Gardenias are hardy shrubs with deeply fragrant white flowers. Although they tolerate many conditions, including sun and shade, gardenias are sometimes picky and do not always tolerate hard freezes. Regardless, the glossy green leaves and attractive scent of the flowers make them a prize with many home gardeners. You might notice your gardenia was damaged after cold winter weather. Occasionally this could mean a loss of the plant, but if they are only partially frozen, gardenias revive easily.
Gardenias are resilient plants that can survive frost, but deep freezes and temperatures below 15 degrees F can cause damage and kill parts of the plant. Wait to see if the plant puts on new leaves once temperatures climb in spring before removing any branches. If it does not, then the plant likely has not survived the freeze. Frost can damage parts of a plant but will not kill it entirely, especially if roots are protected. Damage could be superficial, causing nipped leaves without killing flowers.
What To Do
Remove any piles of snow or ice that have built up on the gardenia plant. Prune broken branches. Once spring arrives, wait for new growth and cut off any dead wood that remains. In many cases, a new flush of growth will occur at this point. Treat the leaves with a chelated iron product if they are not a bright green color. Protect from future frost damage by covering it in cold weather, and the plant likely will thrive for the rest of the year.
Gardenias are more susceptible to frost damage when grown in a container, where the root zone is not insulated. Once temperatures outside dip close to 20 degrees F, it is a good idea to move a potted plant indoors. Planting in the soil or near a house helps to prevent cold damage. A springtime planting allows it to develop a strong root system, making it more hardy come wintertime. Select cold-tolerant varieties such as Frost Proof and Jubilation.
Water to keep soil moist but not saturated. A location with plenty of morning sun and little afternoon sun is best. Prune as needed after blooming time. If you prune too late in the year, you could make gardenias susceptible to winter frost by removing their natural insulation. Well-drained, acidic soil in full sun or partial shade helps these flowers thrive.