By Cindy Watter, UC Master Gardener of Napa County
Snails and slugs never gave me trouble when I lived in the country because my hippie neighbors had a dozen ravenous geese that used to waddle over and gobble up the slimy little morsels. However, after I left that house and moved into town, I spent my tenth wedding anniversary date night plucking hundreds of the creatures off twelve dozen King Alfred daffodils and dropping them into a bucket of beer. Everyone told me that was the non-toxic way to do it. No one told me not to dump them in the compost pile, however. Lesson learned.)
Early spring is the time of year when snails and slugs appear. They love to chew on tender young foliage. If your garden suddenly displays leaves with holes and ragged edges, chances are you have slugs and/or snails. They hide in the cool damp areas of your yard and come out at night to do their work.
A patch of ivy or weeds or a collection of overturned flowerpots is a perfect habitat for them. You should leave a few leaf piles in your yard to promote biodiversity, but some tidying up can fix your problem. You can also capture them by propping a board on cleats to create a nesting place for them to hide in. Then you drop them in a jar of soapy water.
Or you could sprinkle finely ground diatomaceous earth around the roots of your plant or encircle plants or raised beds with copper strips. The diatomaceous-earth granules are uncomfortable to snails and they just don't like crossing copper at all.
You may also put out jar lids at night filled with beer to drown them. Don't use salt; it will hurt your plants. Make sure you have a space between the trunk of the plant and mulch, to make it harder for the snails to hide. If you must use commercial bait, find one made with iron phosphate. Baits containing metaldehyde are dangerous to pets and children.
Slugs and snails are gastropods, invertebrates that are part of the mollusk family. They have a round mouth, called a radula, with hundreds of tiny teeth that rasp and tear soft young leaves.
These creatures also act as nature's scavengers, removing all sorts of debris from forest and field. They have a purpose, but you don't want them destroying your plants.
The only real difference between a slug and a snail is the shell. Management is the same for both.
The brown garden snail (Cornu aspersa) is not native to North America. It comes from Europe and was brought here by well-meaning people who thought that escargots would become a popular food item. Alas, the snails escaped and became garden nuisances. Gourmets consider them a delicacy, and snails do appear on menus in the Napa Valley. However, most people think of these creatures as pests.
They look festive when they come out after a rain, and I should harden my heart and squash them then and there, but I don't. I keep hoping the birds will eat them.
Years ago, when there was a chemical solution for every problem, I stormed down to my garden store with murder in my heart. Snails had eaten my strawberries. I saw a box with an arresting brand name, promising “SLUG AND SNAIL DEATH.”
The package had a terrifying illustration that looked like a stone lithograph, printed on yellow cardboard. It featured three creatures—two slugs in the background and a snail in the foreground—with horns rampant, and the snail had an aggressive-looking frill on its front. These horrific invaders were so large they held their own against the background, a post-apocalyptic vermilion sun. I grabbed the box. Salvation was at hand.
And then I read the label in the lower left corner. (You should always do this, by the way.) It said: "Keep out of reach of children. CAUTION: This pesticide may be fatal to dogs or other pets if eaten. Keep pets out of treated area." So I went back to hand picking, because I had small children then.
The poison was metaldehyde. I have used iron phosphate bait but, unfortunately, my dog finds it attractive. (It smells like dried blood.) It doesn't hurt her, but it unnerves me. I will try diatomaceous earth.
I also have plenty of plants snails won't eat. Geranium, rosemary, lavender, California poppy and fuchsia don't attract them. Basil does, however.
I was discussing my pest-control quandary with an old friend, who told me I would no longer want to kill snails after I read The Sound of a Wild Snail Eating by Elizabeth Tova Bailey. I am sure that is true. Reading this book will make me feel better about the holes in my brugmansia leaves.
Find UC IPM Pest Note for Snails and Slugs here:
http://ipm.ucanr.edu/PMG/PESTNOTES/pn7427.html
Find UC IPM Quick Tips for Snails and Slugs here:
http://ipm.ucanr.edu/QT/snailsslugscard.html
Food Growing Forum: Second Sunday of the month through November. Sunday, March 14, 3 pm to 4 pm: “Fertilizers and Soil Health.” Register to get Zoom link: https://bit.ly/3r5bgwi
Workshop: UC Master Gardeners will lead a workshop on “Growing Tasty Tomatoes” on Saturday, March 27, from 10 a.m. to noon.” Register to get Zoom link:
Napa Library Talks: First Thursday of each month. Thursday, April 1: “Gardening on a Shoestring.” Register to get Zoom link: https://bit.ly/3rn3MF3
Got Garden Questions? Contact our Help Desk. The team is working remotely so please submit your questions through our diagnosis form, sending any photos to mastergardeners@countyofnapa.org or leave a detailed message at 707- 253-4143. A Master Gardener will get back to you by phone or email.
For more information visit http://napamg.ucanr.edu or find us on Facebook or Instagram, UC Master Gardeners of Napa County.
By Iris Craig, U. C. Master Gardener of Napa County
When I asked a friend how her garden was doing, she told me that the day after she planted lettuce and basil, she found nothing but stumps. I told her that the likely culprits were snails, birds or rodents. Her response: “Okay, but what can I do about it?”
Some say that a French chef introduced brown snails to California during the Gold Rush. They may be tasty with garlic butter, but they are destructive garden pests. What's more, they're prolific. These hermaphrodites lay, on average, 80 eggs every six months. They move on their foot, munching on plants during the night and foggy days. When the sun is out they hide in debris or tight leaves. They leave irregular holes with smooth edges and silvery mucous trails on seedlings, leaves and flowers.
The least toxic way to vanquish snails is to hunt them at night with a flashlight. If you pluck them off plants every other night for six weeks, you can win the battle. I collect them in a lidded jar or can and bring them to friends with chickens. Snail favorites include basil, beans, cabbage, dahlias, delphinium, hosta, lettuce, marigolds and strawberries, so monitor those plants closely.
You can trap snails by burying a shallow tin can or jar lid at ground level and filling it with beer. The snails are attracted to the beer and drown. You can also trap them by laying down boards with a stone at one end as a riser. The snails will crawl underneath. Copper barriers can help as snails don't like to crawl over them, but the copper deteriorates and needs replacing often. I have also had some success with string that emits a small charge. Egg shells and coffee grounds placed around plants can deter snails, especially in conjunction with other pest-management practices.
Before buying snail bait, do some research. Some formulations kill good creatures as well as snails and are potentially dangerous to small animals and plants. Iron phosphate baits such as Sluggo and Slug Magic are safer around children and small animals and can reduce snail populations.
Pesky birds in the Napa Valley include crowned sparrows, house finches, robins, scrub jay, crows, European starlings and yellow-billed magpies. They love ripe blueberries, tomatoes, grapes, strawberries, cherries and many other fruits. They also shred the edges of tender green leaves such as lettuce. Netting is the best deterrent. Drape the top of the tree or plant and secure the edges at ground level to prevent entry. Other methods include noisemakers, visual repellents, shooting, trapping and chemical repellents. All of these options help, but some may harm other animals.
Common rodents in the Napa Valley include roof rats, Norway rats, tree squirrels, ground squirrels, mice and bats. Roof rats and Norway rats are among the most troublesome garden pests in the United States. To control them, you need to know which species you are dealing with.
Sometimes called brown rats or sewer rats, Norway rats are stocky and larger than roof rats. They leave droppings and paper nests and they burrow under buildings and wood piles and in moist areas. Roof rats are climbers and nest in trees, tall shrubs and dense vegetation like ivy. You may also find them in attics and walls. Roof rats have a long tail, longer than their head and body combined. Unlike the Norway rat, they prefer an ocean climate and have a narrower range of habitat.
When you hear scurrying noises at night, grab a flashlight. Young roof rats can be mistaken for mice; however, their heads are larger in proportion to their bodies. Once you see evidence of rats outdoors, prepare to do battle or they will soon invade your home.
The easiest way to foil rats is to call an exterminator. Seal any openings in your home that are larger than one-quarter inch. Remove debris and place wire-mesh barricades around your garden if you have a large infestation. As a last resort, set spring traps. If necessary, use a poison that won't harm pets or children. Place it near pathways or wherever you see droppings.
My friend who asked me what was eating her plants saw a squirrel chomping on one. She now has a cage around her garden.
Workshop: Master Food Preservers will hold a workshop on “Food Preservation by Freezing & Drying” on Friday, July 27, from 10 a.m. to noon, at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Canning, freezing and drying are among the most basic food preserving methods. It is important to practice safe methods and to stay up-to-date with the most reliable information about food safety. Master Food Preservers will discuss each process, the equipment required and hazards to avoid, and give demonstrations and recipes. Online registration (credit card only); Mail-in/Walk-in registration (check only or drop off cash payment).
Workshop: Master Food Preservers will hold a workshop on “Pickling and Fermenting” on Saturday, July 28, from 10 a.m. to noon, at University of California Cooperative Extension, 1710 Soscol Avenue, Napa. Pickles are anything preserved by acidity. Vegetables that are fermented in the home kitchen create their own self-preserving, acidic liquid that is a by-product of the fermentation process. Led by Master Food Preservers, we will learn the basics of pickling and fermenting, understand the cautions involved in home food preservation, watch a demonstration of each process, and discuss recipes easily managed by the home cook.Online registration (credit card only); Mail-in/Walk-in registration (check only or drop off cash payment).
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.
When I was a child in Ireland, my mother was much given to reciting aphorisms--jewels of what might be called common sense. “Trifles make perfection, but perfection is no trifle” she would remind my siblings and me if we attempted to belittle her injunctions of tidiness and order.
It is surprising to me today how many of these counsels have remained in my recollections. One in particular, concerning the importance of patience, has had a lasting effect on my life:
Patience is a virtue
Catch if you can
Seldom in a woman
But never in a man.
The fact that this homily had a gender bias probably added to the attraction for my mother.
I am the very model of a patient gardener. I realized many years ago that you can’t rush things in your garden. A seed may take what seems like forever to germinate. Many fruit trees relax for three years or so before fulfilling their fruiting mission. Patience is also required when dealing with those slimy visitors that regard our carefully cultivated plants as a banquet.
I’ve had some moments of trauma on this front. On one occasion I purchased a flat of beautiful marigolds. I planted them in my garden, looked admiringly at them, smiled a well-pleased kind of smile and then retired to dream.
The next next morning, my first mission was to visit my baby marigolds: how had they fared on their first night? Had they survived the creatures moving around in the darkness?
Lighthearted and expecting a joyful scenario, I approached the marigold bed. Expectant joy turned to eye-popping horror. Gone. Vanished. Nary a petal to be seen. Was this some kind of horrifying chimera? Had thieves in the night come and abducted my neonates? Had some malicious being spirited them away?
I immediately identified with the image of a desolate Silas Marner when he discovered that his gold hoard had been stolen. His gold coins were as children to him. He loved them. Their disappearance was a devastating trauma. He put his trembling hands to his head, and gave a wild ringing scream, the cry of desolation.
I didn’t scream or cry but I allowed thoughts of vengeance to grow in my gardener’s heart. On the night after this shocking discovery, armed with a powerful flashlight, I patrolled my flower beds. The perpetrators were sashaying in extraordinary numbers all over my garden.
With violence in my heart I eliminated that night’s promenaders, dozens of them. Night after night, patiently and methodically, my process of decimation continued until I knew the most fragile of flowers would be safe in my garden, day or night. Since that time, it has been my practice to patrol my garden for a number of nights at the beginning of each planting season to ensure a snail-free environment for my vulnerable seedlings and buds. This effort requires a little patience, but patience is more effective than snail bait. I have not seen a snail in my garden for several years.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners (http://ucanr.org/ucmgnapa) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions?