Foraging for escargots

I grow many of my own vegetables, but find it harder to get protein. I have corresponded with someone in Washington State who raises escargots, and he mentioned Cornu aspersum was edible, easy to raise, AND invasive. I’ve noticed that there seem to be more snails than slugs as our climate changes.

I would love to volunteer at UW Botanic Gardens and help reduce the snail population. I was on a recent walk and was told that some of the dedicated gardeners come at night with flashlights to find snails, and I would be happy to assist.

Our manager of horticulture says that slug/snail baits are occasionally used as control methods, but there is no such practice as gardeners going out after hours with flashlights seeking slugs and snails in the Arboretum. Your observation about the increasing snail population, and the role of climate change seems to be substantiated. Here is an excerpt from an article in the Everett Herald, which quotes local malacologist David George Gordon: “‘Snails can endure droughts better than slugs because they can pull back into their shells,’ Gordon said. The general warming of the climate, with milder winters, also means there are fewer mass killings during cold snaps.”

The concern when foraging for anything, including invasive snails, is that what you harvest may contain toxic substances. If you want to collect snails, you can try to gather them only from your own garden or a garden you know does not use metaldehyde or iron phosphate-based bait, but even then, they may have been in a landscape nearby and consumed who knows what, including slug bait and poisonous plants.

The USDA APHIS (Animal and Plant Health Inspection Service) has guidelines about quarantine of Cornu aspersum and other non-native mollusk species. This includes not breeding them, and not using them in classrooms or nature facilities. Those who want to cultivate escargots have a different perspective. Perhaps Ric Brewer, the article’s author, is the Washington snail farmer you mention. He doesn’t address concerns about snails in an urban setting, and what they may have consumed beyond the borders of one person’s small city garden, which is not a closed system.

A safer and more ecologically sound way to introduce protein sources into your garden would be to grow sunflowers for their seeds, and if you have space, a couple of nut-bearing trees.

Food safety, Invasive species, Snails

arrival of the brown marmorated stink bug in the PNW

I’ve been hearing lately that there’s a new invasive insect called brown marmorated stink bug.

What plants does it damage, and how can I prevent or control the damage?

Yes, the brown marmorated stink bug is a recent arrival in the Pacific Northwest. Washington State University Extension has a Pest Watch fact sheet that provides details on its life cycle, contrast with similar-looking bugs in our area, and potential damage the bug causes. “BMSB,” as it is called, is well-known on the East Coast for damaging agricultural/edible crops and ornamental plants, as well as seeking refuge inside houses during cold weather (they don’t harm people, but they do emit offensive odors).

The website “Stop Brown Marmorated Stink Bug” is the main information clearinghouse on controlling this pest.It includes a list of host plants (two of the most attractive to BMSB are invasives themselves: Ailanthus altissima or Tree of Heaven, and Paulownia tomentosa or Empress Tree). Washington State University is involved in research on natural predators and control methods for this invader (as well as another recent one, Spotted Wing Drosophila). Most chemical interventions attempted so far have had limited efficacy. Research into organic controls is ongoing.

For now, get to know what the bug looks like, and if you think you see one in your garden or home, report it as a citizen-scientist using the form on the website of Stinkbug-Info.org or contact your local WSU Extension office.

So far, the only officially reported sightings in Washington State have been in Clark and Skamania counties.

Ladybugs: benefits and drawbacks

Ladybugs: are they beneficial? Invasive? I know that nurseries sell them for release into the garden. Is that a good idea?

The type of ladybug most often for sale is an introduced species. This factsheet from Linda Chalker-Scott of Washington State University provides a thorough explanation of why it is problematic.

Multicolored Asian lady beetles are generalist predators and they can be beneficial in the garden, but they also displace the North American native species of lady beetle. Purchasing them is not recommended and is probably a waste of money because, well, they have wings, and they will fly away. Former University of Washington Botanic Gardens director Sarah Reichard’s book, The Conscientious Gardener, advises that you instead avoid using insecticides so that your landscape will naturally attract beneficial insects, particularly native ones.

Another drawback of releasing ladybug larvae in your garden is that they sometimes find their way indoors, where you don’t want them to be. The multicolored Asian lady beetles (Harmonia axyridis) look for crevices to spend the winter hibernating and they seem particularly fond of light colored south walls. If you don’t want to find thousands of these beneficial insects flying around your house on the first sunny day in spring, fill the cracks in your house siding with caulk. For a description, management ideas, and detailed vacuum cleaner bagging instructions, Ohio State University Extension has a fact sheet on these insects. Inside a home, the insect droppings are a human health hazard, and can trigger asthma and other allergic reactions.

vermicomposting best practices

I have read about the problem with earthworms invading forests and overeating the duff, forest floor, disturbing the local biosystem, etc.

What about in our Puget Sound area? Is this a threat, and should we be concerned about worms escaping from worm bins and vermicomposting projects?

If you have a worm bin, be sure that the worms inhabiting it are red wiggler worms, Eisenia fetida (the kind which are ideal for vermicomposting), and never dispose of the contents of a worm bin in a wooded area.

According to former UW Botanic Gardens director Sarah Reichard’s book, The Conscientious Gardener (University of California Press, 2011), “where native worms already exist, new introductions […] may overconsume local food sources. But perhaps the most serious problems occur where there are no native worms, such as the northern temperate forests of North America […]. There, the worms modify the soil structure, affecting the flora and fauna.” Reichard recommends that gardeners not use soil with worms in it as fill dirt, and not dispose of nursery material with worms in it, especially in a wooded area. To be cautious, you can freeze your worm bin compost for one to four weeks to kill the worms. Be sure the supplier of your composting worms is knowledgeable about the species of worm they are selling. Reichard says: “…better yet, do not use worms at all: let naturally occurring organisms break down the waste.”

The invasive worm problem is a major issue in places like Minnesota. Here is information about that state’s attempt to prevent earthworm invasions of forest land. Note that they say Eisenia fetida (red wiggler) is safe because it will not survive winter temperatures. Our winters are not as cold, but I did not find any documentation to suggest that red wiggler worms are a problem in the Pacific Northwest.

Lady Bird Wildflower Center (in Texas) replied to a question similar to yours:

Excerpts:
“The bottom line is that in the far northern deciduous forests there is great concern over the presence of exotic species of earthworms because of their effect on the soils; while in the unglaciated southern regions, although there is some concern, the impact of the exotic species on soil processes is of minimal concern.
“The habitat and available food will define where exotic species can live. Eisenia fetida lives in surface soil and its food is leaf litter, microbes, and soil with high organic content. Hendrix and Bohlen (Hendrix, P. F. and P. J. Bohlen. 2002. Exotic Earthworm Invasions in North America: Ecological and Policy Implications. BioScience V. 52, no. 9, pp. 801-811) say: ‘Earthworms species from northern latitudes (e.g., European lumbricids and some Asian megascolecids) are poor colonizers in tropical or subtropical climates (except in localized temperate situations), and vice versa. For example, despite continued and widespread introduction throughout the United States, Eisenia fetida, the lumbricid “manure worm” commonly used in vermicomposting, is not often found in natural habitats in the southern United States.”

As far as I know, the only endangered native earthworm species in our state is the Giant Palouse Earthworm. Nevertheless, it’s prudent not to release your vermicomposting worms into the wild anywhere.

on Marimo or moss ball

I saw some moss balls for sale in the gift shop of the new Nordic Museum. What type of moss is used? Is it native to Nordic countries? How do I care for one indoors?

The “moss” is actually a type of freshwater alga, Aegagropila linnaei, found in only a small number of northern hemisphere lakes. Other common names are lake ball or Cladophora ball. In Japan, they are called marimo (meaning a bouncy ball that is in water). The Ainu people of Hokkaido hold an annual Marimo Festival at Lake Akan to celebrate these charming lake goblins.

Iceland’s Lake Mývatn once had the world’s largest colony of lake balls but pollution has been altering the ecosystem there, and the mats of algae balls (colloquially called round sh*t or muck balls by the fishing community) began dying out. Their disappearance was first noted in 2013. There are some recent signs that the nutrient imbalance of the lake (caused by fertilizer runoff, and accumulation of bacteria) is correcting itself and that the ecosystem of the lake is bouncing back to better health.

To grow marimo inside, you will need a container that holds water, and a spot where the algae receive indirect sunlight. They prefer cool locations in nature, so they will do best if they do not get too hot (don’t put them near a heat source, and if it gets hot in your home, you can cool them off in water in the refrigerator). To keep the balls floating, squeeze out some of the water from time to time. To propagate the algae, use scissors to divide the marimo in half after squeezing out some of the water (you can repeat this process and cut into fourths or eighths). Use thread to wrap the cut algae back into a rounded shape, tie the thread close to the ball, and put back into the water. Some people combine them with other plants and tiny shrimp in indoor aquascapes.

If you have just acquired your marimo, inspect it for signs of invasive zebra mussels, which sometimes hitch a ride on the moss balls in the import process. According to a 2024 report from the Washington Department of Fish and Wildlife, they have been found in marimo imported to a Renton aquarium supply wholesale business. If you need to dispose of a moss ball, keep it out of local waterways, and dispose of it safely, as follows: “If there is any sign of invasive mussels, do NOT dispose of them in drains, waterways, or gardens! Contaminated moss balls must destroyed (either by freezing, boiling, or bleaching), disposed of in a sealed plastic bag in the trash, and your aquarium must be drained and decontaminated.” Sightings should be reported here.

Algae, Aquatic plants, Indoor gardening, Invasive species

Invasive Species in the Pacific Northwest

Invasive species of the Pacific Northwest cover This collaboration of over 80 authors, most of them students at the University of Washington, is a field guide to the region’s invasive species that includes not only the noxious weeds gardeners fear, but aquatic plants, animals, invertebrates and even diseases. Sarah Reichard, head of conservation for UWBG, is one of the three editors that managed the project. The inclusion of the domestic cat is sure to get your attention, but a thorough reading describes a complex ecological web that will influence the way we look at the world around, especially in our gardens. The whole discussion of what constitutes an invasive species is fascinating in itself. A special section on these issues as they pertain to the Haida Gwaii is nice companion reading to the previous book.

Excerpted from the Fall 2007 Arboretum Bulletin.