I purchased two tropical hibiscus from Hidden Valley Hibiscus last spring. They grew beautifully last summer and flowered nicely. I wintered them over at work... A retail greenhouse... The temperature hovered in the 40's to lower 50's. They lost most of their leaves, but the stems are still green and flexible. However, they are being very slow to come back into growth. They have a lot of green leaf nodes along the stems, but refuse to actually leaf out. I tried the "Wake Up Spray" from HVH... But so far doesn't seem to be doing much. They are still at the greenhouse, and the temperatures during the day are now in the upper 70's to mid 80's... Lots of sun. Water and fertilize regularly. But yet they just sit there. Any ideas to get them to kick into growth??