I remember reading somewhere that plant food that uses urea to suppy
nitrogen is bad for orchids but I can't find that literature any more. Can
anyone confirm this or is my memory just playing tricks on me?

Thanks,

Peter

Peter Nigra wrote:

I remember reading somewhere that plant food that uses urea to suppy
nitrogen is bad for orchids but I can't find that literature any more. Can
anyone confirm this or is my memory just playing tricks on me?

Thanks,


That is a question sure to invoke a variety of heated responses.
Short answer (in my opinion). Urea not bad. But, urea probably not
best, either. You won't kill your orchids fertilizing with a urea based
fertilizer. They may not be getting quite as much nitrogen as you
intend. Short reason is that urea is typically broken down into plant
munchable bits by soil bacteria. You have few soil bacteria in your
potting mix. So, the prevailing wisdom is that since plants can't
utilize urea directly, you are wasting your time fertilizing with it.

That said, it isn't at all true. You can grow good orchids with a
urea based fertilizer. But you have to use a lot more nitrogen to get
the same result. Most of the people I know have switched to non-urea
based fertilizers for that reason, but any fertilizer is better than no
fertilizer. So, don't worry about killing your plants with the urea,
but you may want to consider switching at some point.

Rob

--
Rob's Rules: http://www.msu.edu/~halgren
1) There is always room for one more orchid
2) There is always room for two more orchids
2a. See rule 1
3) When one has insufficient credit to purchase
more orchids, obtain more credit

Let me first emphasize Rob's point that urea is not actively harmful to your
plants; at worst, relying on it as fertilizer may result in a nitrogen
shortage in the long-term. So I wouldn't say that it is "bad"; the question
is whether it does any "good." There are lots of folks out there growing
perfectly fine orchids with Peter's 20-20-20, which gets most of its
nitrogen from urea; and more than a few who are satisfied with their
orchids' performance with no fertilizer at all.

As to whether urea is beneficial or not, I've seen conflicting research. I
suspect [but do not know for sure] that the potting medium has much to do
with this. It seems likely to me that denser mixes [esp. something like
Pro-Mix] might hold the urea long enough for it to become useable by the
plant, whereas chunkier, more open mixes would not [assuming it has to hang
around to become useable, a point which I tend to believe but don't accept
as definitely "proven"]. Also, some media [most notably bark] are reputed
to "rob" nitrogen from the plants, which could exacerbate the problem.
Finally, the method of fertilizing [pot only vs. foliar spraying] might make
a difference in the results [another point on which there is conflicting
research].

All that said: We spray our fertilizer through the sprinklers, which
results in both foliar and in-pot feeding, and currently use Dyna-Grow,
which does not rely on urea for its nitrogen. This works well for us --
your mileage may vary G.

Good growing,

--
Kenni Judd
Juno Beach Orchids

http://www.jborchids.com
"Rob Halgren" wrote in message
...
Peter Nigra wrote:

I remember reading somewhere that plant food that uses urea to suppy
nitrogen is bad for orchids but I can't find that literature any more.
Can
anyone confirm this or is my memory just playing tricks on me?

Thanks,


That is a question sure to invoke a variety of heated responses.
Short answer (in my opinion). Urea not bad. But, urea probably not
best, either. You won't kill your orchids fertilizing with a urea based
fertilizer. They may not be getting quite as much nitrogen as you
intend. Short reason is that urea is typically broken down into plant
munchable bits by soil bacteria. You have few soil bacteria in your
potting mix. So, the prevailing wisdom is that since plants can't
utilize urea directly, you are wasting your time fertilizing with it.

That said, it isn't at all true. You can grow good orchids with a
urea based fertilizer. But you have to use a lot more nitrogen to get
the same result. Most of the people I know have switched to non-urea
based fertilizers for that reason, but any fertilizer is better than no
fertilizer. So, don't worry about killing your plants with the urea,
but you may want to consider switching at some point.

Rob

--
Rob's Rules: http://www.msu.edu/~halgren
1) There is always room for one more orchid
2) There is always room for two more orchids
2a. See rule 1
3) When one has insufficient credit to purchase
more orchids, obtain more credit

Let me first emphasize Rob's point that urea is not actively harmful to your
plants; at worst, relying on it as fertilizer may result in a nitrogen
shortage in the long-term. So I wouldn't say that it is "bad"; the question
is whether it does any "good." There are lots of folks out there growing
perfectly fine orchids with Peter's 20-20-20, which gets most of its
nitrogen from urea; and more than a few who are satisfied with their
orchids' performance with no fertilizer at all.

As to whether urea is beneficial or not, I've seen conflicting research. I
suspect [but do not know for sure] that the potting medium has much to do
with this. It seems likely to me that denser mixes [esp. something like
Pro-Mix] might hold the urea long enough for it to become useable by the
plant, whereas chunkier, more open mixes would not [assuming it has to hang
around to become useable, a point which I tend to believe but don't accept
as definitely "proven"]. Also, some media [most notably bark] are reputed
to "rob" nitrogen from the plants, which could exacerbate the problem.
Finally, the method of fertilizing [pot only vs. foliar spraying] might make
a difference in the results [another point on which there is conflicting
research].

All that said: We spray our fertilizer through the sprinklers, which
results in both foliar and in-pot feeding, and currently use Dyna-Grow,
which does not rely on urea for its nitrogen. This works well for us --
your mileage may vary G.

Good growing,

--
Kenni Judd
Juno Beach Orchids

http://www.jborchids.com
"Rob Halgren" wrote in message
...
Peter Nigra wrote:

I remember reading somewhere that plant food that uses urea to suppy
nitrogen is bad for orchids but I can't find that literature any more.
Can
anyone confirm this or is my memory just playing tricks on me?

Thanks,


That is a question sure to invoke a variety of heated responses.
Short answer (in my opinion). Urea not bad. But, urea probably not
best, either. You won't kill your orchids fertilizing with a urea based
fertilizer. They may not be getting quite as much nitrogen as you
intend. Short reason is that urea is typically broken down into plant
munchable bits by soil bacteria. You have few soil bacteria in your
potting mix. So, the prevailing wisdom is that since plants can't
utilize urea directly, you are wasting your time fertilizing with it.

That said, it isn't at all true. You can grow good orchids with a
urea based fertilizer. But you have to use a lot more nitrogen to get
the same result. Most of the people I know have switched to non-urea
based fertilizers for that reason, but any fertilizer is better than no
fertilizer. So, don't worry about killing your plants with the urea,
but you may want to consider switching at some point.

Rob

--
Rob's Rules: http://www.msu.edu/~halgren
1) There is always room for one more orchid
2) There is always room for two more orchids
2a. See rule 1
3) When one has insufficient credit to purchase
more orchids, obtain more credit