I cant bring the coleus in and I was wondering if I could just cover them when it hits 40?
Certified GKH Gardening Expert
They will not surivive outdoors over winter. You can bring it indoors for overwintering (treating like a houseplant) but many people simply choose to take cuttings and keep them over winter instead. This article will help: https://www.gardeningknowhow.com/ornamental/foliage/coleus/overwintering-coleus.htm