Dear Ruth,

I would like to fertilize my 4 pecan trees. I read up online and came across the product “Zeolite” which contains several minerals. Is this a safe organic product to use?

Thanks for your help,
Sharon Phillips



Ripe pecans on the tree (photo © Corey Leopold on Flickr – use permitted with attribution)
Dear Sharon,

I had not heard of this product prior to your letter, so I checked on the OMRI website to see what I could find out. OMRI, the Organic Materials Review Institute (OMRI) is a national nonprofit organization that determines which input products (things you add to the ground or put on the plants, etc.) are allowed for use in organic production and processing.

Product producers must pay a fee to have their product reviewed by OMRI, so there are products that are allowed for organic production but simply have not been reviewed by OMRI because of the cost. If you have ever tried to unearth details about which products are OMRI allowable, the uninitiated (me) will experience a labyrinth-like exercise in patience and determination…unless of course you are looking a product with OMRI printed on it. You will sometimes see “allowed by NOP” on advertised products. There is a National List of Allowed Substances under the USDA’s National Organic Program (NOP). If the OMRI site whets your appetite, check out this huge website with hundreds (thousands?) of pages detailing National Organic Program Standards for some really great fun on a Thursday night!

Now to get to your question Sharon…gleaning from the OMRI listing for Zeolite, ZEOLITE, or sodium aluminosilicate, comes in both synthetic and non-synthetic forms. For Certified Organic growers, the non-synthetic form is currently allowed (1) as a Crop Fertilizer and Soil Amendment/ Crop Management Tool and Production Aid without restrictions, (2) as a Livestock Feed Ingredient with restrictions, and (3) as a Pesticide with restrictions. The synthetic form of Zeolite is not allowed in organic production.

Zeotech describes ZeoMax® Garden Aid as “a naturally occurring mineral containing a cage-like structure which may help promote plant growth by enhancing nutrient availability, soil conditioning, and improving soil moisture holding capacity.” The product claims to helps hold and slowly release valuable plant nutrients, helps reduce watering by retaining soil moisture, improves aeration of the soil and minimizes compaction, improves strong root development, is stable in the soil and ecologically safe, and supports beneficial microbe activity in the soil.

AZOMITE is a different product that is often used on fruit trees for its more than 70 trace minerals and elements. Azomite, technically hydrated sodium calcium aluminosilicate, is described by the seller as “A to Z of Minerals Including Trace Elements”. Azomite is OMRI-approved with no restrictions as a Crop Fertilizer and Soil Amendent, and with some restrictions as a Livestock Feed Ingredient. Synthetic hydrated sodium calcium aluminosilicate is not allowed for certified organic production.

Michael Phillips, fruit grower and author of The Holistic Orchard, adds about one pound of Azomite to his planting holes for fruit trees, forks it into his compost pile in late summer, and boosts severely disease-ridden trees by applying generous amounts – up to 15 pounds per tree – of Azomite throughout the tree’s dripline in late summer.

The non-synthetic types of Zeolite and Azomite have both been approved by OMRI for Organic Production, and could safely be used on your pecan trees. Neither Zeolite nor Azomite will take the place of macro-nutrient fertilizer (NPK-Nitrogen/Phosphorus/Potassium), but they should provide some of the trace elements and minerals needed by the plant, thus allowing the plant to achieve better nutrient uptake and ideally produce more and better pecans.

What a treat to have pecan trees!

Wishing you a big harvest,


Ask Ruth © 2012 Ruth Gonzalez & Organic Growers School

Ruth Gonzalez is a former market farmer, gardener, local food advocate, and founder of the Tailgate Market Fan Club where she blogs at In her job at Reems Creek Nursery, Ruth offers advice on all sorts of gardening questions, and benefits daily from the wisdom of local gardeners.

Author: Ruth Gonzalez

Ruth Gonzalez is a former market farmer, gardener, and local food advocate who wants to see organic farms proliferate and organic gardens in every yard. She also served on the Organic Growers School Board of Directors. In her job at Reems Creek Nursery, Ruth offers advice on all sorts of gardening questions, and benefits daily from the wisdom of local gardeners.

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