Flowering plants that stand up to dog urine need to be made of hardy stock. According to Scott Aker of the Washington Post, flowering plants that can withstand assaults by sea salt are theoretically hardy enough to withstand dog urine. Obviously, these plants can better withstand urine when frequently watered or rinsed. Plants that are subjected to dog urine should also be properly fertilised to keep them healthy enough to thrive under the conditions.
Rugosa roses are sea air-tolerant hardy rose plants that produce large, layered, single blooms from dark green leathery leaves. They are quite tolerant of cold, making them applicable to USDA hardiness zones 4 and 5. Rugosas grown outside of the proper zones tend not to be as tolerant of dog urine as those grown in optimal climates and conditions. Rugosa roses and rugosa hybrids, which tend to grow double flowers, are available in white, pink, red and purple blooms. Rugosas should be cut back in late winter to prepare for new spring growth. These rose plants have thorny stems, so place them carefully in your garden to protect your pets.
Knock out roses
Knock out roses will add hardy red, pink or yellow roses to your garden. They will tolerate dog urine and are extremely easy to grow. Hardy to the coldest temperatures in USDA hardiness zone 5, yet easily grown in hot dry climates, the knock out rose adds colour with minimal care to any garden. You can cut these roses back in late winter; once the roses bloom in spring, they continue throughout late autumn. Like the rugosa, the stems are covered in thorns, so plant these flowers carefully with your dogs in mind.
Drought and heat-tolerant flowering yucca baccata, also known as the banana yucca, is a small species of yucca that produces large plumes of yellow and pink-tinged white flowers. These plants can be easily grown in both arid and semi-tropical areas and are frost-tolerant during cooler months.
Considered xerophytic plants, yuccas can't hold a water supply like a succulent, but are extremely hardy and drought-tolerant. If you note any leaves that are brown at the tips or around the edges, which can be caused by the acids in urine, rinse them from time to time to minimise the damage. Most dogs will urinate on the outer edges of the plant and not the centre flowers.