Starbucks vs. slugs

[c-ray]

I just found out that apparently Starbucks has a policy that they will give their used coffee grounds to anyone who asks for them. I also read that used coffee grounds spread over the soil will kill slugs or at least repel them. Coffee grounds are good for compost too and also have a little bit of nutrient value to them and can be spread directly as a mulch, though they are a bit acidic so they should be mixed with some lime. Here's a page from the Starbucks site, note the fertilizer values near the bottom: http://www.starbucks.com/aboutus/compost.asp

[The Cannarchist]

They love their coffee C-Ray.

[c-ray]

really? hmm there goes that theory...

here's what I read:
"Caffeine is present in coffee and cocoa beans to protect the plant against harmful insects, but it is pure chance that it has a toxic effect on molluscs (slugs). Researchers say that they do not know why caffeine killed the slugs. But they suggest it may act as a neurotoxin, since exposed slugs fell to "uncoordinated writhing" before dying. It could be very useful because coffee is not likely to harm people so it's far better than spreading the traditional products, which also harms beneficial insects."

Source: New Scientists
Journal reference: Nature (vol 417 p 915)

[The Cannarchist]

That'll do.

It's costing me a tidy sum in beer to keep those guys happy.

[dpn]

Slugs hate oat bran too... some gardeners tested a variety of methods and oat bran was the most effective. Oat bran could have fungi added to it for an extra bonus top dressing.

[dpn]

BARRIERS

Try lava rock as a barrier in areas where plants need protection. We have heard from many people who say it works very well! Perhaps lava rock is good for something after all? No offense to those who like it.

Use horseradish roots and geranium leaves as barriers. Does this work?

If you have access to a sweet gum tree (Liquidambar) the spiny fruits it produces make a good slug barrier. The American Sweet Gum tree (L. styracflua) is hardy from zone 1 to 12!

Slug-Stop is applied as a 2 inch wide barrier in the same way that you would use diatomaceous earth. Unlike D.E., Slug-Stop does not have to remain dry to be effective. It is made from a patented blend of soaps from coconuts! It does not kill slugs and snails but keeps them out wherever you use it. After 3 or more weeks as needed you just put down more where there are any breaks in your original barrier. It is recommended that the barrier be outside of the root zone of the plant to be protected as Slug-Stop does contain some naturally occurring salts that some plants may be sensitive to. It has a low impact on the environment. It is claimed that it break down naturally into the soil with no residual problems.

Use the lint from your dryer as a barrier. If you are concerned about any chemicals in the fabric softener do this instead: add 4 ounces of white vinegar to the final rinse water in the washing machine. Your clothes will be static free. There will be no vinegar smell as the odor completely evaporates. No kidding, this really works great.

Use cedar, oak bark chips or gravel chips which will irritate and dehydrate them.

Try a barrier line or an overall sprinkle of powdered ginger.

Use wood ashes as a barrier around plants, however try not to let the plant come into contact with the ashes. The ashes act as a desiccant and dry the slugs up.

Shingles or Sandpaper: Get rid of slugs in the infested area then lay a barrier of roof shingles around the area to keep slugs out or use a circle of sandpaper.

Spread well crushed eggshells around the plants. The calcium released from the eggshells is an extra benefit that "sweetens" the soil. The sharp edges of the shells will kill slugs. Most folks report that this does not work well.

Sprinkle a line of lime around your plants. A pile of unaged animal manure has an high acidity and provides a slug breeding haven leading to the assumption that slugs and snails are more of a problem in acid soils. By applying lime we sweeten the soil making it more alkaline and deterring the slugs. Obviously this won't work around plants requiring a more acidic soil.

Talcum powder and diatomaceous earth work as a barrier too. Diatomaceous earth will kill earthworms though and you do not want to breath it. Please be careful when using DE.

Hardware Cloth: On raised beds staple strips of hardware cloth on wood bordered beds. Extend the cloth about 2 inches beyond the edge making sure the sharp points will be encountered by slugs trying to climb over. It rips them up. You can also use aluminum screening material in the same manner. You can push the barriers directly upright into the soil for borderless beds.

Copper Strips: The use of copper strips as a barrier will give slugs a jolt of electricity. The metal ions in copper are what repel slugs. There are mixed reports on just how effective this is. One good way to try copper strips is to make a circle of the strip around just the plants you want to protect, remove slugs first. Easier too. Copper sulfate and similar copper based products may also work for the barrier method.

Herbs: A mulch made of stems and leaves of strong smelling herbs like wormwood, mints, tansy, lemon balm along with conifer twigs mixed in will help stop slugs and other pests.

Hair and Fur: Use a barrier of hair or fur to entangle slugs. Gross and effective. An additional benefit from using hair is that it supplies some nitrogen to your plants! Human hair, pet fur and horsehair, all will work.

Prunings: Another possibility could be to use prunings from raspberries, blackberries etc. Anything with fine, sharp stickers may help.

Quack Grass: Quack Grass damages the nerves slugs use for feeding. Chop it up and use it as a mulch. Make a tea by cutting it up, soak in 1 quart of warm water for 24 hours, then use as a barrier spray on soil. Don't spray directly on plants. The use of Quack Grass has, personally, worked very well for us. See more on using Quack Grass for recipes.

Oak Leaves, Lettuce and Cabbage: Using oak leaves as a mulch deters slugs, so does seaweed if you have access to some. Also of interest is that red oak leaf lettuce is not bothered by slugs or snails! Red oak leaf is tasty and can take some hot weather. Also of interest we observed that slugs were all over green cabbage, but the red cabbage was left alone!

Coffee Grounds: Used coffee grounds spread around susceptible plants may work.

Epsom Salts: Epsom salts sprinkled on the soil will supposedly deter slugs and also helps prevent Magnesium deficiency in your plants. Magnesium helps to deepen color, thickens petals and increases root structure.

Oat Bran: Scatter oat bran on the soil to kill slugs and snails.

Builders Sand: Try barriers of builders sand which has a sharp texture.

Nut Shells: Ground shells of filberts, pecans and walnuts may work, if you can find a source or grind your own.

Cocoa Hulls: Cocoa shell mulch may work as a slug deterrent as well as supplying nitrogen to the soil as it breaks down and it suppresses weeds too! We've had mixed reports of people using cocoa shells for slug control. Some folks say it works fine to fairly well and some say the slugs love it so much that they are all over it and their slime creates a hard crust on top of the mulch! We will suggest that you buy a small amount of cocoa shells and try it out first.
Warning: Dogs may be attracted to and can eat cocoa hulls which can be fatal!

Rosemary: Sprigs of rosemary scattered around repel slugs and are refreshing with their piney scent.

Mullein & Slugs: (click here for our test report) Fresh or dried mullein (verbacsum) leaves placed around vulnerable plants and areas repels slugs and snails. Mullein is also a nice tall accent for use as a background planting.

Pine Needles: Try a mulch of pine needles which works well around strawberry plants

[c-ray]

I haven't tried the oatbran but I was told the slugs eat it and dry up

[CottonBalls]

If you make a simple ring of playground sand around the plant a slug will not cross that line.....if it tries it will die.

Better yet is fresh beach sand with it's saline content....we all know salt will dissolve a slug.

[vapor]

hey cb i discovered the sand trick this year works well!!

[c-ray]

I post this because in the wet coast we have problems with slugs living and breeding in compost piles and mulches, maybe this can help

Caffeine as a novel toxicant for slugs and snails

Caffeine can be used as a natural source of control for snails and slugs. Be mindful however that 1-2% caffeine is a lot of coffee

Hollingsworth RG. Armstrong JW. Campbell E.

Annals of Applied Biology. 142(1):91-97, 2003.

In this study, caffeine is shown to act as both a repellent and toxicant against slugs and snails. This research is the first to document the potential of caffeine as a molluscicide. A drench treatment using a 1% or 2% solution of caffeine caused 100% of slugs (Veronicella cubensis) to exit treated soil, and the majority of these slugs subsequently died from caffeine poisoning. A 2% solution of caffeine applied to the growing medium of orchids killed 95% of orchid snails, (Zonitoides arboreus), and gave better control than a liquid metaldehyde product representing the standard commercial control for this pest. Using leaf-dip bioassays, we discovered that slugs tended to avoid feeding on plant material treated with caffeine solutions greater than or equal to0.1%, and caffeine solutions as low as 0.01% significantly reduced overall feeding by slugs.

Due to concerns about chemical residues, available molluscicides generally cannot be applied directly to food crops for control of slug and snail pests. Caffeine is a natural product which is approved as a food additive. Therefore, caffeine may prove useful for protecting food crops from slugs and snails. [References: 24]

[c-ray]

from http://www.sunset.com/sunset/garden/edible/article/0,20633,1208232,00.html

The Starbucks coffee compost test

Lab report: Those free grounds really are good for your soil

Used coffee grounds make good soil amendments. That’s the buzz among gardeners lately. But what do your coffeepot’s leftovers really add to the soil?

To find out, Sunset sent a batch of Starbucks’ used coffee grounds — the company gives them away for free — to a soil lab for analysis. Turns out the grounds provide generous amounts of phosphorus, potassium, magnesium, and copper.

They also release nitrogen into the soil as they degrade. And they’re slightly acidic — a boon in the Western climate.

Dig or till them into the soil to a depth of 6 to 8 inches.


FULL REPORT

The following information was developed for Sunset by Soil and Plant Laboratory Inc., Bellevue, WA.

Summary: Use of Starbucks coffee grounds in amending mineral soils up to 35 percent by volume coffee grounds will improve soil structure over the short-term and over the long-term. Use of the coffee grounds at the specified incorporation rates (rototilled into a 6- to 8-inch depth) will substantially improve availabilities of phosphorus, potassium, magnesium and copper and will probably negate the need for chemical sources of these plant essential elements.

The nitrogen, phosphorus, potassium “guaranteed analyses” would be as follows for the coffee grounds:

Nitrogen: 2.28 percent
Phosphorus: 0.06 percent
Potassium: 0.6 percent

Available nutrient levels: The pH or reaction of the coffee grounds is considered slightly acidic and in a favorable range at 6.2 on the pH scale.

Salinity (ECe) is a measurement of total soluble salts and is considered slightly elevated at 3.7 dS/m. The primary water-soluble salts in this product are potassium, magnesium, sodium and chloride. The potentially problematic ions in sodium and chloride are each sufficiently low as to be inconsequential in terms of creating problems for plants.

The availabilities of nitrogen, calcium, zinc, manganese and iron are quite low and in some cases deficient. Thus, the coffee grounds will not supply appreciable amounts of these essential plant elements when used as a mineral soil amendment.

However, the availabilities of phosphorus, potassium, magnesium and copper are each sufficiently high that there will be a very positive impact on improving availabilities of these elements where the coffee grounds are used as a mineral soil amendment. The coffee grounds will negate the need for additional sources of phosphorus, potassium, magnesium and copper when blended with mineral soils.

In summary, the available plant essential elements which will be substantially improved where the coffee grounds are used as a soil amendment, include phosphorus, potassium, magnesium and copper.

Total nutrient levels: Each cubic yard of these coffee grounds contains a total of 10.31 lbs. nitrogen, of which 0.01 lb. (0.09%) are available. Thus, even though available nitrogen is considered deficient in this product, there still remains over 10 lbs. of total nitrogen per cubic yard of coffee grounds. Thus, nitrogen is primarily bound in the organic fraction and is unavailable to plants until soil microorganisms degrade the organic fraction. Through this process, the nitrogen is converted to plant available forms. Over the long term the coffee grounds will act like a slow release fertilizer providing long-term nitrogen input which can then be utilized by plants.

Nearly all potassium and all magnesium are in the available forms. This means that immediate availability improvements for these two elements will take place when the coffee grounds are blended with mineral soils. About half of the copper and calcium are in their immediately available forms.

All other plant essential elements are primarily bound in the organic fraction and will thus be subject to slow release over time as soil microbes continue to degrade the organic fraction.

Physical properties: Virtually all particles passed the 1 millimeter (mm) screen resulting in a product which is very fine textured. Each cubic yard of the coffee grounds will supply an excellent amount of organic matter, measured at 442 lbs. organic matter per cubic yard. At the use rates indicated in this report, the input of organic matter will be substantial and will result in considerable short-term and long-term improvement of mineral soil structure.

Carbon/nitrogen ratio: On the basis of dry matter bulk density (452 lbs. per cubic yard), organic matter content (97.7%) and total nitrogen (2.28%), the estimated carbon/nitrogen ratio is about 24:1. This means that there is more than sufficient nitrogen present in the coffee grounds to provide for the nitrogen demand of the soil microorganisms as they degrade the organic fraction.

Use rate: Based on the overall chemistry and physical properties of the coffee grounds, they can be utilized at rates similar to other organic amendments when used in amending mineral soils. These data indicate that 25-35 percent by volume coffee grounds can be blended with mineral soils of any type to improve structure of those soils.

[c-ray]

for future reference...

from http://www.jstage.jst.go.jp/article/jos/55/1/55_31/_article

Deodorization of Ammonia by Coffee Grounds

Naohito KAWASAKI1), Hideo KINOSHITA2), Takashi OUE2), Takeo NAKAMURA1) and Seiki TANADA1)
1) School of Pharmaceutical Sciences, Kinki University
2) Kokubu Hospital

(Received March 7, 2005)
(Accepted August 12, 2005)

Abstract: Coffee grounds are a vegetable biomass that can be efficiently burned. The carbon dioxide generated by burning coffee grounds is affecting global warming. On the other hand, ammonia generated in the places such as toilets or farms produces a bad smell. In the present study, we have analyzed the possibility of ammonia elimination using the carbonaceous materials produced from coffee grounds. Carbonaceous materials were prepared by the microwave treatment of coffee grounds. We observed that the saturated amounts of ammonia adsorbed by some of the carbonaceous materials produced from coffee grounds were greater than that adsorbed by activated carbon. In contrast, the activated carbon adsorption rate for ammonia was higher than those of the carbonaceous materials. Therefore, carbonaceous materials produced from coffee grounds could be utilized for the removal of ammonia in the gaseous phase.

and

from http://www.ingentaconnect.com/content/ap/cs/2002/00000254/00000001/art08570

[QUOTE]
Adsorption of Dyes onto Carbonaceous Materials Produced from Coffee Grounds by Microwave Treatment

Authors: Hirata M.1; Kawasaki N.1; Nakamura T.1; Matsumoto K.2; Kabayama M.3; Tamura T.4; Tanada S.1
Source: Journal of Colloid and Interface Science, Volume 254, Number 1, October 2002, pp. 17-22(6)
Publisher: Academic Press


Abstract:

Organic wastes have been burned for reclamation. However, they have to be recycled and reused for industrial sustainable development. Carbonaceous materials were produced from coffee grounds by microwave treatment. There are many phenolic hydroxyl and carboxyl groups on the surface of carbonaceous materials. The base consumption of the carbonaceous materials was larger than that of the commercially activated carbon. The carbonaceous materials produced from coffee grounds were applied to the adsorbates for the removal of basic dyes (methylene blue and gentian violet) in wastewater. This result indicated that the adsorption of dyes depended upon the surface polar groups on the carbonaceous materials. Moreover, the Freundlich constants of isotherms for the adsorption of methylene blue and gentian violet onto the carbonaceous materials produced from coffee grounds were greater than those for adsorption onto activated carbon or ceramic activated carbon. The interaction was greatest between the surface or porosity of the carbonaceous materials and methylene blue and gentian violet. The microwave treatment would be useful for the carbonization of organic wastes to save energy.

[c-ray]

last one

from http://www.bigpumpkins.com/MsgBoard/ViewThread.asp?b=20&p=140941

I've got a deal with our neighborhood Starbucks to collect their used grounds for the patch. I had a sample of the grounds analyzed (manure analysis) at Midwest Labs. Here are the results

Analysis
N .74%
P .11%
K .18%

S .05%
Ca .04%
Mg .06%
Na .00%
Cu 7ppm
Fe 32ppm
Mn 15ppm
Zn 4ppm

pH 5.9

Nutrients lbs/ton

N 14.9
P 2.1
K 3.6
S .9
Ca .9
Mg 1.2
Na 0.0
Cu .01
Fe .06
Mn .03
Zn .01

First Year Availability (lbs/ton)

N 5
P 1
K 3
S 0
Ca 1
Mg 1
Na 0
Cu .01
Fe .04
Mn .02
Zn 0

[smokinbasser]

I don't grow outdoors but I also had heard about copper and slugs, I read to use 1/2" copper tubing and 90 degree fittings and make an encompassing rectangle to surround the base of the plants, after harvest remove the copper "ring" and redeploy for next crops. This thread is a very informative thread for outdoor growers with slug issues.