beckygardener said:Maurice - Very good information!
Thank you.
Now my question .... do you know if more daylilies have been hybridized in the south over the years to create more heat tolerant cultivars?
I suspect that has been the case, but I have never done an analysis. A proper analysis would compare, over time, the number of daylilies registered by hybridizers identified to location. However, there is a simple check. That is, hybridizers move north less than move south. Daylily World moved from Florida to Kentucky but at least three hybridizers moved from the north to Florida in the same period that I know of - Stamile, Trimmer & Reilly. Another simple check would be to look at the ratio of registered dormants to registered evergreen and semi-evergreen by year going back to the 1940s. That assumes that at least in the past, more dormants were registered in the north than in the south. There is reason to believe that as in the 1940s southern daylily growers emphasized that they were more interested in growing evergreens and encouraging evergreens to be hybridized so that they could have green in their gardens during the winter.
Does regular (sometimes daily) watering help with heat stress, especially during summer? Or is it more about the actual daily temps?
That would need to be checked very carefully if over-watering can cause problems. Basically high temperatures cause more evaporation of water from the soil and plants. Plants need water to grow and when it evaporates it will also act to cool them. Water is lost from sand more quickly than from some other soil types, etc. Plants that are not growing need less water than when they are growing and have leaves, etc. If your plants are doing well overall I would think carefully before changing your watering.
I am also wondering if a shade cloth over raised beds might help reduce heat stress?
Definitely, I would think that is why some hybridizers use shade cloth - to reduce the effect of heat stress on fertility.
