There is a weed that grows seed pods that look like little Chinese lanterns. It is commonly called ground cherry, but it is also known by everything from Mexican husk tomato to gooseberry. The Golden Guide titled Weeds says there are about 80 species under it’s Latin genus of Physalis, but the Handbook of Poisonous and Injurious Plants (HPIP) says only 17 of these grow in the United States. HPIP also lists 25 different common names for this weed.
The little lanterns might be cute if it weren’t for other characteristics of this weed:
The roots grow deep networks
The stem breaks easily at the root
The leaves and unripe berries are toxic
The toxicity is the same as caused by potatoes, due to solanine glycoalkaloids. The symptoms are gastrointestinal and neurological, with the severity of them depending on the dose. This University of California, Davis Review of Important Facts about Potato Glycoalkaloids succinctly covers the important details. In summary from this site and HPIP, the effects are:
- abdominal pain
While my chickens have safely foraged in a pen with a few ground cherries (the plants soon died from the constant scratching), I would be careful about letting animals like goats or horses around them. I am also going to be careful with disposing of them while my lab puppy is around, as she likes to chew on many things I pull from the garden. However, some people do harvest the fruits (completely ripe) and think they taste yummy.
Unlike some weeds, ground cherry is not all that bad to look at. There are some species in the genus that are grown for ornamentals and to harvest the ripe berries. Wild animals also eat them. The photo below is from the Missouri State weed page. They have an extensive library of weed photos there.
The plant’s presence above ground begins with a single stem that grows straight up for a couple of inches, topped by a tight bunch of leaves. This floret of leaves soon opens up, and not long after the plant forms branches that remind me of pepper plants. It is about the same height, too, typically being 1 – 3 feet high at maturity.
The variety of ground cherry that grows in my yard has shiny, smooth edge, eliptical shaped, deep green leaves. According to some resources, some plants have fuzzier leaves with some being more pointed and some more rounded.
As soon as the plants get to full size, they are quick to flower. The flowers are bell shaped, usually yellow with some dark spots in the center.
It doesn’t take much longer for the lantern seed pods to form, then dry, and drop all over the ground. Once they are dry, the lanterns break open quite easily, spreading seeds willy-nilly.
As I show in my video, digging the plants out can be frustrating. Not only do the stems or upper root sections break easily, but there are strong lateral roots under the ground that remain to sprout again. This Oregon State University extension drawing also shows these robust and evasive lateral roots. These roots seem to be perennial, as the plants tend to come back in the exact same spot year after year.
I have been able to successfully grow grass over a bare patch that once regularly sprouted an abundance of ground cherry. The grass is treated regularly to control broadleaf weeds. In other places, regular chicken scratching has eradicated the plants.
I have used weed killer, specifically Round-Up, on ground cherry in my vegetable and flower beds with limited results. It seems to knock the plant back mildly, but it keeps growing and rejuvenates quickly. It is hard to cut it back regularly enough to deplete the vitality of the roots, but if you have a small garden and a small patch, that helps some. As this summary of eradication strategies discusses, even the ornamental ground cherry varieties are considered highly invasive.
Basically, this is not a weed that you want to let grow at all. It is not just a matter of pulling up the plants at your convenience. Once it gets a foothold, there will an ongoing battle.