Question

Photo of Leaf   I have a large verigated arrowhead plant that has started getting brown spots on the leaves with others turning yellow. I have been trimming off the leaves that are yellow, but would like to know what is causing the brown spots on the leaves. The spots tend to be large. In addition, new leaves are sprouting with brown spots on them as well. Thank you for any assistance you can provide. This is a special plant from my mother-in-laws funeral so would like to salvage it if possible.

Answer
Peggy,

It is either because you are keeping it too wet or too dry. You did not tell me how often you are watering or anything about how you are caring for the plant. It could also be sunburn if it is outdoors in full sun.

All plants should be in a pot that has a drain hole and a drain tray under it. When you water a plant you should give it enough water so all the soil in the pot is moist and a little goes in the drain tray under the pot. An hour after watering you should empty the water in the drain tray. If you can't pick it up to do that you should use a turkey baster to suction it out. That way your plants are not sitting in a swamp. Sitting in water will cause root rot which causes yellow spotting of the leaves. Even if it is not sitting in water if you come back in seven days and water it again because it is time even though it is not dry that also is like being in a constant swamp. Roots need to have time to breath in carbon dioxide through the soil in between watering for a couple of days. If the soil is constantly wet they can't do that. For the roots to use up all the water in the soil before you come back with more water you needs to drain away the excess water right after you water, therefore a pot with a drain hole will mean less wet soil and the plant will be dry in a week. If it is not at first wait a few more days before watering. Gradually the plant will grow more roots and use water up faster. As it grows more roots it will grow better and support more top  growth and be a much healthier plant. Try to make sure it gets 2-3 days of appearing to be dry between watering. It will still have some moisture down in the bottom of the pot.

If it is already in a pot with a drain hole and it dries out between watering it could have a fungal problem and you can spray it lightly but thoroughly every 3 days for a month with Lysol spray and that will kill bacterial or fungal infections but it really looks like a moisture problem and better drainage and drying out between waterings will cure that. Good luck!

Darlene