Great Underplants for roses
Old roses combine particularly well with other flowering perennials and herbs. In fact I often grow all my vegetables for the year amongst the roses, tomatoes, broccoli, garlic, silverbeet, capsicums,lettuces, chives, thyme. All members of the onion, allium family also make good rose companions dettering other pests, even if they don't, the mauve flowers look nice amongst the roses and are good to eat. Being less disease prone old roses can handle being planted up close with other plants and these others keep on flowering after the roses have stopped or are taking a break. The underplants cover the ground making black spot (which comes from bare soil) less of an issue. Plus they keep the rose roots moist and stop the weeds, with 700 roses to weed myself I need all the help I can get.
The following are ones I use in my garden in a hot dry climate :
Scabiosas, evening primrose pink (be careful this can take over the garden), seaside daisy, erodiums, thymes, lamb's ear, santolinas, anthemis tinctoria, felicias, marguerite daisies, osteospermums, dianthus, carnations, arctotis, salvias, statice annual and perennial varieties, irises, daylilies, verbenas, gazanias, nemesia foetens, perennial wallflowers, diascias, wormwoods, perovskia, feverfew, chrysamthemums and nepetas.
Great old rose annuals flower companions I use are :
Shirley poppies, alyssum, lobelias, bellis perennis, violas, pansies, hollyhocks, larkspurs, wallflowers, nemesia, and cornflowers to name a few.