Welcome to my world - LOL! I've learned (the hard way) to REALLY research each and every cultivar I 'need'. Some species ARE hardy in a zone and then a new cultivar comes out and it isn't.

Check, check, and re-check with multiple sources. Is it available LOCALLY? Good local nurseries generally don't sell stuff they will have to replace if it's not gonna make it in their zone. Call your local Extension Office and talk to a Master Gardener (shameless plug!) - they generally have experience with most plants or know who does.

Also, if it makes ya feel better, each yard has it's own little micro-climate. You may be able to sneak in things that are delicate in your area because of the way your garden is situated, sheltered, etc. I have not had luck with this, but it's my fault - I don't baby the plants. They either live or die in my zone! HTH and wish I had a concrete answer for ya!

Good idea...Check with your local nurseries to see if they are available where you live...I know they don't some things here because they are more tropical, even though I can grow some tropicals :)

I looked through the 2003 Heronswood catalog (that year within reach) to see what Dan suggested for hardiness on these; he had listed Z5 for Thalictrum rochebrunianum, Scrophularia auriculata Variegata. You may find Phlomis russeliana marginal - do you have a full sun protected spot or could you offer some winter protection (Z6)

I agree with morz8 - both the thalictrum and the scrophularia are zone 5 plants and IME, the phlomis is even hardier (listed as zone 4 in several references). The old Heronswood catalogs are a great resource for this sort of information, but my fall-back resource for hardiness issues is the AHS A-Z Encyclopedia of Plants - it is notoriously conservative in its hardiness designations and it confirms all three of these.

btw, I've not heard scrophularia referred to as comfrey, and I'd want to make sure we are talking about the same plant - scrophularia is commonly called figwort (or sometimes, water betony) and appreciates damp, even boggy conditions. Comfrey or Symphytum is a particularly aggressive spreader/seeder, often to the point of invasiveness. I love my variegated figwort, but I'd avoid comfrey, even the variegated forms, like the plague.

Gardengal, do you know the phlomis? I found the site description unclear to me (and that's about as close as I come to a criticism of any of D's descriptions :) )

full sun, poor draining soil. Is that poor, well draining soil, or soil that remains moist and drains poorly?

Hi! Thanks everyone for writing! By the gardengal48, your right, it is Scrophularia not Symphytum (the two plants are next to each other in one of my gardening books, I must have gotten their names mixed up). The comfrey was intended for my compost, but im now thinking twice about it. I always do a lot of reaserch on a plant before buying it, so you can imagine my confusion when I read the tags yesterday. The tags are then clearly wrong. Thank you everybody! I am sooooo relieved (I seriously thought I had gone of the deep end, as it is unlike me to forget anything about plants I lust after).
CMK

Phlomis russeliana wants poor, well drained soil. It's very hardy. Thalictrum rochebruninum grew magnificently in upstate NY--a cold zone 5.

Christin, I believe Tony Avent of Plant Delights nursery has the right idea on this hardiness thing. A well known quote he uses is:

" I consider every plant hardy until I have killed it myself...at least three times."

Much hardiness is more a matter of soil moisture than true temperatures.

About comfrey, the Blue comfrey, often called caucasian comfrey is a beautiful and fairly well behaved garden plant. A bit invasive but easily controllable.

George

I've grown Phlomis russeliana easily in my Zone 5 yard in NE Ohio. The clump increases nicely each year.

Morz8, I have a theory about phlomis-like plants, those that have a fuzzy and grey or slivery tint to their foliage - they all like a hot, sunny situation in well draining, lean soil. Think verbascum, stachys, senecio and all the Mediterranean plants (rosemary, santolina, lavenders, etc.)

You must be looking at a different catalog, as mine (2000) says "full sun or part shade in well-drained soil."

Thanks everyone for the great advice; you have been very helpful! I think I really paniced when I saw those tags, as I had spent a small fortune on all of the plants. ;)
CMK