Dame’s Rocket is considered invasive and is illegal to cultivate in three states. Fortunately, Vermont is not one of them, because hesperis matronalis is, in my humble opinion, a very useful and important plant in a cold climate permaculture scheme. Rocket is fairly well known as an ornamental, and is a survivor (and, yes, escapee) of long abandoned flower gardens. It is a crucifer, a member of the mustard family, but few gardeners realize that it is an edible cousin of those nutritional powerhouses kale, broccoli, and cabbage.
Rocket is reputed to sometimes be a short-lived perennial, but is mainly biennial. What I really like about it is that its foliage survives winter well with no protection, lots better than kale leaves do for me. This makes it one of the very first sources of spring greens available to us. As soon as the snow melts, you can push aside the tattered old leaves and find tender green shoots hiding beneath. All through spring, we pinch off tender new leaves, shoots, and unopened flower buds for salad; and in June the blooms are fine garnishes as well, not to mention fragrant cut flowers.
Herbal authority Maude Grieve lists it as antiscorbutic, which implies that it is very high in vitamin C. The leaves have a slightly acrid after taste, that may be off putting for some, but I find it pleasant. It mixes well with other salad greens, but I think the trick is, as with so many greens, to harvest only tender new growth.
Rocket is a managed volunteer in our gardens. Its growth cycle is easy to integrate with vegetable plantings. We leave a few first year seedlings growing here and there around the garden when weeding. They take very little space the first year, and in the spring occupy what would otherwise be empty space. (The tender weedlings are also good in salad.) Rocket begins flowering just as we get past any likelihood of frost, and when the space is needed for frost tender plants. By that time it not as useful for greens, so a few very robust plants are chosen for seed and staked up. The photo at left shows the nearly mature seed pods on a staked plant. The rest of the plants throughout the gardens are pulled as the space they occupy is readied for planting other things, though some plants get to linger past blooming to ensure maximum pollination of the plants that will be left to bear seed.
And why, you may wonder, would anyone fuss about seed from an invasive weedy plant? Well, copious seed production is what makes hesperis matronalis a pest, but the seed happens to be fine for sprouting. It is a little sharp in flavor, but mixes well with milder sprouts, and other salad elements. For sprouting, you don’t even have to bother to clean the seed thoroughly, you can just float off the trash as you make the sprouts.
Outlaw, maybe, but I think she’s a classy dame nonetheless!