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.