers, follow instructions on the package CAREFULLY. You don’t want to apply too much iron. (Iron chelate can stain concrete, so be careful when using).
2. If you have clay soil, or your soil is compacted or overly wet – then working a mixture of compost and peat moss into the soil around your plants will help to provide a long term solution to iron deficiency. Adding organic matter will help to improve the texture of your soil, helping it to drain better. Compost and peat moss will also help to lower the pH of your soil, which will help the iron in your soil to become available to your plants.
3. Have your soil tested to see what the pH of your soil is. You can purchase a home soil testing kit at your local garden center – it’s easy to do. IF your soil pH is over 7.0, that means that it’s alkaline and taking steps to acidify your soil should be taken to help your iron deficient plants.
4. Adding ammonium sulfate or elemental sulfur will also help to acidify your soil (lower the pH), but the effect won’t last forever. They will have to be reapplied periodically.
Iron deficiency is best treated by preventing it from occurring in the first place. If your soil pH is over 7.0, clay-like OR often wet – then incorporate compost and peat moss before planting.
So, if the new leaves on your plants are looking yellow and have green veins – DON’T WORRY! You can help them by following one or more of these tips
**Learn more about testing the pH of your soil and determining your soil’s texture in this great article.