The lack of iron usually comes as a result of squash planting leeching nutrients out of the soil. And in turn, this deficiency leads to a reduction in chlorophyll making. You can resolve this by adding iron chelates to the ground and also sticking to the recommended watering routines for the plant.

An iron deficiency (chlorosis) should be suspected if the leaf veins of the squash plants are green but area between the veins is yellow. A lack of iron availability, not deficiency, is a more accurate description of the problem. Here are natural methods of correcting the availability of iron in soil: Lower soil pH.

Iron deficiency is a serious condition for garden plants like Squash which need it in excess to produce chlorophyll. Without an adequate supply of iron, Squash plants will produce bright yellow leaves that may look suspicious. Iron Deficiency will ultimately reduce plant vigor and affect fruit production.