Fuse the pieces together as one unit that layer on top of each other. I just applique those pieces to each other (red flower buds to green bud leaves; white circle - light green flower - dark green flower). After that, you can fuse everything onto the background & just applique stitch around the outer edges (I'd use green so it blends with the leaves/stems, but contrasts with the flowers and hearts). You should be able to go completely around everything except the floating circles in one pass that way without breaking thread. You will, of course, need to stop & pivot a lot to get the right positioning for your stitches, and you'll want to shorten the stitch length as you get to the points of the leaves and inner/outer points of the hearts, but it's definitely doable with just breaking thread 5x if you've already created your units.