Marianne's Response
Osmocote in the DEEP South
Marianne,
We live in Mobile, AL, the wettest city in the continental US. (Don’t believe what Seattle says.
Our weather conditions from the middle of May through the end of September are 90 degrees + during the day; unbearable humidity and lots of thunderstorms. Night temperatures typically are in the upper 70s with continued humidity. Summers are no fun at all…..but then there are the other 7 months. We already have hydrangeas and tons of salvia in bloom.
Now for my concerns. Osmocote is temperature and moisture activated. (Correct?)
1 With our conditions, should I not add additional fertilizer in 2 months vs the directed 4 months?
2 As conditions may result in a more rapid release of nutrients, should I not reduce the application amount. (I use Osmocote on shrubs and in reduced amounts on flowers as I also use Peters Bloom Booster water soluble on a 7-10 day schedule.
3. I mulch with pine straw and shredded cyprus. With the retention of moisture under the mulch (Which may increase the release rate ?), would it not be best to sprinkle the Osmocote on top of the mulch and let the nutrients filter through or scratched in on the surface of the ground under the plant’s drip zone?
Thanks so much for your help.
Sincerely yours,
Dave Snyder
Posted by David Snyder on May 1, 2018
Marianne's Response
- I recommend sticking with the directions on the label. The 4-month or 6-month claims assume the SOIL temperature is a constant 70 degrees for the entire period. Remember, it's the soil temperature that matters, not the ambient temperature (air). Soil temperatures change gradually, up or down, depending upon sunlight and ambient temperatures.
- Osmocote is formulated to provide a safety factor of 3x. In fact, horticulturalists at the company say it is even greater than that. What does that mean? It means you have to over-apply at 3-times the recommended amount to create even the first stage of a problem. You are unlikely to get into trouble sticking to the recommended application amounts, regardless of local circumstances.
- Osmocote feeds via a plant's root system (not foliar as with a water-soluble plant food -- foliar means through the leaves). One of the coolest features of Osmocote is that the release of nutrients is done by osmosis. That's a natural process that keeps the supply of nutrients equal on both sides of an Osmocote granule's coating. Nutrition flows from the Osmocote granule into the plant's root system at the same rate as the plant is taking it up to the stems and leaves. It's kind of like a chain of ball bearings, the first can't move any faster than the last. Pretty slick, huh?
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