Slug-resistant plants II: Love-in-a-Mist and Dame's Rocket

Both Love-in-a-Mist (Nigella damascena) and  Dame's Rocket (Hesperis matronalis) are flowers I tried after reading that they are usually left alone by slugs. Into my second summer with them I can confirm that this is true.

These flowers are touted as cottage garden favorites, and have been grown in European gardens for hundreds of years. That and the fact that they are native to Europe appealed to me. Love-in-a-Mist (in German: Jungfer im Grünen) is an annual, and Dame's Rocket (in German: Nachtviole) is usually called a biennial or short-lived perennial. In my garden, Dame's Rocket only survived one of our mild winters, but both plants have self-seeded very generously.

In fact, in the meantime I've learned that Dame's Rocket is regarded in some U.S. states as an invasive species, although in my experience, Love-in-a-Mist deserves this honor much more! I've been battling Love-in-a-Mist all spring, literally ripping out hundreds of offspring from the original 10 or so I planted from seed last year. Here it is crowding out some of my herbs. One place it didn't invade were the rows of winter onions you can see in these photos, so it must not like their company.

Love-in-a-Mist

The photos above were taken at the end of May, but you can already see the myriads of seed pods being formed.

Love-in-a-Mist seed pod

The flowers and the foliage of this plant are very delicate and lovely, and so are the seed pods for that matter. They make great vase flowers. This makes it hard to rip them out! Another observation I've made is that whereas the original variety I planted was "Miss Jekyll", which has true blue blossoms, all the self-seeded plants bloomed white and I have no more blue at all.

Love-in-a-Mist

Dame's Rocket also self-seeded, but not anywhere near as prolifically as Love-in-a-Mist, although from the one single plant (purchased in a nursery and planted the fall before) I had last summer there were at least 20 offspring - but not 200. However, the new plants this spring were not as lovely as the original pink-violet plant. The blossoms were not as showy and long-lasting, the plant had less stems, and the color was not as intense. I found a photo showing my single plant of Dame's Rocket last summer, and the second photo shows a couple of its offspring this year. I think you can tell the difference.

Dame's Rocket last year from nursery plant

Self-seeded Dame's Rocket this year

I tried digging up a few plants of Love-in-a-Mist and transplanting them or potting them for the balcony - that didn't work. They didn't survive being dug up well at all. Dame's Rocket, on the other hand, was very easy to transplant, although as was the case with all the self-seeded plants, they just weren't as attractive as the original nursery plant.

Transplanted, self-seeded Dame's Rocket

Conclusion: I will definitely continue to have both these flowers in my garden as they are slug-resistant. However, in the case of Love-in-a-Mist I'll be cutting off the seed pods before they can self-seed, and will grow it from purchased seeds again next year in order to get the lovely blue blossoms. And although self-seeded Dame's Rocket is easy to manage,  I think I'll invest in plants from the nursery again next year.

Another observation: bees and butterflies just love the Love-in-a-Mist.

Slug-resistant plants: Columbine (Aquilegia)

This post is part of my series on dealing with the slug problem. In addition to putting up barriers, I'm concentrating on growing plants that slugs avoid.

Collage of columbine currently blooming in my garden

One of my favorite flowers is columbine (Aquilegia). It has perfect timing, blooming right after the tulips and other spring bulbs have started to look seedy, and before many other summer flowers have opened. It is native to all temperate continents of the Northern Hemisphere, and was first mentioned in Germany, for example, by the famous mystic, healer, and gardener Hildegard von Bingen in the 12th century.

Columbine is easy care, self-seeding without being obnoxious, and beautiful in almost any setting. It's traditional in cottage gardens and can be found in almost every garden in Germany. I've hardly had to purchase any, since it keeps reappearing at various places in the garden, sometimes I suspect blown in from neighboring gardens. I've separated clumps and transplanted them, and I've traded with other gardeners. Right now, at the beginning of May, the garden is full of this elegant flower.

AND - slugs don't touch it. Go figure, since it looks so tender and scrumptious.

There are many varieties of Aquilegia. Its many vernacular names reflect just how widespread and anchored in garden lore this flower is. In English I found granny's bonnet, culverwort, rock bell, rock lily, and honeysuckle (Aquilegia canadensis, not to be confused with some varieties of Lonicera also called honeysuckle). We had Aquilegia in our garden where I grew up in Minnesota, and called it honeysuckle. There are sweet drops of nectar in the blossom spurs, certainly the source of this name.

In addition to the most common German name, Akelei, other names used include Elfenschuh (elf shoe), Zigeunerglocke (gypsy bell), and Narrenkappe (fool's cap).

Knowing how hardy columbine is, last year I bought an almost dead-looking plant from the bargain shelf of the garden center, and have been rewarded this spring with this beauty:

This one is low, but I have a similarly-colored variety that gets much taller and has double blossoms.

Columbine comes in colors ranging from white and pale pink to lavender and red through to dark purple. There are even some cultivars in shades of yellow, but I've never seen one. The kinds I have vary in height between about 30cm and 70cm (12 - 30 inches). The blossoms can be single or double, hanging or upright, and grow at the end of slender stems, sometimes widely spaced, sometimes in clusters.

I just love this tall, pale pink one combined with a lower, blue variety and bleeding heart (Lamprocapnos spectabilis, another lovely slug-resistant flower) in a shady corner of the garden. Aquilegia grows in both shade and sun, but seems to prefer at least partial shade, judging by where it sows itself most copiously.

The tallest columbine I have is white, and truly looks bell-like. I've had to rip some of it out since it was crowding the saxifrage.

The following photos show off the various styles and colors of Aquilegia.

So if you don't have any yet in your garden, go right out and buy some of this versatile perennial. They can be planted or sowed right now.

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.

One year of slug experience - what works, and what doesn't, at least in my garden (including lists of slug resistant plants)

I wrote a post on slugs last year after planting lupins as green manure and watching them get devoured overnight by slugs. This inspired me to do some research on slug management, the result of which was I didn't want to use slug pellets and also didn't want to ruin my karma by constantly slaughtering the creatures. I also found some great books and websites on the subject of slug-resistant plants.

So where am I a year later? First off, we have a really bad slug problem. Our garden is on the edge of a Rhine flood plain and large nature reserve on the one side, and on the other are dozens of other allotments in our garden colony. It truly seemed like a hopeless battle. My main strategy was to plant only slug-resistant flowers and vegetables. After consulting many sources, here are my lists with my personal experience.

Herbs

• chives
• garlic chives
• lavender
• lemon balm
• lemon thyme
• lovage
• oregano
• peppermint 
• rosemary
• stevia
• St.-Johns-wort
• thyme 
• valerian

These all worked pretty well and were mostly avoided by slugs. Exceptions: the stevia was almost annihilated, and the lemon thyme (Thymus citriodorus) was devoured overnight. The peppermint was attacked but survived, but I planted some on our roof deck just to be sure. The stevia I managed to save by putting a snail collar on it - see below, but I gave up on the lemon thyme. Didn't even try parsley or sage.

Vegetables

• cucumbers
• garlic
• lamb's lettuce
• leaf lettuce
• leeks
• onions
• rocket
• tomatoes
• zucchini - I raised the plants from seeds indoors until they were quite large.

The only one of these that was notably attacked were the cucumbers, which were also fine after I put a snail collar on them. Here, too, there were many things I didn't dare try, like cabbage, broccoli, kohlrabi, etc.

Perennials - negative list
I inherited many perennials from my predecessors in the allotment, but also planted some myself. Here are some that were incessantly attacked by slugs to the point that they just looked terrible, despite the fact that some of them are listed by some sources as being slug-resistant:

• all of the at least five types of hostas I had
• Centaurea montana (perennial cornflowers)
• salvia of various kinds
• lobelia of various kinds
• Echinacea of various kinds (coneflowers)
• marguerites
• hydrangeas
• asters
• clematis

Although these flowers survived and even bloomed, I've now thrown them almost all out because I can't bear the way they look after slug attacks.

Perennials - positive list
These flowers weren't touched by slugs:

• dame's rocket (Hesperis matronalis)
• forget-me-not (Myosotis)
• hellebore
• hardy geraniums
• astilbe
• lady's mantle
• roses
• bleeding heart (Lamprocapnos spectabilis)
• columbine (Aquilegia)
• day lilies
• irises
• common bugle (Ajuga reptans)
• alum root (Heuchera micrantha)
• saxifraga of various kinds
• sedum of various kinds

Annuals - negative list

• violas - forget it!
• petunias - I planted some in hanging baskets two meters off the ground and still found slugs in them, god knows how they got there.
• lantana - Wouldn't you think that these prickly, strong-smelling plants would repel slugs - hah!
• sunflowers - By installing snail collars until they were about a meter high I managed to raise amazing sunflowers, but they are definitely beloved of slugs when young.
•  zinnias - Gave up and had them only on the roof deck, where they did beautifully:

Annuals - positive list
These flowers weren't touched by slugs:

• moss roses (Portulaca grandiflora)
• pelargonium geraniums
• impatiens (Impatiens neuguinea)
• nasturtium (Tropaeolum majus)

I also purchased a seed mixture of annuals resistant to slugs called (in German) "Sperli's Schleich Dich Blühende Schneckenbarriere".

This was a fabulous buy and produced many lovely flowers that were not touched by the slugs. Unfortunately, the package does not list what kinds of seeds it contains. I identified the following:

• love-in-a-mist (Nigella damascena), both blue and white
• some kind of rudbeckia
• some kind of snapdragon

I've already purchased another package for next year. Maybe someone can identify the flowers in this mixture more precisely? In the first shot below are what I think are some kind of annual rudbeckia, and in the second shot you can see the lovely seed pods of love-in-the-mist below the rudbeckia, and in the background you can make out the pale blue of still blooming love-in-the-mist. In the lower part of the photo is what I believe to be snapdragons (click to enlarge).

I tried a few other methods of discouraging or getting rid of slugs, and found the following to be ineffective: coffee grounds, watering with moss brew, and beer traps. I also broke down and tried environmentally-friendly ferramol snail pellets. Both beer traps and pellets killed a few, but they were followed immediately by legions more. The only manual method that made a difference was simply gathering them up by the dozens (or hundreds!) at dusk and killing them, not a fun activity.

So my resume: 1) Be more consistent about only growing slug-resistant plants, and 2) snail collars work on plants with the right shape and size.

How about the rest of you?

Snails and slugs and moles, oh my!

After clearing, spading, hoeing, raking and fertilizing the large space where I want to plant my farmer's garden enclosed by boxwood, I first sowed lupins of an annual variety as green manure to fertilize and loosen up the soil.

Every morning I anxiously went out to the garden to water and see if there was any sign of growth. After about a week I was delighted to see that delicate reddish green sprouts were pushing up all over the plot!

But THEN I had the kind of shock that many gardeners go through at some point in their career: one morning many of the shoots had been eaten right down to earth level with a telltale trail of slime leading back to the undergrowth on the edge of the plot. It was definitely the slugs that are rampant here. And most likely the invasive species of Spanish slug (Arion lusitanicus), which is slowly driving out the indigenous German red slug. The Spanish slug is so robust that it often survives standard snail pellets, and is avoided by many natural predators due to its bitter taste.

Whatever - the incident filled me with irrational blind rage and lust to kill. I remembered someone telling me about setting beer traps (scroll down to the disgusting picture) for snails and slugs, so tried that. It at least seemed better than what our predecessors in the garden had done: they sprinkled poisonous pellets everywhere and had rusty pairs of scissors deposited all over the garden for cutting the slugs in half. But I found I couldn't stomach either beer traps or hands-on murder of the creatures.

Once again, I turned to that incredible repository of knowledge, the internet, and ended up ordering two wonderful books that changed my view of things and have led me to try a new, more pacifist approach to the slug issue.

The first book (in German), is entitled "Snail Whispering instead of Snail Pellets", by Hans-Peter Posavac. His thesis, in a nutshell, is that you don't want to spend your time in your wonderful peaceful garden, where you're trying to be at one with nature, being filled with hatred and murderous thoughts towards snails/slugs, much less devising gruesome ways to kill them, so why not try a different approach and learn to live with them. He describes his own odyssey through various campaigns - never really successful - to kill off the slugs in his garden, and his decision to try a new approach. The first thing he did was to find out all about these wondrous creatures, who have been on earth practically unchanged for millions of years, and themselves are completely peaceful, slow, persevering, and goal-oriented in survival. Then he started to practice what he calls "snail meditation", i.e. look for a snail or slug in your garden, then sit down on a mat nearby and just watch it. He found that doing this had a relaxing effect, also making him feel fond of the creatures. Then he started to talk to the snails in his garden.

However, talking to them was just part of an entire routine he developed to get the local snails/slugs (here it's mostly slugs) used to the fact that they should eat somewhere else, not in his flower and vegetable beds. He gathered them all up gently in a flat pan at dusk when they typically go foraging, admonishing them not to eat his plants, and carried them to a prepared feeding place with plentiful nourishment of the kind they prefer such as wilted lettuce, citrus peels, wheat germ, etc. He claims that after a few weeks they gave up and went directly to the feeding station. He also claims that due to genetic collective memory, subsequent generations showed the same behavior.

I'm not sure whether I'll actually begin to talk to my slugs, but I was so impressed by the book that I wrote to the author and offered to translate his book into English. The slug/snail problem is universal, after all. No reply yet. I'm not holding my breath, oh well.

The second book I bought, also in German, has the somewhat cumbersome title "Plants that snails like or avoid and tips for combating snails: The ecological solution to the snail problem - pleasure in your garden instead of snails devouring your plants", by Susanne Sailer. There are also many books and websites in English on this topic, see for example here, or here. Ms. Sailer has written a great book with comprehensive lists of plants that slugs usually avoid, including photos and useful information on planting, colors, height, etc. She did it by conducting an empirical survey of professional gardeners and gardening schools. She also has other good tips on how to lessen your slug problem without resorting to mayhem.

BTW I found out by reading her book that lupins are one of the most preferred meals of slugs. Here are some other things I won't be planting: marigolds, lettuce, radishes, zinnias, petunias. But I can have them on our roof-top patio at home. At least I haven't seen a slug up here on the sixth floor yet! (Click to enlarge.)





And what about moles? Well I mostly put them in to conform to the "Lions and tigers and bears" chant in "Dorothy and the Wizard of Oz", but ominously enough, our predecessors in the garden had installed mole deterrents, i.e. some kind of battery-powered contraption which supposedly sends out signals that moles don't like. Haven't seen a mole or molehill anywhere around, though.