Clematis: Help please, clematis Jackmanii leaves have turned yellow , 1 by sempervirens

sempervirens wrote:
Thanks niobe and Jeanne for your quick response.
The Jackmanni has been in place for 5 years. Last year mid season it started to show signs of yellowing leaves with green veins. I added extra compost as a side dressing with Greensand and sprayed it with a seaweed and fish emulsion. Although it looked better the yellowing was spreading slowly so I used a planrt spike of "Ironite Plus" 12-10-10. The yellowing seemed to stop although some of the lower leaves didn't entirely recover.
This year the vine started out with green leaves that quickly turned yellow, some are solid yellow. So far I only sprayed the leaves with seaweed. The Jackmanii has not bloomed yet.
I added the Lonicera sempervirens 2 years ago.
This corner area along the driveway does suffer when it rains really hard and continuously. The water washes through that corner and puddles on the side walk in front of the fence. I thought the rain might be washing away nutrients.
On the opposite end of this narrow fence garden, about 10 ft. away. is a healthy Etoile violette twined through a Autumn Sunset Rose. Underneath is a beautiful full "Caramel' Heuchera. The Heuchera under the Jackmanii has dwindled in size and vigor.
Here's a photo of the leaves.