.......The only useful guideline is to know your plants and the conditions they grow in in nature.
Hmmm - OK, but the guidelines are not always too easy to interpret. Take
Crocus robertianus - a plant which I have found difficult. Mathew (p66) describes it as growing “in semi-shade......between and at the edges of deciduous.......scrub. The soil is a sandstone-shale, rather moist from the autumn to late spring and then becoming rather dry but never hot and sunbaked.”
I took this to mean a dry but relatively cool summer in the shade. Following this regime, I lost many plants over the years (not "fun" at all). More recently I have had more success by keeping them outside all the time so they receive whatever the local weather delivers.
How would you interpret Mathew’s description of the natural conditions?