**This is a guest post I wrote for the Beautiful Wildlife Garden Blog**
Be sure to check out this collaborative (and informative) blog.
This week is National Invasive Species Awareness Week
We have at least another month before we'll start to see bare ground here in Minnesota. During a January thaw, the snow on our south slope melted away for a couple of days. I looked out our kitchen window and saw a couple of bright green Garlic Mustard (Alliaria petiolata) rosettes looking as fresh as ever. Boy, was I mad.
I had gone over our yard with a fine tooth comb in late fall making sure there wasn't any Garlic Mustard. But, it's a sneaky biennial - I'm convinced it grows under the snow all winter developing its carrot-like tap root. Then it laughs at you in the spring when you try to pry the rosette out before the ground has thawed and the tap root snaps leaving the majority in the ground to regrow again.
Garlic Mustard has become a highly invasive plant of woodlands on both upland and lowland sites in most of Eastern North America. It tolerates a fair amount of shade and can quickly spread through understories and woodland edges crowding out native plants. It is also a common weed in urban areas.
The four petaled white flowers form on two to three foot flower stalks that arise from the basal rosettes in the second year. Flowering begins in early spring - the beginning of May in our neck of the woods.
A large patch of Garlic Mustard can be overwhelming if you have a large property. I regularly organize "Garlic Mustard Pulls" in the neighborhood to help out homeowners who are overwhelmed. It also provides an opportunity to talk to and get to know your neighbors. You can also tell your neighbors about the great things going on in your wildlife garden.
Offer them a tour of your garden and show off how many butterflies or birds are visiting your landscape. Talk about other invasive plants in the community to look out for too.
It's really amazing how a group of 5-10 people can make a difference for even an hour's work.
How To Get Rid of It
Start by pulling the stragglers (the isolated plants that are furthest away from the main cluster) and work your way towards the largest patch. This eliminates any more "outlying" seed being produced by the stragglers. Eventually, you will be pulling from the original patch area until the seed bank exhausts itself.
Since this is a biennial, eradication means pulling the plant up (including all of the taproot) before the seeds mature in their long narrow pods. If the seeds have not formed you can prop the pile of plants against any object (log or low branch) with the taproots up so that they are not touching the ground (the taproots will sometimes reroot if allowed to be in contact with the soil).
If you're too late and the seeds have matured, cut the seed heads off, bag them, pull out the plants and leave everything but the bagged seed heads.
We had a significant amount of Garlic Mustard on our property when we moved in seven years ago, but now I only pull 10-15 plants in the spring (once the ground has thawed of course).