Writing about the possible benefits of invasive plants, I had the fear that for most broad-leafed weeds it would be easy to find medicinal and other value, but that for grasses, I might have to pass. Interestingly, grasses have some good sides, too – even a such-maligned, horrible weed as crab grass.
Crab grass (also called “finger grass” because of its spiky inflorescences, or “fonio”, for African plants) are actually several Digitaria species – “Digitaria” again meaning “finger-like”.
Why is crab grass the proverbial weed? It turns out that “crabs” can’t take hold in a well-watered, well-fertilized lawn. But let that lawn be neglected, and develop some bald spots – that’s where the annual crab grass will move in, taking advantage.
A lawn usually consists of perennial grasses that stay green long into fall and often into winter. Crab grass would be fine to be intermingled, if it would not die by the end of summer and will leave a bald spot – especially if you pull it and do not immediately reseed with normal lawn seed. In that bald spot, its many, many seeds can take hold again. Crab grass’ trick is its long germination period: It might die early, but it can germinate basically all year, as long as there is no snow on the ground. Usually, a bald crab grass spot extends thus from season to season, always looking awful in the fall, showing your neighbors that you are a less-than-perfect gardener.
Remedy? Keep your grass healthy, well-fed, well-watered, well-limed, and reseed in fall and spring, so that crab grass seedlings have no chance.
So, what for is this invasive grass good? For cows and other ungulates like deer crab grass is as nutritious as any other grass; even more so, because of its high protein contents. Sub-Saharan Africa people eat the milled crab grass seeds in porridge and bread. The problem with crab grass is that it germinates and ripens its seed willfully throughout the year. Therefore it must be hand-harvested, defying large-scale cultivation. However, early settlers in America purposefully would till a spot in the spring so that crab grass could grow there, for the grazing of the animals later in the year.
Crab grass (like Bermuda grass) is a warm-weather grass. As such, it accumulates less sugar than a perennial grass - it does not intend to stay around for the winter, needing staying power through the winter. That makes crab grass better digestible especially to horses who might be quite sensitive to a high sugar and starch content – which bloats them, causing colic. So, as hay, crab grass is quite desirable.
Crab grass contains non-trivial amounts of magnesium, phosphorus and calcium – important for bone health, and some vitamin A, folate, and retinol; they might account for its use in eye health: Medicinally, crabgrass infusion is said to be helping against cataracts and feebleness. I probably won’t use it exactly for that purpose. But just knowing that crab grass is not poisonous will land it in my garden teas from now on. Read More
Blog: On Health. On Writing. On Life. On Everything.
Invasive Plants 2: List
October 11, 2011
My home state publishes a list on invasive species for Massachusetts, and also defines which criteria a plant has to meet to be labeled “invasive”:
1. It is not native to Massachusetts
2. Must have the “biologic potential for rapid and widespread dispersion and establishment”
3. Must have the “biologic potential for dispersing over spatial gaps away from the site of introduction”
4. Must have the “biologic potential for existing in high numbers” away from gardens
5. Must have been introduced to Massachusetts already
The real text is a bit more cumbersome and bureaucratic – but we get the idea. There are tons of species on the lists, but here are a few from the list I would add to my list (this is arbitrary and based on my very personal experiences as a gardener at a single spot in Massachusetts – you might have a different opinion; it is worthwhile finding the list of invasive plants for your state!):
1. Japanese barberry – it stayed a single beautiful bush in my garden. But of course I can’t know to which places birds dispersed its seeds
2. Bittersweet. There are two bittersweets, with orange berries. One Celastrus scandens, the "American bittersweet" is non-invasive. The Asian or Oriental bittersweet is Celastrus orbiculatus, highly invasive. And it is the plant I called euonymus which I was familiar with from Europe. It seems, celastrus and euonymus are related species, and it is really the Celastrus orbiculatus that is so overly invasive. This vine’s berries are spread by birds, and the plant can strangle even trees. One of the worst I know – I would not plant it, and I am hacking it down wherever I meet it.
3. Purple loosestrife: Years ago, I bought a “butterfly bush” by mail order. It turned out to be purple loosestrife. As much as I try to eradicate it, it comes always up somewhere.
4. Wild rose (Rosa multiflora) is pretty while in bloom. But it flowers only once, and after flowering I always cut it of so it doesn’t set seeds. The rootstock, however – I’ll never get it out of my garden again.
5. Privet (Ligustrum vulgare) – it was in my garden when I moved in. It also might be another species as they are notoriously hard to identify. As often as I cut it back, it always pops up again.
6. Pennisetum, a vertically striped grass. Beautiful white and green. It is not invasive according to the Massachusetts definition, but like wisteria, it wants to take over my garden. There is a horizontally striped grass (Miscanthus sinensis) that might also become invasive – luckily, I never planted it.
7. White mulberry (Morus alba). Twice I planted a mulberry tree in my garden – mail orders. Twice they were not what they were advertised at: black mulberries. I wanted one in my garden desperately so that for once we can harvest our cherries before the birds do. Twice I had to hack down the tree because it grew as fast as Jack’s beanstalk – and did not deliver.
Now, our alphabetical list looks like this:
1. Bamboo (more than 70 genera in the Poaceae family)
2. Bermuda grass (Cynodon dactylon, also: Panicum dactylon, Capriola dactylon)
3. Bindweed (many species from the Convolvulus or Calystegia families)
4. Bittersweet (Celastrus orbiculatus)
5. Blackberries (Rubus spp.)
6. Burdock (Arctium lappa, and other species of Arctium)
7. Canada thistle (Cirsium arvense)
8. Chickweed (Stellaria spp.)
9. Crab grass (Digitaria spp. )
10. Dandelion (Taraxum officinale)
11. Ground ivy (Glechoma hederacea, also: Nepeta glechoma, Nepeta hederacea)
12. Japanese barberry (Berberis thunbergii)
13. Johnson grass (Sorghum halepense)
14. Kudzu (Pueraria lobata)
15. Miscanthus (Miscanthus sinensis)
16. Nightshade vine, bittersweet nightshade (Solanum dulcamara)
17. Pachysandra (Pachysandra terminalis)
18. Pennisetum (Pennisetum spp.)
19. Pokeweed (Phytolacca americana)
20. Privet (Ligustrum vulgare).
21. Purple loosestrife (Lythrum salicaria)
22. Purslane (Portulaca oleracea)
23. Quackgrass, also: couch grass (Elytrigia repens, also: Triticum repens, Agropyron repens, Elymus repens)
24. Raspberries (Rubus spp. – like the blackberries)
25. White mulberry (Morus alba)
26. Wild rose (Rosa multiflora)
27. Wild wine (Vitis labrusca)
28. Wisteria (Japanese: Wisteria floribunda; Chinese: Wisteria sinensis)
29. Wormwood (Artemisia absynthium)
Sorry, compiling all this, takes longer than thought. In the next installment, we will hopefully discover the medicinal value of some of these invasive plants – the idea being, if we harvest and eat them, they will be less invasive. Read More
The 10 Worst Garden Weeds – Really?
October 10, 2011
According to a survey of the “Mother Earth News” (“The original guide to living wisely”) the following are the ten weeds that make life for the nation’s vegetable gardeners miserable:
1. Crab grass
2. Dandelion
3. Bermuda grass
4. Bindweed
5. Chickweed
6. Ground ivy
7. Canada thistle
8. Burdock
9. Quackgrass
10. Johnson grass
Add to these another ten plants that I wish I had never planted in my own Massachusetts garden – or that arrived on their own out of nowhere:
1. Wisteria
2. Wild wine
3. Raspberries
4. Blackberries
5. Wormwood
6. Pachysandra
7. Euonymus
8. Deadly nightshade
9. Purslane
10. Pokeweed
I wonder why kudzu isn’t mentioned – we hear that is stealthily covers all of the South, a mile a minute. Why is kudzu not mentioned?? And bamboo??
Let’s sort them alphabetically:
1. Bamboo
2. Bermuda grass
3. Bindweed
4. Blackberries
5. Burdock
6. Canada thistle
7. Chickweed
8. Crab grass
9. Dandelion
10. Deadly nightshade
11. Euonymus
12. Ground ivy
13. Johnson grass
14. Kudzu
15. Pachysandra
16. Pokeweed
17. Purslane
18. Quackgrass
19. Raspberries
20. Wild wine
21. Wisteria
22. Wormwood
But – stop right here! Putting up lists of invasive plants and policing them – that’s not good gardening and not good stewardship of the Earth. Let’s assume for a moment that these plants all serve a purpose – or as Sebastian Kneipp put it: “God lets an herb grow for every ailment we complain about.”
Tomorrow, I will go through the list and try to divine the purpose behind each plant. Read More