Diatomaceous Earth?

I visited my local farm and ranch feed store today to pick up a 50 lb. bag of organic 6-2-4, slow release fertilizer. I simply want to mess around with the fertilizer and see what it will do. While at the store, I noticed he also had fifty lb. bags of Diatomaceous Earth. I know from past posts that DE is good to control snails and slugs in the flower beds and garden. I learned it is also a good control of ants, fleas, and other insects with exoskeletons. I am curious if gardeners ever use it as a mineral (calcium) additive in their gardens. The DE is pretty inexpensive when purchased from a feed mill. They also have kelp meal in 50 lb. bags which I will need to investigate. I've read of many gardeners using kelp in their gardens and compost piles. I would appreciate comments on the kelp also.

Ted

[travis]

I've used DE in place of perlite in potting mix. The nearly microscopic hole through the middle of the skeleton structure holds nutrient rich moisture while the coarse structure of the material facilitates quick drainage. I cannot comment on DE with regard to its value as calcium.

Travis,

I've read that mined DE is pulverized into a powder before packaging. Do you believe it retains enough microscopic structure to facilitate the actions you describe after being pulverized? The only action I've read it retains from its original form is microscopic sharp edges which provide its action against slugs, snails, and insects.

Ted

[travis]

Originally Posted by tedln

Travis,

I've read that mined DE is pulverized into a powder before packaging. Do you believe it retains enough microscopic structure to facilitate the actions you describe after being pulverized? The only action I've read it retains from its original form is microscopic sharp edges which provide its action against slugs, snails, and insects.

Ted

Ted, the DE I'm most familiar with is used for filtering swimming pool water and retains its natural structure which is how the system filters the water by pressuring it through the tiny single cell holes in the calcarious skeletons.

The only other kind of DE I've used was sold as an oil absorbing product for motor garage floors and it too has the characteristic single cell skeletal structure.

[ireilly]

I've read several things here and other places, but I feel that since you said this showed a filter, I think piegirl's caution is warranted, as the excerpt from Wikipedia shows (not that it is always right, but this is info repeated in several places):

From http://en.wikipedia.org/wiki/Diatomaceous_earth :

Safety considerations

The absorbent qualities of diatomite can result in a significant drying of the hands if handled without gloves. The flux-calcined form contains a highly crystalline form of silica, resulting in sharp edges. The sharpness of this version of the material makes it dangerous to breathe and a dust mask is recommended when working with it.
The type of hazard posed by inhalation depends on the form of the silica. Crystalline silica poses a serious inhalation hazard because it can cause silicosis. Amorphous silica can cause dusty lungs, but does not carry the same degree of risk as crystalline silica. Natural or dried diatomite generally contains very low percentages of crystalline silica. Diatomite produced for pool filters is treated with high heat (calcining) and a fluxing agent (soda ash), causing the formerly amorphous silicon dioxide to assume its crystalline form.
The crystalline silica content of the dust's particulate is regulated in the United States by the Occupational Safety and Health Administration (OSHA), and there are guidelines for the maximum amounts allowable in the product and in the air near the breathing zone of workers.[

[RinTinTin]

A word of caution here:

While DE is a good deterrent to slugs/snails, that same abrasive quality will also do in your earth worms. They will die of dehydration from those multiple gashes to their skin. DE also will not work after a rain, heavy dew, and will need to be reapplied each time it gets damp.

[fortyonenorth]

tedln -

You didn't mention whether you had specific soil issues you're trying to address. Are you trying to increase fertility, build organic matter or ???

Before amending your soil, do yourself a big favor and get a soil test and find out what you really need. It'll be the best $20 you've ever spent on your garden. I highly recommend Logan Labs in Ohio, because I like they philosophy, but there are many others.

In answer to your specific questions...

DE contains a variety of trace elements such as iron, boron, manganese, copper and zinc - all of which are required (in very small amounts) for a healthy, well-balanced soil. It also contains about 19% calcium and 3% magnesium - again, both of which are required.

Do you know what grade DE your supplier was offering? The most common type, is the finely ground powder used for insect and slug control. A much better bet, in my opinion, is what's referred to as horticultural grade DE. The particle size is much larger - anywhere from roughly 1/32" for a #1 grade to 1/4" for a #2 grade. It's used for potting mixes, but I haven't heard of it being used on a large scale as a soil amendment - though I believe it's similar in some respects to calcined clay products such as Turface, which I love, love, love as an amendment.

Kelp is provides a small bit of potassium and many trace minerals. It's used as a foliar feed and as a soil amendment. I mix it 50/50 with greensand in my garden - again, chiefly for the micronuts.

Rich

Rich,

I have tested my soil and it is in good shape. I simply like to experiment with different things and see what results I can obtain. Often we think the big box stores and garden supply stores are the only option for many common garden products. They typically sell small quantities for high prices. I want to experiment with some products that can be obtained in large quantities at low prices from Farm & Ranch stores. My ultimate goal isn't to create good garden soil. It is to maintain or improve good soil with common products. I rebuild the soil in my raised beds every fall and let it sit through the winter with a cover crop.

I didn't check the bag for information regarding the grade of the DE. It had a sketch of a filter on it, so I assumed it was being sold as a filler for a filtration system.

Ted

[fortyonenorth]

If you haven't tried it already, I'd really recommend adding some calcined clay. It's sold under the brand names Turface and Pros Choice - both as infield conditioners for baseball fields. I think you can also find it in auto part stores, such as Napa sold as Quik-Dry or something like that. It's use it for soaking up gasoline, oil or other spills. I used it on my pepper beds this past season and I was really impressed.

Originally Posted by fortyonenorth

If you haven't tried it already, I'd really recommend adding some calcined clay. It's sold under the brand names Turface and Pros Choice - both as infield conditioners for baseball fields. I think you can also find it in auto part stores, such as Napa sold as Quik-Dry or something like that. It's use it for soaking up gasoline, oil or other spills. I used it on my pepper beds this past season and I was really impressed.

I think most people agree with you about the use of Turface to retain moisture. As a calcined clay, it is highly porous and retains its structure when wet over long periods. A test on a different forum compared the oil dry products and kitty litter which are also a form of porous clay against the Turface and found the other products would not maintain their porous structure when wet over long periods. I think people were looking for an easily available, inexpensive, replacement for Turface due to it's scarcity and cost. I would have no idea where to shop for products designed to condition ball fields.

I'm watching the Texas Rangers / Tampa Bay ball game right now and the infield base paths and pitchers mound are constructed of Turface. I guess I could hang around a professional ball field after the season is over and wait for them to throw the dirt out.

Ted

[RinTinTin]

The dust is harmful if breathed. Some hobbyist chicken raisers use it to control lice & mites. I totally disagree with that use, as I worked on a large egg farm in South America that had experimented with using it. They started losing a couple thousand hens a year due to respitory problems. They discontinued the DE, and the respiritory problems vanished.
As I mentioned in a previous post, it will kill your earthworms, so say goodbye to good tilth.

[casino]

Hi good question, DE can be tricky stuff not all DE is created the same. There are 2 kinds of DE. First there is food grade. It is mined and crushed into a fine power and sold as a nutrient suppliment to farm animals and the same food grade DE is sold in health food stores to help clean the colon and get rid of parasites. The second form of DE, is mined and crushed then it is processed in extreme heat to change its molectular structure to resemble glass and the purpose of this altered form is to be used in swimming pool filters. Match the product for your intended use. Food grade DE is fine for plants and animals. Heat treated DE is safe when used in swimming pool filters but it is NOT safe when used in the garden. The dust can give you lung cancer that is not reversable, causing a long and painfull death, UGH. That being said here is my experience using food grade DE on raspberries.

Organic gardeners love DE because there are no chemicals and it kills bugs. In the past I have used food grade DE on my raspberries to control japanese beetles. It works but there can be problems. DE does wash off in the rain but not all of it. It can leave a white stain residue on the leaves and on the inmature berries. Not a big deal, its food grade, it wont kill you but when used on raspberries this very fine white film remains on the mature red berries it becomes unsightly. I ate the berries and they were fine but not pretty if you intend to give the berries away or sell in a farmers market no one will touch them. For me. I dont use DE any more.

Kelp, good stuff, lots of micro nutrients but dont go over do it. If one cup is good then 2 cups is better, not really. Kelp contains a growth stimulant thats why your plants take off grow like gang busters and look lush and green but an over stimulated plant produces soft tissue and can attract insects. Like my Russian friends say, little little. Using kelp is like having a cup of starbucks coffee in the morning. One cup and I'm good all day.

Hope this helps, good luck.

I was back at my local Farm & Ranch supply the other day and took a good look at the 50 lb. bags of DE he sells. They are labeled "food grade". They also say "less than 0.01% of calcined silica on the bags. I asked the store owner what he kept the DE for and he said his customers feed it to their horses for worming. It made me think of RinTinTin's warning about what it can do to the earth worms in my garden. I asked how much the bags sell for and he said they sell for $22.00 per bag but he has an open bag he would give me. I asked why he has an open bag and he said he opened one to give a guy some to control ants around his house. I told him I would never be able to use almost fifty lbs. of DE. He looked around and found one of those large, plastic, Folgers coffee cans. Filled it with DE and gave it to me.

I now have a large coffee can of DE and since I don't want to slice my earth worms up, I have no idea what to do with it. Any ideas how I can use it in my garden without harming anything?

Ted