Would like to grow a couple of yucca for showiness as well as for yucca moths. I've seen smallish ones and some that are as big as large shrubs. Thoughts on species/varieties? Needs to be winter hardy.

The first one in the data base is yucca filamentosa, and is said to be good to zone 4a . I don't know whether it is one which attracts the yucca moth.

CarolineScott said: I don't know whether it is one which attracts the yucca moth.

All Yuccas attract Yucca Moths. Both are necessary for each others survival. Yuccas will not produce seed with out the moths and the moths only reproduce on Yucca.

@UrbanWild I'm not sure if different species of moth are attracted to certain Yucca or not, but I would suggest that you research what species of Yucca grow in your area and plant those. Since the species of Yucca native to your area are already attracting the moths in you area then they would be the best choice.

According to the BONAP atlas (http://bonap.net/NAPA/TaxonMap...) Y. flaccida is native to Kentucky. However, my copy of Jones' Flora of Kentucky shows it and [Y. filamentosa] are not natives but regular escapes here.

Actually BONAP shows both Y. flaccida and Y. filamentosa as "adventive", not native but introduced from a nearby state. Even though they are not native to your state, they are growing wild their which means that Yucca Moths are using them are they would not be growing there. The moths may use any Yucca available, but since those two are what grows there (Y. flaccida seems to be the most abundant) they would be my first choice.

Map for Y. flaccida shows most Kentucky counties dark green on the map. In the corresponding color key (http://www.bonap.org/MapKey.ht...), that would be native. Y. filamentosa map shows 108 out of 110 counties in dark green.

That said, I've been in all counties in KY and would be hard-pressed to remember a county in which I have not seen yucca growing either in cultivation or as an escape. Odd, since we have been trying to expand the few plants at my folks' house for 10+ years to no avail. BTW, I've never seen a yucca in bloom in KY which did not have yucca moths.