NYEric
Well-Known Member
Some Phrags I bought had little pale beads in the media. A slow release feed I assume. Anyone know of problems using Osmacote in slippers?
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At some point I read on here a grower burning their roots and advising toward Nuticote instead. I used Florikan but probably over dosed and under flushed and ended up losing some plants and severely weakening others.
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That business about fertilizer burn is an indication of improper choice and/or improper use of any such product.
They’re all just ordinary fertilizer encapsulated in a porous polymer. Once water has entered the pellets, the solution starts to seep out.
The polymers have engineered porosity and thermal expansions that control the seepage rate. The higher the temperature, the faster the rate. So…
If you use a product designed to last 9 months, figuring it’ll dwindle by winter, that’s great, but if that product is designed to last 9 months at an average media temperature of 70F, and your greenhouse runs in the 80’s and 90’s in the summer, those pellets will be dumping a lot more fertilizer then than you may have accounted for.
The alternatives are to use less of that one, knowing it’s going to “overproduce” in the summer, or use one that has a more appropriate release rate at the expected temperature.
I have played a bit with an Osmocote product that has an 8-9 month life @ 70, but only 5-6 months @ 90, which is common in summer here. It is putting out 50% more fertilizer at that temp, so I reduce the amount accordingly.
I have decided that I prefer the “known” method of applying a specific concentration of water-soluble fertilizer on a schedule over using the pellets, so the pellets are only used on my annuals and perennials, tomatoes, figs, and herbs.
They’re all just ordinary fertilizer encapsulated in a porous polymer. Once water has entered the pellets, the solution starts to seep out.
The polymers have engineered porosity and thermal expansions that control the seepage rate. The higher the temperature, the faster the rate. So…
If you use a product designed to last 9 months, figuring it’ll dwindle by winter, that’s great, but if that product is designed to last 9 months at an average media temperature of 70F, and your greenhouse runs in the 80’s and 90’s in the summer, those pellets will be dumping a lot more fertilizer then than you may have accounted for.
The alternatives are to use less of that one, knowing it’s going to “overproduce” in the summer, or use one that has a more appropriate release rate at the expected temperature.
I have played a bit with an Osmocote product that has an 8-9 month life @ 70, but only 5-6 months @ 90, which is common in summer here. It is putting out 50% more fertilizer at that temp, so I reduce the amount accordingly.
I have decided that I prefer the “known” method of applying a specific concentration of water-soluble fertilizer on a schedule over using the pellets, so the pellets are only used on my annuals and perennials, tomatoes, figs, and herbs.
NYEric
Well-Known Member
Ray, I think we underfeed so I'm using it as an additive. Not too much per plant. Thanks.
That is exactly how some larger-scale growers I’ve talked to used it- a small amount to provide a longer-term “baseline feed”, with periodic doses of water-soluble ferts to supplement it.
