Lily bulbs like good drainage so they're not sitting in water; excessive watering can cause bulb rot. Doesn't seem to be the best pairing for roses with the wide swing in water requirements.

You could plant in "like requirement zones" rather than interspersing. Or you could hand water the roses in an attempt to regularly bypass the lilies. With roses, I'd probably look into moisture/sun loving plants like Siberian iris, heucheras. Even hostas, astilbes, forget-me-nots, trollius, less invasive ferns... I've found that here in zone 4, I can grow the more shade tolerant perennials in full sun conditions without ill effects. My experience only, others may differ.

This is not nearly as complicated an issue as you would think. Roses and lilies are not an unnatural pairing - both will thrive if provided with adequate but not excessive moisture. The key is soil quality and good drainage, which both will appreciate - this where that common gardening conundrum of "well-draining yet moisture retentive soil" comes into play - a loose, fertile soil, well amended with organic matter. Roses are not necessarily moisture lovers, neither are clematis. Both will grow with moderate and ordinary summer irrigation, much the same as one would provide for a whole host of other perennials, shrubs or vines.....and lilies. I grow a large number of all three interspersed in what could best be described as a mixed border.....somewhat akin to a cottage garden.

Roses and lavender are a different matter, however. They don't share the same soil requirements or nutrient demands and lavender is definitely a xeric plant, preferring to remain very dry most of the year.

Thank you for your opinions. My soil is quite nice from many years of top dressing ie mulch, leaves, horse manure ect. All of my beds are at least 8 or more inches above ground level. I'll probably try a few and see how it goes. Thanks again, Pat

Hi Patty, I started out with lilies about 10 years ago and this last year I mixed in some of my lilies where I had planted my new roses and they did great. Like I said though last year was the first year with roses so I am sooooo new to mixing these but you might want to check out the rose forum too and look at some of their combos and check with someone over there about their opinions too. My zone is way different than yours so that might make a difference too. Good luck and have fun trying different plants. Judy

Hi Patty, Most of my lilies are daylilies so I don't know if that makes a difference or not. Judy

Thank you Judy, I mixed my daylilies with the roses last year also. So many of my roses are young and need more water than they will when estabished. I did read thou that daylilies can take more moisture than lilium. Actually had taken out a lot of my daylilies. Tossed them by compost but the following spring they grew anyway and by summer started to bloom. Felt sorry for them and replanted. Besides if they start to look rattey after bloom, I just cut them back and they regrow providing extra compost. Thanks again, Pat

Lilies are 'lilium' and daylilies are 'hemerocallis', so very different plants with different needs. Daylilies would be more suited to rose conditions, as lilies like it on the drier side.
However, to overcome this, with my heavy clay soil, I use drip irrigation and can control the amount of moisture for each plant. My setup is not fancy and is not automatic, but it works great. I use black 1/2" pvc hose and poke drippers in it where I want water. I leave the hose in place at all times and when I need to water I simply connect to the main garden hose.
Simple but effective.