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Garlic mustard...space invaders!

SPACE INVADERS!

You've likely seen this one in your yard, your neighbors' yards, in the woods, on the side of the road, and so on. Garlic mustard (Alliaria petiolata) produces copious amounts of seeds and is "allelopathic", changing the soil with biochemicals to prohibit the germination and growth of other plants. It's a "biennial", living two years and generally producing flowers and seeds in the second year. But its "offspring", from those copious seeds (we weren't kidding!), create a dense carpet other species can't compete with.


 

PHOTO IDENTIFICATION

Garlic mustard generally grows at the edge of woods in disturbed soil in part shade conditions. Although it grows most vigorously in moist conditions it will still grow prolifically in any soils. Which is why you'll see them in your yard, your neighbors' yards, in the woods, the side of the road...you get the idea.



photo 1 by Alan Wolf, 2 by Katja Schulz, 3 by Robert Flogaus-Faust


 

HOW TO REMOVE:


The bad news: garlic mustard contributes intensely to the seed bank (the viable seeds on and in the soil from previous year's plants). The seeds remain viable in the soil for upwards of 10 years so you'll need to pull this species for a few years. It took me 4 years in my yard to completely eradicate the garlic mustard. But it wasn’t as daunting as other invasive species in my yard (I'm looking at you bishop's weed!). 


The great news: The taproot is relatively easy to remove with one pull and shouldn't regenerate from any fragments left. Random fact: If you keep chickens, they love to eat the leaves before it goes to seed (obviously know the background of the area and that it hasn't been sprayed with chemicals). You can also routinely mow garlic mustard down to keep it from flowering and producing more seed.


Once pulled, don’t put these plants in a compost pile, especially if they have seeds. Bag them to dispose. If you enjoy pulling these check out the event link at the bottom of this page, "Weed for Wildlife in Cohasset, MA on May 5.


 

WHAT TO PLANT:

"Nature abhors a vacuum", so either you need to plant something as a replacement or whatever seed is already there will fill in the gaps. We recommend after pulling out garlic mustard that you plant native plants that tend to be strong growers. These will shade the ground and keep a lot of the viable garlic mustard seeds from germinating. Some of our favorite natives that have similar growing conditions to garlic mustard.


Can cover a larger area relatively quickly and has shown not to be too bothered by the biochemical soil changes. These plants send out runners, much like a strawberry plant, and can cover a larger area relatively quickly. Tiarella cordifolia thrives in moist soil, perfect for a humusy woodland edge. The foliage is bright green and delicate flower spikes appear in the Spring.


This spunky little plant has low growing heart-shaped leaves and sends up a spike of bright yellow, daisy-like flowers that will brighten up any landscape. If allowed to colonize, this plant can serve as a suitable ground cover for areas that receive sun to full shade and regular moisture. Excellent for a woodland garden.



This native spreads quickly by rhizomes, preferably in moist, rich soil in partial shade to full sun. While you might want to rethink placing it in your front garden beds, you definitely want a native plant that can hold it’s own against garlic mustard. Perfect for naturalizing moist areas, it is also a very cute, flowering plant with bright green leaves that add great texture to the landscape.


Stays green year round. Easily established in the proper conditions, this fern makes for an excellent four-season accent plant in shade gardens. Unlike some other ferns, this one does not tolerate standing water, rather, it thrives in moist soils with good drainage, but it is also surprisingly drought tolerant.



Solidago flexicaulis (Zigzag Goldenrod)

This lovely goldenrod (no they don't cause seasonal allergies!) reaches heights of 2-3 feet and features beautiful yellow flowers that bloom in late summer and early fall. The unique zigzag pattern of its stems adds visual interest to any garden, making it a great choice for borders or naturalized areas. Zigzag Goldenrod is easy to grow and low-maintenance, thriving in partial to full sun and well-drained soil.


Matteucia struthiopteris (Ostrich Fern)

A stately, vase-shaped fern that grows between 3-5 feet tall and has a 2-3 foot spread. A dramatic addition to a shade garden during the summer months before falling dormant by early fall. Notably, the early growth of these ferns are called “fiddleheads”, and are edible (but always do your own research before consuming any plant from your garden!).



An important nectar source for hummingbirds and pollinators. Best suited for light sun/part shade areas, you likely won’t see flowers until the second year after planting. Once the showy red and yellow flowers emerge, you will delight in watching the myriad of wildlife attracted to them. With the right soil, these plants will willingly self-seed into a large colony, and if we happen to have a cooler summer the blooms may remain well into July.



 

Happy garlic mustard pulling!

Britt



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