Yellowing Leaves on Dahlias

[debrac69]

Joey bought me a big 16" pot containing 3 dahlias in it for Mother's Day. They looked great for about a month, but have been steadily declining since then. The 2 most obvious things are yellowing leaves that don't turn brown or drop off, and lack of flower buds. I know they are planted in excellent potting soil with long feed fertilizer so they should be getting enough nutrients. They are also in the line of the sprinklers so they get regular water and don't dry out between. They get at least 6 hours of morning sun if not more.

Anyone have any ideas on what could be going on? None of the 3 plants are doing well though they aren't doing well the exact same way. I mean that none of them have the same degree of yellowing leaves, one put out a couple of small flowers recently but I haven't seen the others even put out buds.

I'm stumped.

I was hoping the tubers could just stay in the pot all season, then they might actually have a chance of being successfully overwintered!

[Danaus29]

Just a guess but they are either overcrowded or trying to go dormant. Can you gently knock the dirt and plants out of the pot and check the bottom of the root ball? If the roots are thick and twisted like a mat around the bottom they will need to be separated and repotted.

[crabgrass]

check for spider mites