I joined/registered for http://forum.earthbox.com someone here on davesgarden mentioned and here is what Steve Lott (Earthbox Education Specialist) said about organic fertilizer:
"Whether organic or chemical fertilizers are used, the EarthBox was designed for dry granular fertilizers, placed on top of the potting mix, which will slowly diffuse to the roots of the plants during the growing season. Fertrell and Nature Safe are both organically certfied dry granular fertilizers."
I have always been mixing the fertilizer in the potting mix throughout since the earthbox instruction said to do so.
Also I'm not sure what "granular" organic fertilizer is... I guess all the organic fertilizers I've bought are kind of grainy (more like sandy) so would that equate to "granular"?
There is more to the thread (The thread is called "Organic Fertilizer" under "Questions and Answers") but I wasn't sure about the copy rights and stuff, so I didn't cut and paste the whole thing.
Anyway, I wanted to hear opinions from others who are using organic fertilizer in earthboxes. Have you been putting the organic fertilizer on top? I wonder if it makes any difference? It's too late for me because all my earthboxes execept for one have already been set up with plants for this season but I am curious to know.
Thanks!
tmm
Organic Fertilizer for EarthBox - Their comment
Well tmm99, I read that message at the link you provided and it seems to me that Steve should get on the same page as the writer of their instruction sheet which says just the opposite, mix 3 cups into the potting mix before planting. This will be my 4th year of doing just that and the various pics I have posted of many of my EB's should attest to the results obtained by mixing it in before planting. I am not familier with Fertrell or Nature Safe, neither is sold in NJ. I use Espoma Garden-tone 5-3-3 100% organic. Since only 1 part of the 5 parts of nitrogen is water soluable in the Espoma, the balance must be released by bacterial action in the soil in a slow even manner over a fairly long period of time. Striping it on top would prevent most of that from happening. Also the phosphate is natural rock phosphate which again releases very slowly in the soil, not on top of it. Same with the potash which is potassium-magnesium sulfate and kelp meal.
In chemical fertilizer pretty much all of the N-P-K is water soluable. Dig it into your garden and after the first heavy rain it is gone, and unfortunately winds up in a river or stream. I managed a chemical fertilizer plant here in NJ for a few years so trust me, I know exactly how it's made. If it is a true granulated fertilizer it is made from things like anhydrous ammonia, sulphuric acid, phosphoric acid, triple superphosphate, ammonium sulphate, potassium chloride, etc. If it is a blended fertilizer just look at the ingredients on a box of Miracle Grow, pretty much the same. That is why if you dug the chemical fertilizer into the potting mix it would surely kill all your plants and striping it on the soil surface basically turns it into a slow release fertilizer which an organic fertilizer is naturally.
I'll keep mixing my 3 cups of 5-3-3 100% organic into the soil before planting. It's worked beautifully for me so why should I stop. With the strangeness of dealing with Earthbox this year for reasons I can't quite fathom, I strongly suspect that what you read in that message thread is either misinformation or a total lack thereof.
Rich
Thank you Rich. I didn't do too bad mixing 3 cups of organic fertilizer in the potting mix last summer, so I figured I would continue to do so but I wanted to see if I would do even better by putting the fertilizer on top (which didn't really make sense to me because although I don't know much about gardening, I knew organic fertilizer was very different from the chemical kind).
I will keep on mixing in the organic fertilizer into the potting soil.
tmm
I experimented with organic versus chemical fertilizer this year. So far the organic is not living up to the chemical. In fact, I added a stripe of chemical today to green up those plants. Perhaps the organic I buy at the nursery is not as good as what you are using Rich. I will try something else in the fall season.
Exactly what are you using Graydawn? I've been mixing 3 cups of Espoma 5-3-3 100% Organic into the soil in each EB before planting for 4 years now and couldn't be happier with the results. Very surprised of your problem.
Rich