|What would cause the leaves on our 2 potted Evergreen Wisterias to yellow and fall off?|
|Evergreen wisteria is not from the genus Wisteria; it is actually Millettia reticulata. This evergreen vine likes full sun, consistently moist but not too wet soil and is cold hardy to USDA zone 7 (0 to 10 F). Yellow leaves can be caused by many things and without more details it's hard to pinpoint, but here are some reasons for yellowing: lack of nitrogen, insufficient light, water-logged soil (plant roots need oxygen to thrive), dry soil, or iron deficiency. If the older bottom leaves are yellow, but new growth is green, it's usually a lack of nitrogen. If new leaves are yellow, with green veins, it's usually a lack of iron. (Lack of nitrogen is a more common problem than lack of iron.) Finally, transplant shock or a sudden change in conditions (from the nursery to your landscape, or temperatures that fluctuate from warm to cold to warm again as weather changes) can contribute. Try to isolate each of these possibilities one at a time to determine the problem. Good luck!