This list created and tabulated by Hank Zumach from votes on email robins. These are some plants that people might find difficult to grow.

I wanted to mention that half of these plants I have no trouble growing in northeast Iowa, ones like Great Expectations(slow grower), Super Nova(which grows very fast here), Patriot grows fine for the first few years anyway, and some of the others listed.

1. Lunar Eclipse 10 votes
2. Brim Cup 8
3. Fire & Ice 7
4. Cherry Berry 7
5. Great Expectations 6
6. White Christmas 6
7. Color Glory 6
8. Flame Stitch 5
9. Super Nova 5
10. Knockout 4
11. Patriot 4
12. Tattoo 4
13. Frances Williams 4
14. Sea Thunder 4
15. White Centered Varieties by general acclimation.