I've had this bookmarked for ages!! So handy!! Love it!! http://www.michaelkevinsmith.com/nep...ure-Chart.html
Not sure if this was discussed, but I was told burbidgeae is definitely highland and not intermediate. I was also told that altitude doesn't necessarily classify them as ULL/LL or UHL/HL, which I completely agree with. While it may be the biggest factor, each species is its own and may be able to cope with different temperatures than its location. I have an ultra lowland-lowland hybrid in my greenhouse with nights in the 50s and its growing like a weed and putting pitches out like a boss. Insignis x merrilliana.