Here is a another beautiful, and easy, linear stitch suitable for plants.
Alternating Chained Buttonhole Stitch is similar to the Zig-zag Petal Stitch, but is quicker and a smart way to make a stem and leaves/flower buds at the same time. The stem is also thinner than that of the Zig-zag Petal Stitch.
It was Deepa of 'This and that... my random thoughts' who taught me this stitch, here is a link to her blog with pictures. Do visit!
Stitch it like this: