The Weed Detective
The Weed Detective
Nancy Reynolds, Delaware County Master Gardener
Visit the Weed Profile page for details about common weeds...
Mistletoe (Viscum album) December 2021
Did you know that mistletoe is considered a weed in locations where it grows naturally? Did you know it is one of only 2 parasitic plants that grow naturally in the United States? Did you know there are over 900 varieties of mistletoe that grow worldwide?
Mistletoe or Viscum album is a parasitic plant that grow on a variety of host trees and shrubs. Popular host trees are hawthorn, apple, poplar, lime and conifers. Mistletoe sends its roots into the tree and draws out nutrients and water.
Mistletoe can be identified by their many-branched stems that are swollen at the nodes and brittle. Leaves are opposite. The common Christmas variety has leathery, evergreen leaves and is covered in white berries through winter and spring. Flowers are inconspicuous, unisexu-al, and lack petals. The berries are one-seeded, white and have a sticky pulp that adheres to the beaks of birds that feed on the fruit.
The white berries are poisonous and cause gastrointestinal irritation, diarrhea, and cardiovas-cular issues. I’m pretty sure these are the same symptoms as Christmas Cookie overload so it can be hard to tell the symptoms apart! Keep mistletoe away from children.
Osage Orange (Malura pomifera) November 2021
One of the signs that we are deep into autumn is when I see Osage oranges on the ground. But are they a weed? Are they a “good” plant?
Officially known as Malura pomifera, Osage oranges are also known as hedge apple, horse apple and monkey brains! They have a textured fruit that commonly falls to the ground in mid- to late October, which is why it is this month’s topic. Although it is edible, it is also unpalatable due to its bitter flavor and an unpleasant latex-like liquid that irritates the skin.
Here are some good things that can be said about Osage oranges:
The oranges have an insect-repellent property, especially against spiders. As a result, they are used as an indoor décor item in the autumn when spiders invade.
Historically, Osage orange trees were known for their durable, decay-resistant wood. The Osage Indian tribe constructed their best and much-prized bows from the wood.
As settlers moved west through the Midwest and plains states, Osage orange trees became the premier fencing material along property lines. The trees have sharp spines; the twist-ing branches would be interwoven to create a living, armed fence. These fences would mature in just under four years and kept animals within property lines.
Osage orange trees were planted for thousands of miles and were one of the most sought-after trees at one time. The tree's popularity quickly faded with the invention of barbed wire, which was rumored to have been modeled after the thorny Osage branches. With time, Osage orange trees fell out of favor and are now considered by many to be a woody weed, made difficult to remove by their long, sharp thorns.
Osage Orange (Malura pomifera)
Goldenrod and Ragweed October 2021
I was reading a novel a few weeks ago and the main character decided to scare away her unwanted suitor by having him “help” her in the garden – once she realized he didn’t know the difference between goldenrod and ragweed. He was highly allergic to ragweed. I laughed hysterically – until I realized that I, too, have made that mistake. The 2 plants bear some similarities and grow at the same time, often in the same location. Although there are 20 or more species of each growing in Ohio, I am focusing on Common Ragweed (Ambrosia artemisiifolia) and Tall Goldenrod (Solidago altissima). So, here we go >>
Broadleaf plantain (Plantago major) September 2021
I used to have a tree lawn. Then, sewer work tore up the front yard near the road. Last week I realized I no longer have ‘lawn,’ I have a huge patch of Broad-leaf Plantain.
Broadleaf plantain, Plantago major, is a perennial, broadleaf weed that can be found just about anywhere. However, it prefers nutrient rich-soils that are moist and often high in calcium (clay soils are typically high in calcium). Broadleaf plan-tain is a common weed in lawns and landscapes as it can tolerate very low mow-ing heights. It germinates from seed in late spring through the fall depending on temperature and moisture. It has a low growing rosette habit and tolerates close mowing.
It is easily identified by the basal rosette growth habit, but if in doubt, pull up a plant and check to verify that it has a fibrous root system (as opposed to a taproot) and has broad, flat leaves with parallel venation. Leaf margins are “entire” meaning no scalloped or serrated edges. This time of year the plant can also be identified by the long leafless flower stalks standing high above the rest of the plant. The flowers don’t look like flowers at all – they just look weird.
Young plantain leaves are edible as a salad green in the spring. The seeds are considered high in protein. The crushed leaves are also said to eliminate the itch of mosquito bites within sec-onds. However, since my patch is right next to the road in soil of questionable quality (thanks to the aforementioned sewer repair), I think I won’t be eating it any time soon. If you are consider-ing this as a garden edible, there are plenty of sites online selling seed and bare-root plants. OR, you can come dig some up from my tree lawn. Take all you want!
Common Mallow (Malva neglecta) August 2021
In preparing for an Edible Weed program I am giving to a local garden club in August, I pulled out my “Edible Wild Plants” book for a review. Somehow in my previous study, I had missed Mallow. Common mallow, Malva neglecta, is a weed that is well known to me as I pull quite a bit of it. What I did not realize is that you can make marshmallow (also meringue) from mallow. OK, that seems obvious. Not so obvious is that the sticky, gooey, starchy part of the plant is the seed pods which resemble small cheese rounds (think Babybel cheese). The seed pods remind me of ground cherries.
Common mallow is an annual that grows low to the ground. It has a small taproot but is easily hand-pulled. The flowers range in color from white with purple stripes to deep lavender with pur-ple stripes. While the plant grows in virtually every US state, I have never found it invasive – at least not in my yard.
If you aren’t particularly fond of marshmallow or meringue, the young leaves can be used as a salad green while older leaves can be made into tea.
Sorry – I just compost mine.
Pokeweed (Phytolacca americana) July 2021
Tall with lovely purplish-red stems, large showy leaves and grape-cluster-like deep purple berries appearing after a pretty spray of white flowers. It can grow 6 – 10 feet tall and support small birds. What’s not to love? Pulling it out by the wheelbarrow full! That’s what!
This month’s weed is Pokeweed, also known as Pokeberry, (Phytolacca americana) is a perennial native plant that grows…well, almost anywhere! The plant is hazardous to livestock and all parts of the plant are considered toxic. The berries are particularly poisonous to humans so if you have pokeweed and small children that play in the area, be sure to keep the 2 apart! Some people consider pokeweed edible and eat poke salad in the spring after boiling the leaves, but I definitely don’t recommend it; the risk is too high.
Eradicating pokeweed is as easy as pulling it out, provided the soil is soft. For an older perennial plant with a larger root, digging may be required. The stems of pokeweed are hollow so control may be gained by cutting off the plant and pouring vinegar, salt, baking soda or weed killer into the hollow stem. As a temporary measure to reduce the spread, simply cut the flowers off before it goes to seed. Birds love the seeds and spread them liberally. Seed is viable in the soil for 40 years so this is another reason to cut off the blossoms before the seeds are produced. Wear old clothes and gardening gloves when handling pokeweed; some people are sensitive to toxins in the foliage. And, if the berries are present, you will end up with purple hands and purple-polka dotted clothing.
Carpetweed (Mollugo verticillate) June 2021
About 15 years ago, when I was first doing my deep-dive study of weeds, I went to a program where I was introduced to this very pretty and unusual weed called carpetweed. I was very intrigued and decided to bring home a plant to study it more closely. After analyzing the leaf structure, stems and roots, I tossed it into my compost pile. I have spent the last 15 years pulling it out of my beds. My neighbors give me the stink eye every time they are working in their yards as, they too, have spent the last 15 years pulling it. Sigh!
Carpetweed, Mollugo verticillate, is a prostrate annual that forms dense circular mats of foliage. In other words, it forms a thick, low-growing carpet. And, it grows FAST! It initially intrigued me because it is one of very few weeds with a “whorled” leaf structure. It is particularly invasive be-cause it flowers (inconspicuously) prolifically from late June – September and the flowers pro-duce round seeds that STICK TO EVERYTHING! I can tell you that the seeds are virtually im-possible to pick off clothing. They don’t even come off in the washing machine. Therefore, the seeds are easily transported by animals and hu-mans to other locations.
Carpetweed is a particular nuisance in cultivated areas such as farm fields, garden beds or newly seeded lawns. It is commonly confused with Catchweed Bedstraw (Calium aparine). Catch-weed bedstraw has a square stem while carpet-weed stems are round. The only good thing to be said for carpetweed is that it is easily pulled by hand. Which is a good thing because if you have it in your yard, you will be pulling lots of it.
