I know I can't be the only one not able to find dolomite, and looking for information on substitutes. Are some of you using something different in your homemade self watering containers now that dolomite is not out there?
Lily
Dolomite
Home Depot, Lowe's, Ace Hardware, the local co-ops, the local plant nursery, even Walmart carries it around here. Many sources available online if you don't mind paying the shipping of course. You can also check with any local landscapers as they almost always have it for lawn care.
HTH
Dave
'scuse my ignorance, but isn't dolomite also known as garden lime, agricultural lime, dolomitic lime: as the SOURCE of the lime is from either dolomitic or calcitic (sp?) rock?
Dolomite (aka garden lime) is composed of calcium and magnesium carbonate. Generally, agricultural lime is calcium carbonate. Ideally, the Ca:Mg ratio in dolomite will be somewhere between 5:1 and 2:1, Ca:Mg. It's very widely available in the spring wherever fertilizxer is sold. You can buy it in 50 lb bags or pay a 50 lb bag price for 6.75 lbs of the same product packaged by Espoma. It's available in powdered form or prilled. The prilled form is simply the powdered product mixed with a liquid binder to form a slurry. The slurry is then 'shot' from prilling towers where the slurry forms little balls and dries as it falls. The prilled product works better for broadcast application and reverts to it's powdered form as soon as it gets wet.
Al
This message was edited Apr 2, 2015 5:16 PM
This message was edited Apr 2, 2015 5:42 PM
Thanks Al
So: garden lime is dolomitic (?) while agricultural lime is calcitic (?).
I'm still kinda confused; all I remember is that when I went to go get some lime (for my 'maters) I was told to get the dolomitic lime. So I did, but am still rather fuzzy about WHY!
Can't speak for Al but my understanding is the "why" is because they are different forms of calcium, one more readily absorbed than the other, and different particle sizes so faster acting. The dolomite is more readily absorbed by the plants, faster acting, than is calcium carbonate. Plus the magnesium it contains is also beneficial for tomato plants and such.
However, many things are sold labeled as "garden lime" and not all of them are dolomite.
Dave
The size difference between the CaCO3 and MgCO3 molecules causes the calcium carbonate and magnesium carbonate to be laid down in dolomite in alternating layers. The Ca fraction in dolomite is the same material as in agricultural lime - calcium carbonate, so it's solubility doesn't differ from that of other sources of CaCO3, so it wouldn't be faster acting or more available except as allowed by any difference in particle size, the primary factor bearing on solubility in growing situations. FWIW - the MgCO3 fraction of dolomite is more than 100X more soluble than the CaCO3 fraction.
BetNC - The reason one might be instructed to use only dolomitic lime has to do with an antagonistic relationship between Ca and Mg in soils. An antagonism occurs between 2 nutrients when the amount of one (in the soil) impacts uptake of the other. An excess of Ca can cause an antagonistic deficiency of several nutrients, but mainly Mg. An excess of Mg can cause an antagonistic deficiency of mainly Ca, but K as well, and a Mg excess can cause greater availability of P. If you apply lime other than dolomite, you risk creating a deficiency of Mg, which is why you might be advised to make sure you get dolomite - especially for container culture applications. Since dolomite already has Mg in it, the risk of creating a Mg deficiency via dolomite is practically nil. OTOH, you should be advised that indiscriminately dosing plants with Epsom salts has no potential to benefit unless there is a Mg (or S) deficiency, and the potential for creating a Ca deficiency (because you're supplying Mg w/o giving consideration to the Ca:Mg ratio) is great. When you add a little more of any nutrient, if it's a little more than needed, it has only the potential to limit.
Espoma garden lime: http://agr.wa.gov/Pestfert/Fertilizers/FertDB/prodinfo.aspx?pname=4898
Al
Found it. It is called Epsoma Garden Lime in our area and it is necessary to read the ingredients on the bag to find out it is dolomitic lime which contains both calcium and magnesium in the correct proportions for tomatoes and many other veggies. I have not found anything called dolomite in my area, although I used to find it at Pike's Nursery only.
I was also able to find out that I need 1 pound of the Epsoma Garden lime per 18 gallon box, mixed into the top 3 to 4 inches of mix (1/3 peat, 1/3 perlite, and 1/3 coconut coir in our boxes), along with a fertilizer strip on the top filled with two cups of granular balanced fertilizer or 3 cups of organic. Note please that the Epsoma is measured by weight and the granular fertilizer by the cup.
Anyway I spent the better part of a day locating it and, as a result, have gotten acquainted with a local organic master gardener who works for my county and wants to follow how our first attempt at straw bale gardening is going. It's always nice to make new friends,
Some organic gardening sites claim that Borax and Epsom Salts can be substituted for dolomite, but my new organic master gardening friend warned me that boron (the element present in Borax) is only a trace element available to plants in soil, and too much can be very harmful. It must be used cautiously.
Thank you all for sharing what you know. I appreciate you.
Lily