Shooting today for GardenShorts.com at Wave Hill. One of the continent's most thrilling hunks of property, not least because the into-the-vista setting feels like Tuscany but is in the Bronx. Under cultivation, one way or another, for a couple of centuries, but only in the last fifty years have its gardens reached their current dizzying heights of sophistication, density, and extent. Sigh.
Here's a shot along one of the paths in the so-called "wild" garden...
...which doesn't mean wild in the sense of anything goes, the loucher the better. Nor wild in the sense of untouched let alone untamed. It's the layout that's wild, scrambling around a rocky slope on narrow winding gravel paths. Great horticulture crowds the pathways, and as everything soars higher and higher in Summer it becomes a full-body experience. In Spring it's great to have perennial plants that get high fast, when everyone else can be just building up a head of steam. In particular, these tall billowing heads of small yellow flowers. Which I couldn't identify off the bat—a thrill right there: Something new, something else that must be grown myself.
And in this picture the GottaGet is Isatis tinctoria.

Despite the brilliant yellow of the flowers,
isatis is one of two naturally-occurring sources for the deep-blue dye indigo.  (Tropical indigo, Indigofera tinctoria, has flowers that are a mild pink, but nonetheless the plant is loaded with the very same indigo dye, and in much higher concentrations too. In both plants, the dye is extracted from the leaves.) The large and early and many-many-small-flowers bloom heads are a tip-off, or rather a warning, that isatis is a biennial.
It's mission above all is to produce a zillion seeds early in the season, then die and let the seeds have at it.
Isatis is a noxious weed in several Western states, and while it's in the wild all over the East, apparently it's not a thug. So yes, I'll give it a try. If the self-seeding isn't a nightmare, the height and happy yellow of the flowers would be a delight. We'll see....