Too much phosphate?

[wysiwyg]

I found some pelletized triple superphosphate while cleaning the garage and decided to put it around some of my new trees. I looked up applications rates on google and skimmed through a document for Christmas tree growers that said 2.1 oz per tree as maintenence. However, without further investigation I spread those 2.1 oz right around the drip line (about a 2 ft circle) and worked it into the mulch (but not into the soil). 2.1 oz doesn't seem like alot....but I was just reading through that document again and missed the little detail that the 2.1 oz was to be spread over a 6x8 ft area. Big whoops!!

What I haven't been able to find is, what are the effects of too much phosphate? Is it possible to poison the tree with phospates, or do they only use what they need? and should I dispose of that mulch that I mixed the TSP into??

 

[Ekka]

Depends on the species of tree, what are they?

Also, the phosphates may burn, the foliage will red/brown off. But I seriously doubt the amount you put on will do that unless it's an Aussie native.

A lot of the Aussie natives are extremely sensative to phosphates and shouldn't be fertilized with them. They have a modified root system called proteoid root system which is highly efficient at extracting phosphorus, so any addition of P becomes toxic.

http://www.scottsaustralia.com.au/OSMOCOTE.HTM#os-native is a product formulated for our natives.

 

[LightningLoader]

I always figured that the plant would simply not absorb more phosphate than it needed. Phosphorous doesn't leach out of the soil like other minerals do, so many areas have phosphate off the charts from years of fertilizing, and it doesn't seem to hurt the plants.

Triple super phosphate is good stuff too. That's what we put on out lawn when we first laid sod, and it took root within like 3 days.

Husband who is fertilizer salesman claims that anything can reach a toxicity level, but that it differs according to the plant. If it's not to late, try to rake and spread out the topsoil maybe.

 

[wysiwyg]

Thanks for the replies! I took the precaution that same night to rake away the mulch and spread it in a much larger radius, and then gave each tree new mulch. There's a lot of grass in this area so hopefully that will absorb much of the excess phosphorus. Definitely won't make that mistake again!!