It probably depends on how bad your summers are and whether you can water them appropriately and check them often. Over here in TX, I would mulch them and keep them potted in a bright place with little or no sun & little or no wind. Then when the temperatures go down from the 100s, I would plant them. Technically, you can plant them now but it is just too stressful for anything to be planted now. I have to be back inside the house by 10-11am (too hot).