Our Rugosa Rose bush (I think this is the species) came up beautifully this spring and now looks like the attached photo. The green leaves and new leaf buds recently started to wilt and some are even turning yellow. We have never had a problem with this hearty plant before, it is always so lush every year and loves the spot we have it in. It receives a lot of sun and produces the most beautiful light pink/white roses. Any assistance would be helpful as we want it to survive!
Thanks for contacting Toronto Master Gardeners. Rugosa roses are known for their incredible hardiness and legendary disease resistance; but they are vulnerable to certain diseases and pests. It is not possible to make a definitive diagnosis from your photograph but two pests/ diseases that turn rugosa leaves yellow in the spring are aphids and verticillium wilt.
Check the underside of the leaves for small bugs. If aphids are present they can be removed with a strong blast from a garden hose. For other strategies for ridding plants of this pest, please review the Canadian Government website on aphids
Unfortunately roses are also susceptible to verticillium wilt. It is a fungal disease that damages a plant’s vascular system. Foliage turn faded green, yellow, or brown and wilt on scattered branches, and entire plants may die. In some plants, (but not all) peeling off the bark on newly infected branches may reveal dark streaks following the wood grain. To manage verticillium wilt, support the shrub with adequate watering and an application of a slow-release fertilizer to promote new growth. Prune back dead branches and discard them in the garbage rather than with plant waste.