How to revive False Sunflower?
 

Hi,
I am a novice gardner and beginning to garden with simple, easy to
grow wildflowers and the likes. I planted a couple of young false
sunflowers and a coneflower plant I bought from Home Depot. They are
in direct sunlight in a well drained moist soil. The coneflower is
blooming but looks weak and twiggy with a lot of yellow dry leaves at
the base of the plant. Both the false sunflower plants lost all their
foliage. I simply trimmed them down to a couple of inches above the
ground level. It has been a week now and the bare stems still seem
firmly rooted. Is there any way I can revive these false sunflower
plants? Please help. I love plants, but I am so bad at gardening. I
spent about $300 on yard services and new plants from an "arborist"
and I cannot afford any more this season. Please help.

Cheers,
Sapn