|I have recently planted plumbago plants along the west side of my house. They have been growing ok for 3 months or so but some of them are starting to look dried out and yellowish. I'm not sure if they are getting too much water or not eough water. It seems like after it rains there is some standing water in the bed and i'm not sure how to prevent this.|
Both too much and not enough water can be stressful to that plant. However based on the symptoms you described I suspect the problem is too much water, that is, soggy soil conditions. You can try to divert water from that area or put in an underground drainage pipe (French drain) to remove excess water to a lower elevation on the property. If gutter downspouts are part of the problem, try running that water to another area. Keep the soil moist to slightly dry and they should do fine.
Hope this helps.