ox-eye daisy - invasive

 

Ox-eye Daisy Leuceanthemum vulgare is a perennial herbaceous species with a creeping root system. 

This daisy is not native to Minnesota, but imported as an pretty ornamental flower. 

It turned out to be an aggressive invasive species. Once established, it can spread rapidly by means of roots and seeds, and block sunshine for other native wildflowers.

velvetleaf

Many plants, which bloom and fruit in the warm growing season, stand bravely throughout the winter to ensure its seeds are fully distributed.  This fruit capsule opened as it dried out in Autumn, and seeds have been coaxed out by the breeze.  Now, it stands despite snow and hoarfrost.

Velvetleaf Abutilon theophrasti blooms in late summer with orange-yellow flowers on stems and leaves that really look and feel like they are cloaked in velvet. There were a few growing in the riparian buffer around the pond, but we pulled them because this plant is not native.  It can form dense monocultures in place of native plants, suck large quantities of water and nutrients from the soil, and can inhibit germination of other plants.

This in one of the plants that probably spreads from nearby crop fields, and that we try to keep out of the pond area.

protecting native plants

You might see me pulling weeds, snipping tree sprouts, or clipping seed heads in the riparian buffer surrounding our pond.  This is necessary to protect the pollinators, birds, and critters that depend on the native plants and the clean water in the pond.  Fortunately, we have a wonderful variety of native wildflowers close to the pond that have been thriving and propagating for several years.

Unfortunately, the builder brought in soil during the last 12 months to finish the area beyond the native plantings. That soil contained a plentiful seed bank of invasive or harmful species. We now have a bothersome crop of knapweed, velvetleaf (shown above), mustard, ragweed, lambs quarter, crabgrass, dock, amaranth, spurge, and thistles surrounding the pond.  They are competing with the desirable native plants like milkweed, aster, lobelia, boneset, chamomile, clover, daisy, echinacea, golden alexander, meadow rue, bee balm, penstemon, ironweed, mountain mint, vervain, silene, sunflower, and others. 

To protect them, you will see me pulling, snipping, and clipping.

knapweed

Unfortunately, everything that looks appealing is not a good thing.

This plant opened its blooms this week with a pretty show of purple among the other wildflowers in the pond area.  We had watched this plant through Spring because we did not see it last season here.

Despite its interesting bloom, Spotted Knapweed Centaurea stoebe is on the Minnesota prohibited weed list. Knapweeds are invasive plants that can out-compete native plants with chemicals that poison the soil and inhibit native plants.

Note: This is a non-native invasive plant that can compete with native wildflowers.  Letting it grow here will reduce the good quality wildlife habitat in the natural wetland around our pond.  We will be removing it.

queen anne's lace

Queen Anne's Lace Daucus carota is a member of the carrot family.  There are several of these tall striking 'wild carrot' plants in the disturbed area around the pond. 

Each bloom is an umbel of small flowers that form a shape like an open umbrella.  Its flower looks like poison hemlock or wild parsnip, two plants you want to avoid.  The few small magenta flowers in the center help identify Queen Anne's Lace.
(photo left)

It is interesting and pretty, but if allowed to proliferate it can crowd out native wildflowers. 
We hope to limit Queen Anne's Lace spread by  clipping the flowers just before they go to seed.  Meanwhile, we can enjoy the white (sometimes pink-tinged) blossoms.

full bloom thistle

The Musk Thistle Carduus nutans I've been watching since May is now blooming.  The plant is more than 5 feet tall and branched out regally to stand above the other flowers near it.
Several blooms, each opening in their own time, reveal deep magenta color at first.  (See 6/7/2020 and 6/17/2020.) Then, as the flower head ripens, it seems pale lavender. The plant flowers over a seven- to nine-week period, and begins to disseminate seed about two weeks after it first blooms. 
Note: This is a non-native invasive plant that can compete with native wildflowers, so we will try to control the seeds.

thistle

We have been watching this thistle plant, while removing the other "field" thistles from the wetland area.  Probably 'Musk Thistle' Carduus nutans, or ‘Plumeless Thistle’ Carduus acanthoides, the seed germinated last summer.  It over wintered as a rosette protected by leaf litter and a cover of snow.

We noticed this rosette among the ground clutter after the snow melted.  Through May, it resumed vegetative growth.  It is growing tall now, and branching out to produce numerous large flower heads.
This particular plant is just a lot of green now, hiding among more green.

But when it finally blossoms, you will not be able to miss the deep purple magenta flowers!

After blooming and setting seed the whole plant will die, thereby completing the life cycle.
But this plant can produce 120,000 seeds that could germinate this season and form little rosettes to wait out winter.  Rather than allow this species to spread and become a nuisance in the pond area, DNR recommends control before flowering.  We will enjoy the beginning of flowering and try to cut off development of any seeds.

blue vervain

Blooming in late summer, the Blue Vervain's tiny 1/4" flowers grow on floral spikes about 5" tall.  This native plant Verbena hastata appeared in the part of the woods recently cleared of invasive buckthorn and some other trees.  As often happens when buckthorn is cleared, the increase in sunlight makes way for native wildflowers to thrive.