a sick potted millettia reticulata shrub wisteria
This wisteria was doing fine, blooming good, then temps got up over 100 F for 2 weeks. The leaves started veining bad, so I put half cup iron plus on it. Leaves kept dropping. The pH is 6. I have 2 other U. S. wisteria in ground (vines). When they vein, I throw a little iron on them and the leaves turn back dark green. I know pH 6 is about right, but are they prone to some kind of soil fungus? Don't have much time down in southern Texas, Zone 9b. Thanks.
Certified GKH Gardening Expert
In that kind of heat, in a pot, the plant may not be able to take up enough water so that it can take up the iron it needs. Increase water to the plant and that should help. Plants can only take their nutrients up in combination with water. Not enough water will mean not enough nutrients. Plants in pots need much more water than plants in the ground as the water can evaporate quickly, especially in high heat.