Why are flower buds falling off wife's Hibiscus flower?

[gary350]

Buds keep falling off of all 6 plants. Rain every day. Temp in 60s & 70s. 10 gallon pots, 75% potting soil + 25% garden soil. Small amount of NPK.

 

[oneeye]

Oh those are pretty hibiscus plants friend. Hibiscus needs to be kept moist but not soggy. Looks like a "bud drop" and the reason it happens is because of environmental issues. Water management problem and it looks like too much. When it rains put the plants in or under the shed or awning and don't let the rain hit the pots. Also when it gets hot the plants can cook on the concrete. I recommend you put a small temperature gauge on one plant to monitor the temps for all of them. When plant drop their flower its mad about something.