Reprint from my post on Boxed Dirt:
Last week at my Urban Harvest’s Organic Vegetable Series class, Dr. Bob Randall shared his thoughts on fertilizers. Now this is a subject I’ve been very interested in. Given the transition I’ve made from synthetic to organic fertilizers over the past decade. Long gone are the days of using Miracle Gro for me!
From Organic Gardening Magazine, July/August 2000 Issue:
“Miracle-Gro is a synthetic fertilizer that contains ammonium phosphate and several other chemicals that can be toxic to your soil and plants. It is prohibited from use in certified-organic farming.” Read more about this on Dave’s Garden.
Ok. Would you want to put that on food you are growing? Umm. No thank you. In fact I would not want to put that anywhere in my garden.
The top recommendation in the class was MicroLife™ a balanced organic fertilizer. It’s local too, from San Jacinto Environmental Supplies. It is a slow release so it will not burn the roots. It can be used on all plants, including turf grasses, tree and shrubs. Granulated, homogenized with 2% Fe, 70 trace minerals, enzymes and beneficial microorganisms, including Endo and Ecto Mycorrhizal. It can be found at these local retailers. Around $33-$36 per 40 lb bag.
Several other brands were mentioned including Soil Food from Garden-ville, Lady Bug, Hi-Yield Cottenseed Meal, Earth Essentials by Southwest Fertilizer and Rabbit Hill Farms (available at Wabash). All are good balanced organic fertilizers. Arbor Gate Nursery in Tomball has their own Organic blend that may be worth a look too. It sells for $24.99 for a 40 lb bag. That was the most important thing I learned last week. Keep it balanced. Unless you have a very good reason to, do not add minerals separately. That is how things can get out of wack in your garden. The reasons for this have a lot to do with how minerals interact with each other. For example, excess calcium in the soil ties up magnesium and excess phosporous ties up calcium. Excess potassium ties up sodium, iron and manganese. You can see how adding too much of one mineral can easily cause a cascading effect leaving your plants unable to access what they need in the soil.
Since my raised bed gardens are new (Project 802 started in August 2009), I will add 1 cup per square foot of Microlife™ to top 6 inches of soil. Preferably it is a good idea to do this a few weeks before planting. This is only needed for the first year. After that, mulching, leaf-mold compost and a few sprinkles of organic fertilizers is all that is needed.
So this past Saturday, I headed over to Wabash Feed Store and bought a bag of MicroLife™. This weekend, I will add it to my beds. One 40 lb bag yields about 100 cups of fertilizer. How do I know that? The good folks at Wabash actually opened a bag and weighed a cup of fertilizer for me (6 ounces), so 40 lbs x 16 ounces = 640 ounces / 6 = 106 cups.
They have great customer service. I have 3 4×8 raised beds, so I will need about 96 cups if I am using 1 cup per sq ft of surface area (32 sq ft x 3 beds = 96 sq ft).
What fertilizers are you using in your raised vegetable beds?