Tuesday, March 29, 2011

First spring manoeuvre in the war on slugs - building a raised bed

*see below
Dear readers, Sorry for my long absence. I don't know how some of you garden bloggers manage to produce such frequent and wonderful posts. And I know all of you are just as busy as I am in the spring. Please bear with me!

On to today's topic: I've already reported on my struggle with slugs in a post listing my experiences with plants they eat / do not eat, and in a post reporting on some literature I bought and read on the subject.

So this year, acting on the belief that, based on relative size of brain, I should be able to outwit these creatures without having to slaughter or poison them, I've decided to go all out and launch a strategic multiple offensive. Although my son encouragingly pointed out that they probably outnumber me at a ratio significantly more lopsided than that of our relative brain size, I refused to be daunted and have now completed my first tactical move: installing a raised bed with a slug barrier around it.

For various reasons - not the least being that we don't have electricity for power tools in the garden - I decided to purchase a raised bed kit from the Berlin-based Hogart company rather than build one from scratch. I'm providing the link for any interested readers in Germany because I'm very satisfied with their product and service and can highly recommend the L2 model raised bed we bought.

The raised bed is constructed of larch native to central Europe, a hardy wood resistant to rot. The kit included 6 pre-assembled side walls for a bed measuring approx. 200 cm x 100cm x 80cm; posts, screws and pre-marked drill holes; wire mesh for the floor to prevent voles, rats and moles from making their home in the bed; and heavy-duty plastic lining to protect the wood and help keep the bed moist. It also came with excellent thorough instructions.

raised bed and snail barrier parts
To assemble the bed, 120 screws were needed to connect the side walls to the posts. My husband got into this manly garden hardware task, which was also a good excuse to purchase a new battery-powered drill. Here's a shot of the almost finished bed.

The next task was to prepare a place for it on the lawn. Most advice says to place raised beds in a north-south orientation with lots of sun and easy access from all sides. I also wanted it near a water source, since raised beds need frequent watering. Once the location was chosen, we removed the sod and dug holes to sink the posts into.

After settling the bed into its final position, I painted the outside with organic, non-toxic oil to help maintain its beautiful warm reddish wood tone.

The next steps were to staple on the wire meshing and the lining.

The next task took longer than I thought - filling the bed. Two cubic meters is a LOT of space. We filled about half the space with branches, logs and twigs. After that came finer garden trimmings of all kinds, followed by the sod we had removed, grass side down. Fortunately, our garden colony's giant community compost heap is not far from our allotment, and I was able to fill a few wheelbarrows with branches there.

On top of the sod we emptied the entire contents of one of our bins of half-finished compost, and on top of that three sacks of organic compost I purchased from the city recycling center. I didn't want to use up all my own compost! The final layer was several sacks of purchased garden earth, and the bed was finally ready to plant.

For the first year, books and websites advise planting vegetables and flowers that need lots of nutrients, since raised beds are basically nutrient-rich compost heaps. I found somewhat conflicting lists on which plants these are, and ended up choosing bell peppers, leeks, kohlrabi, white radishes and red beets. The bell peppers and kohlrabi I had already propagated at home; all other seeds I planted directly into the bed. Raised beds can support more plants per square meter than normal garden earth due to their warmth - up to 8 degrees warmer than garden earth because of the fermenting going on below - and their nutrients. Because of the warmth I assumed it was alright to begin in late March, but at night I'm still covering the bed with fleece just in case.

Although a raised bed reportedly discourages slugs, I don't really believe it and decided to place a snail fence around the perimeter. I purchased the snail barrier from the company Metalltechnik Dermbach, and am also very satisfied with it, so much so that I've already purchased two more. Two square meters cost me about 40 Euros. Since this photo was taken we've sunk the fence about 10 cm into the ground, installed the corner pieces and screwed everything firmly to the raised bed.

Before putting up the fence around the raised bed, I tested a smaller 1 square meter version in one of the most slug-infested parts of the garden. I figured the ultimate test would be violas and zinnias, since these two flowers were devoured to the ground last year in this area. After almost a week they still haven't been touched.

Granted, it's been a dry spring so far, but I know that the principle these snail fences work on is effective, because last year I used snail collars that work the same way. They just cannot overcome the sharp angle. I watched a slug try unsuccessfully to surmount the snail collar on one of my sunflowers last year. Here are some of the collars protecting my sorrel.

While we were working this curious little guy watched from above!

That's all for today - happy gardening.

*Slug image at top of post courtesy of www.getridofslugs.com. I am not endorsing their book, because I'm not familiar with it, but figured they wouldn't object to me using the image if I provided the link.


  1. i like your non toxic war on slugs, i am going to look for snail collars over here so i can try them.

    Well mabe the other gardeners dont have such a huge garden to maintain :) Our garden is quite large for average dutch row houses. But compared to the rest of the world, and especcially the world of garden bloggers, we have a tiny garden.
    I also don't mind (read i really like) a sloppy wild looking flower garden :) (neighbours who pave their whole garden think my garden is slobby, but every day i see something different, and their paved garden always looks the same, expensive but boooring :) ) and my vegetable garden is only 1 square metre LOL

    I respect your nice and well maintained garden :)

  2. Liebe Barbara! Wir werden heuer auch ein Hochbeet bauen, das Holz dafür ist schon gekauft. Einen Schneckenzaun nennen wir auch unser eigen und er hilft gar nicht einmal so schlecht, allerdings alle Biester kann man damit auch nicht fernhalten - leider.

    lg kathrin

  3. Babara, your garden is very neat and tidy. The finished job looks like a planter box. The slugs won't be able to climb in but be careful of foreign soil. I hate the slugs too, so I make friends with the wildlife in my garden, especially the slug predators such as the birds, frogs and toads. So my garden become a war zone for pests and predators and prey!

  4. "... don't know how some of you garden bloggers manage to produce such frequent and wonderful posts", and on that I am with you. Seeds, seedlings, watering, fertilizing, still cutting back some of the garden... lol, but oh, the joy.

    Hi, Barbara, and so happy to "see" you. That raised bed looks delightful! I have some sad news: raised beds do not deter slugs; take it from one who has about 10 of them. The good news is that I think your clever collar around the bed is going to be great.

  5. You have been a busy little bee, what a great project. Hope the multitude leave you in peace this year.

  6. Fabulous idea. From what I see of your garden , it is huge and very organized! More pics, please!

  7. Good to see your have found time to blog again, Barbara! Oh, to be busy like you. Instead, as I type this, it is snowing again. This winter never ends! At least I can read of your garden adventures. Good luck with the new raised bed. Imagine working in it and not having to get down on the ground. How convenient! :-D

  8. Dear Barbara, you are one busy gardener! That is a HUGE raised bed! It looks solidly built so should last a long, long time. I don't have your slug problem (I have slugs, but nothing I can't manage)...but I do have other critter problems like moles, voles & squirrels,,,and also deer. Those beds would be perfect to keep out the little critters! (Of course, the deer would just stand at it and eat as if they were at a buffet table)! I hope it works out for you as you've planned. The weather here is rainy and cold...in the 30's right now, at night. In the days it's been in the 40's and sometimes 50's. Two weeks ago it was in the high 70's for days and we thought we were in heaven. Now, we can't wait for that weather to return!
    I'm guessing your soil is fairly damp during the summer for you to have such an extreme slug problem. I remember when we lived in Heidelberg, it was in the valley, and always overcast & cloudy. It rained a LOT, too. My husband worked in Mannheim and so did I (for about a year) but I can't remember if it was the same or just a bit drier? At any rate, I wish you great success growing lots of veggies with your amazing raised beds!

  9. Thanks for all your comments, which I always appreciate.
    Jan: Our garden is in the probably wettest area of the entire Mannheim-Heidelberg area - it's right on the border of the Rhine flood plains. Our slug problem is colossal. There are also deer, but up till now the high fence around the perimeter of the garden colony seems to be keeping them out. I also thought about how they could easily dine from the raised bed!
    Kris: It is divine not having to bend down. I've found that it's not so much my back that bothers me, it's my knees. I see more raised beds in my future.
    Rosey: I'm clever about taking shots that make the garden look organized I guess, because there are corners which definitely are not.
    Deborah: I will report on success/no success.
    Di: You have 10 raised beds! I am jealous. You have confirmed my suspicion that a raised bed alone will not deter slugs.
    Autumn Belle: natural predators would be the best slug solution, and we do have some toads and plenty of birds.
    Kathrin: I'd love to see a report on the raised bed you build.
    Hare majesteit: I'm with you - every garden needs some "messy" corners where things just grow wild. Definitely more interesting than neatly mowed lawns and tended borders.

  10. Hope it works for you and that there were no slug eggs in the material you put into the raised beds?

    We use vaseline round the tops or bases of planters which seems to work at stopping the slugs.

  11. Slugs are such a pest in a German Gartenplatz! As were the moles to my radish! That is some planter to deter the pests and the slug deterrent interesting. Good job constructing it and good luck with keeping pests at bay!

  12. What a big project! I love that your raised bed won't require stooping over though, that's going to be wonderful to garden in. Very smart use of the logs, twigs and sod too. It gets expensive filling raised beds, and when they're that deep, most plants will never reach the bottom anyway. Love the snail fence too. Although it looks like something I might accidentally catch my shin on. I have used a sticky copper tape along the tops of raised beds before. I didn't believe the slugs wouldn't cross it, but wanted to try, and it actually seemed to work. They really don't like copper. Looking forward to see your raised bed planted out!

  13. Well, if the slug hordes manage to surmount your setup, a duck might be in order. I've heard they are one of the only things that will eat slugs.

    I can never manage to post as often as I think I should and am amazed at how prolific some bloggers are. I can barely manage once a week!

    Christine in Alaska, no slugs...yet

  14. i want to make a beer trap for slugs, but i think its too yucky to empty the beer traps with all those slugs. i now have copper tape around the potted plants against slugs

  15. PS Come over and leave a comment on my sustainable living post for a chance to win 19 garden gifts...no need to write a blog post unless you want the composter or rainbarrel. The other 19 are pretty darn cool and require just a comment;-)

  16. Wow, this is an impressive slug defense. 2 cubic meters is indeed a lot of space! My wheelbarrow holds 6 cubic feet (less than 1/4 cubic meter), and I know how much hard work is involved in filling and/or emptying it. How clever of you to fill the bottom with big branches, etc. All the work will be so worth it when you, rather than the slugs, get to eat all those yummy vegetables. -Jean

  17. I'm staggered. I've never seen such a thing! (I even scrolled back to check the date, wondering if it might be an April Fool post.)

    It's massive - but why won't the slugs climb up? Snails climb over walls. Slugs climb an awful lot of things . . .

    Will it really work?

    Will the trapped soil survive?

    What a drama!

    What a box!