Check out: http://www.thegardenlady.org/2009/05/25/propagating-lavender/.

There are times when plain old Common Sense has to come into play, and this is one of them - and you are on the right track. The idea of the plastic cloche is to create heat and humidity - but if you've already got both in abundance, then why bother with the cloche? The cloche acts as a hot-house. Hot houses are usually very large and they have a LOT of space to ensure that plants don't touch the hot sides and tops. If you create a miniature hot-house with a plastic cloche, it needs to be several times larger than the pot under it. Yes? And of course, it helps to keep the temperature inside even. As long as you don't get large fluctuations in the temperature during a 24-hour period, your cuttings should strike well. Keep in mind that hot-houses exist even in the hot and steamy tropics. In this situation, they enable EVEN and CONTROLLED amount of heat, water and air-circulation, as required - ie not dependant on outside conditions. Or to put it another way - a hot-house is an attempt at providing plants with their preferred PERFECT conditions.

Carla, LP is a good rose. Mine doesn't bloom as much as I'd like, but it's in a section of the oddball bed that needs some amending. The plant is still not very big, even tho I've had it for quite a few yrs (it's own-root). When it blooms, they're very pretty, and open up kind of loose and "sloppy" but look kind of "Victorian." Here's a few more pics:

Thank you Darlene! Everything I've read has said to take the new tender growth, so that's interesting. I will try taking some more hardened growth next... I'll try anything at this point. It looks like, out of at least 28 cuttings, I may have one survivor holding on... so... progress? Not exactly the 90% success rate that everyone talks about :( Ultimately, I'm hoping for about 4 or 5 Lavender Cotton plants to fill in one space of my garden and 4 more of my Munstead Lavender to finish out a small hedge. Definitely too hot to try and root them outside right now - though I did try it for some of the lavender cotton (it was doomed from the start). I've been hoping that starting indoors will have more success - I'm also going to try a lighter seed starting mix next instead of the potting soil. I will try a few out in the garden soil this fall to see how they do. I've got a few more sheltered places in the garden where they may survive. When they do finally root outside, do you dig them up and move them, or are you rooting them in small pots outside that can be moved around?