Galium odoratum aka sweet woodruff

Galium odoratum --sweet woodruff

Formal plant descriptions on major university websites are rarely enthusiastic, even more rarely lyrical.  So when you read that a plant is "very attractive and fine-textured in foliage" or "smells like sweet freshly-mown hay," you might be curious.  Add in "almost unique in the landscape" and "exquisite, whorled leaves," and you've got a plant worth knowing more about. 

The plant is sweet woodruff (Galium odoratum) a part- to full-shade ground cover of the madder family.  Originating around the west end of the Mediterranean where Europe, North Africa and Asia crash into one another, the plant crept on its shallow stolons to northern Europe.  In Germany, it became a medicinal herb and flavoring, used most famously to flavor May wine ("Maiwein.") 

A subtle scent is inherent in the plant itself--its leaves and stems--and is therefore present all year long, not just at flowering time.  Some people (and lucky me, I'm one of them) seem to be able to pick it out from a great way off, even on cold days.  However, others don't seem to be able to smell it, not even by rubbing or tearing the leaves--I was raving to two of my neighbors about this plant and neither got the scent. Yet it is no figment of my imagination.  The "odoratum" part of the plant's Latin name refers to this delicate scent, so distinctive, so sweet, a scent I will never willingly be without.

A common use of this plant even so recently as a half century ago was pillow-stuffing.  These pillows were particularly thought to help children sleep.  Woodruff was also traditionally classified as a "bedstraw," because when people slept on straw mattresses, its fresh odor was evidently much appreciated. 

The color of the plant ranges from old leaves of dark green through bright, almost chartreuse, new growth. The leaves are arranged in overlapping layers, creating an intricate texture. The white flowers, in substance much like tiny wood-violets, make a very pretty (although short-lived) display in its mid-spring bloom season.  A dense mat of these has been described as "briefly spectacular."

The plant, which is about 4-5 inches high, creeps about the top layer of soil, sending out runners which develop tiny plants at each internode.  Although this sounds like a creeping menace (and its cousin G. aparine is a terrible weed) woodruff itself is not generally considered invasive.  To the contrary, sweet woodruff is not very good in the heat, so the problem here in Wisconsin is how to get it through the hot summers between its annual spring bloom and the time of its usual annual autumn revival.

Stated otherwise, a hot dry summer may make woodruff disappear entirely, having gone dormant until it revives again, generally in fall, but sometimes only the following spring. The plant is hardy in zones 4-8,  and the plant ought to be in deeper shade, the further south you go. Although it grows under trees, it does not do well with wet heavy leaves on its crowns, and can be smothered out of existence if these are not kept off. Similarly, although it grows pretty much where hostas grow, flopping dead hosta leaves can wipe it out.

Woodruff is said to like acidic soil, but it grows reasonably well in my garden where it must live in soil only barely acidic ("blue" hydrangeas come pink here).  Similarly, it is said to require a moist rich soil, but here tolerates a reasonably dry, reasonably lean soil. Deer are said not to like it.

One last thing:  Although sweet woodruff has long been used in small amounts as a flavoring and is generally regarded as safe for that purpose,  the sweet scent comes from a compound which is the precursor to many powerful drugs. So don't eat the plant itself, OK?