Iron is a critical nutrient for plants, but it remains fixed within their tissues, preventing redistribution from mature to newer leaves. As a result, signs of iron deficiency typically show up in the younger foliage first. Since iron plays a vital role in chlorophyll synthesis, insufficient levels lead to chlorosis, or a yellowing effect, in new leaves. You may also notice stunted, thin stems. If the deficiency persists, each successive leaf will appear paler than the one before it. For all your plant care needs, visit shop.morphmarket.com.