Updated: Feb 13
Gardener's Trigger Alert: SLUGS!
Seriously, they cause great anxiety for my daughter and I can't talk about them here. Since posting pics of my urban farm, I am getting questions about slugs. As an all season greens producer, managing slugs has been an important process and while every property is different, there are a few things that I have learned over the last few years that I thought I'd share. Though slugs are admirable, they can make plants more succeptible to disease and can spread diseases from rats. FYI I do not use slug bait of any kind.
Only 2 years ago I was direct seeding lettuce to have it ALL disappear before developing true leaves. Coming out with a flashlight I noticed that it was slugs. I replanted 2 more times and the same thing happened. Of course I planted it in shady spot, because lettuce likes shade, right? Well, I do things very differently now.
1. The only thing I direct seed in spring are densely planted crops with a tap root: cilantro, carrots, dill etc. Otherwise I grow seedlings of varying sizes inside using Sunblaster LED prismatic lighting. I plant the largest seedlings in the shade. Lettuce actually can get leggy when seeded in the shade.
2. I stopped piling rotting logs (full of slug eggs) and wood into raised beds and I removed as many rasied beds as possible, keeping only those that are on compacted ground/paved areas or over tree stumps, preferring metal or cedar to other wood (because I also have a pill bug infestation). In my pine raised beds, the slug damage is much higher than where I am growing in the ground. Why? Because they hide in the nooks and crannies and the wood decomposes.
3. Harvest frequently to keep things open during wet spells and do it in the rain. For avoiding the spread of disease we are told not to touch plants when they are wet. If a plant is diseased, this is good advice and I do wash my hands after handling lettuce with shrivelled bottom leaves etc. or keep a spray bottle with hyrdrogen peroxide and water to disinfect occasionally. BUT I like to harvest in the rain because the slugs are on the plants and when I remove the outer leaves and wash them, I am removing slugs.
4. Understand their preferred crops. Don't grow only buttercrunch and iceberg lettuce in spring and summer because you like the mild flavours if you have a lot of slugs. Because they like it too! Though red lettuce tends to get bitter in the heat I love it partly because the slugs don't (and bitter is healthy). My red lettuce has NO holes. Endive is almost untouched and chard is mostly plagued by leaf miner. However, if I only grew red lettuce and endive, they may be full of holes. This time of year, when slugs start to get active, I plant trap crops and cook or compost them: choho and certain types of lettuce.
5. Use copper mesh burried around the base of the plant. This slows them down but does not totally prevent them and is time consuming/expensive so I only use the copper mesh to protect fruiting crops from rodents now.
Leave a board down or something and check it on rainy days and in the morning. Put the slugs in soapy water or skewer them and leave them out for the shrews and other critters. Check under pots etc.
6. Unless mice are a real problem, don't keep the shrews out of your growing area with 1/4 inch mesh. Use 1/2 inch instead, which will keep rats, squirrels and other critters out but let in the shrews who devour slugs. I had shrews nesting in one of my winter beds and the leaves were free of holes (but the stench was something!)
7. Water in the morning and let the soil dry by evening. Slugs don't like to travel on dry ground.
8. Pick the tiny slugs in the spring even if they seam insignificant. They will grow by fall! Then focus on culling them in early fall.
I don't use slug bait, as they attract rodents and can be toxic. Plus I never found it to work.
9. Let your lettuce (and some other crops) bolt! Certain types of lettuce bolt magnificantly IF you keep feeding them: Grand Rapids, Tropicana, Merlot etc to name a few. Once they start bolting they become less palatable and also harder to reach for the slugs. And they become healthier for us.
10. Practice protected growing during the colder months! See these pics comparing 2 choho plants. One, pictured in April, is looking pristine, and the other, pictured in late May, is really eaten up. Cut back your overwintered kale and let it keep sending out tender leaves in spring. The slugs don't like these but they may love a young kale seedling.
11. Accept the holes. Wash and perhaps cook.
12. Grow slug prone crops on the balcony and in pots if possible (as pictured).
I do not mulch but plant closely to conserve water, harvesting more heavily to make space during wet peiods.
13. Research them so you can at least respect their gift at survival and the roles they play. This will help emotionally.
I am not a therapist, but I am here if you need to vent.