Weeds, Not Wildflowers: Part 3

The battle against invasive weeds never ends. Here are species that should be controlled in your natural area.

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Poison Hemlock (Conium maculatum)

Poison Hemlock, a biennial, is blooming with clusters of flat white flowers atop tall purple-blotched stems. A member of the parsley family, it has lacy compound leaves. A single plant may form upwards of 38,000 seeds. This plant is poisonous if ingested and was the hemlock used to poison Socrates.




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Teasel, Dipsacus sylvestris and D. laciniatus

Both biennials, Teasel is sending up flower stalks now along roadsides and fields from its deep taproots. Its leaves are large, coarse and spiny; clasping the stem to form a cup where water collects. Prickly flower heads appear in summer above needle-like bracts. The flowers then dry into a cone-like seedhead and form up to 34,000 seeds per plant. It will readily reseed if mowed in the fall and can form dense colonies.

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Birdsfoot Trefoil, Lotus corniculatus

This low growing legume plant is blooming now with brilliant yellow pea-like flowers above three-lobed leaves. It thrives in disturbed areas forming a deep root mass and dense mats of foliage that crowd out native species. It also spreads by seed, generating about 5,000 seeds per plant. Fire increases its germination, making it particularly tough to control.


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Purple Loosestrife, Lythrum salicaria

Purple Loosestrife is commonly found invading wetlands, retention ponds, roadside swales, and ditches and can get up to six feet high. It has a flower spike of pinkish purple blossoms and will aggressively form colonies, crowding out native plants. A single mature flower stalk can produce up to 300,000 seeds. Purple Loosestrife spreads readily by seed and can regenerate from root fragments. It was brought to the U.S. as an ornamental garden plant by Europeans. There are some loosestrife-eating insects available, but they cannot completely control the plant.


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Wild Parsnip, Pastinaca sativa

Wild Parsnip is blooming now in natural areas, disturbed sites, and roadsides. Its tall stalks are blooming with bright yellow flat flower clusters. Wild Parsnip typically is biennial with a rosette of ferny leaves the first year and a four foot high hollow grooved flower stalk the second. Flat oval seeds follow the clusters of blossoms. It resembles a yellow version of Queen Anne’s Lace. Be careful when dealing with Wild Parsnip. Its juice in contact with skin in the presence of sunlight may cause a rash or burn.


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Red Clover, Trifolium pratense

The round pink flower heads of Red Clover are blooming above bushy foliage composed of three-part leaflets marked with a pale green V shape. It has a fibrous root system and stems will root at the nodes when in contact with soil, allowing it to fill an area quickly. Commonly found in fields and meadows but readily invades natural areas and native landscapes. Red Clover tends to be between 8 and 20 inches high.


Are these weeds on your property? Contact us about developing a weed management plan today!

Weeds, Not Wildflowers: Part 2

Have you seen these weeds? These aggressive invaders are blooming along roadsides, in forest preserves, and in your own backyard. They are not native wildflowers and can smother our desirable species. Don’t let them get a toehold on your property. We can help! Share this so we can spread the word about invasive species.

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Garlic Mustard, Alliaria petiolata

Garlic Mustard is widespread throughout the Midwest. Reaching about two to three feet high when it flowers, it has clusters of tiny four-petaled white flowers. Garlic Mustard is biennial. The first year it forms a rosette of ruffled green leaves. The second year it flowers, sets seed, and dies. Being in the mustard family, Garlic Mustard produces thousands of seeds that disperse easily.


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Yellow Rocket, Barbarea vulgaris

Another member of the mustard family, Yellow Rocket has upright clusters of bright yellow four-petaled flowers above a rosette of dark green rounded leaves. It is also a biennial and flowers the second year. Reaching about a foot high when flowering, it sets hundreds if not thousands of seeds.




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Dame’s rocket, Hesperis matronalis

Dame’s rocket is most often confused with wild or garden phlox. However, dame’s rocket has alternate leaves and its flowers have four petals instead of five. It will flower in shades of lavender and purple in spring. Reaching about three feet high, it is also a member of the mustard family. It spreads by seed and by roots.



Wild Chervil, Anthriscus sylvestris

Mostly found in Kane County, Wild Chervil is spreading rapidly. At between three and five feet high, its flat white flowers are reminiscent of Queen Anne’s lace, but bloom earlier and are not as tightly clustered. The ferny foliage reflects its heritage in the carrot family. It’s commonly found in roadsides, ditches, and forest edges.


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Lesser Celandine, Ranunculus ficaria

A member of the buttercup family, this short bright yellow flowering perennial spreads by roots rather than by seed. Rosettes of shiny green leaves are commonly found in moist edges of forests. It can be confused with the native marsh marigold, but Lesser Celandine has narrower petals and green sepals.

If you’re dealing with any of these invaders – contact us to set up a weed management plan.

Weeds, Not Wildflowers

Invasives are everywhere! Here is a selection of common species that should be controlled in a natural area.

Image result for common ragweedCommon and Giant Ragweed (Ambrosia artemisiifolia and A. trifida)

Common Ragweed is a short annual at around three feet with ferny foliage and a greenish yellow flower spike. Each plant produces 3,500 seeds per year. Giant Ragweed can range from three feet up to 10 feet tall! Its large mid-green leaves are lobed in patterns of three or five. Firm flower spikes are yellowish green and form at the top of the plant for maximum wind dispersal. Each plant can produce up to 10,000 seeds. Ragweed is the bane of allergy sufferers in late summer and early fall with its copious pollen release.


Chicory (Cichorium intybus)

Chicory is that cornflower blue flower you see flourishing along roadsides, fields and can invade prairies. It is about a foot tall and has clusters of blue blossoms with squared off petals. It forms a rosette of hairy leaves and a deep tap root. Chicory tends to appear here and there, then in a couple of years can blanket an area. Biennial to perennial, it is native to Africa, Asia and Europe. Each plant can produce up to 3,000 seeds.


Queen Anne’s Lace (Daucus carota)

A biennial, Queen Anne’s Lace is often regarded as a beloved wildflower of roadsides and disturbed areas with its flat white delicate flowers and carrot-like foliage. In fact, it is native to Europe and Asia and can dominate prairies to the detriment of native wildflowers. Queen Anne’s Lace can produce up to 40,000 seeds per plant that can live up to two years in the soil, making it a persistent threat.


Common Reed Grass (Phragmites australis)

Common Reed Grass turns rich wetland habitats into monocultures that can change marsh hydrology and become fire hazards. It can reach up to 15 feet high with alternating green leaves along a hollow stem. It is blooming now with reddish flower plumes. It primarily spreads by roots and a single stolon can grow 10 feet in a year. Roots have been found up to 43 feet away from the main plant. Common Reed Grass also produces thousands of seeds per year. It requires aggressive treatment to eradicate.


Cattails (Typha x glauca, T. latifolia, and T. angustifolia)

Cattails rapidly fill in wetlands, basins, swales and ditches. The brown sausage-like flowers are blooming now above thin leaf blades. Spreading by thick colonies of starchy roots, they can be tough to eradicate. Because they can form large stands quickly, Cattails choke out native wetland species and can create monocultures not beneficial to birds and insects.


Are these weeds on your property? Contact us about developing a weed management plan today!

Featured Project: Graceland Cemetery

Chicago, IL — Today, an historic cemetery is breathing new life within its grounds. The trustees of Graceland Cemetery in Chicago wanted to recreate a piece of the tallgrass prairie that once covered much of the region. Native plants and landscapes were an inspiration to O.C. Simonds whose innovative designs made the cemetery into a peaceful, pastoral place.

On an approximately two acre site, Pizzo & Associates, Ltd. was contracted to create a pre-settlement prairie. After removing the turf grass, and a summer season prescribed burn, the area was ready to install our custom Low Profile Prairie seed mix. Using hand seeding, we covered the area thoroughly and raked it in for good soil contact.

The first year the annual flowers and cover crop flushed into bloom, quickly creating the feel of a prairie. We then did supplemental seed installation and selected plug planting. Now in its second year, the prairie is lush and inviting. The prairie has become a highlight for the tens of thousands of CTA riders who view from the tracks above.

“I want to say that the prairie planting Pizzo did at Graceland Cemetery in 2014 looks stunning, almost overwhelming, considering it was seeded a little more than a year ago.  Everybody who is involved with the project is blown away by how quickly it looked so good.  This includes, I’m sure, if I could only hear them, tens of thousands of riders per day on the CTA Red and Purple Lines, who look down into the cemetery on their way to and from the loop.

You have done well by us, and we love working with Pizzo.”

–Ted Wolff, Landscape Architect