This pattern is number 20 from Rosemary Drysdale's The Art of Blackwork Embroidery, adapted a little in that I shifted each line of medallions so that they nested together a little and left less white space.
Free Blackwork Design: Autumn Leaves on a Corner here is a leafy corner, just in time for autumn (on this side of the world). Of course, if you imagine the leaves green, it could also be just in time for spring and summer!
blackwork fill-in patterns from Lesley Wilkins Beginner’s Guide to Blackwork - cross stitch I've been planning a largeish-scale blackwork project. These may come in handy.as an alternative, use a different colour of embroidery floss.