I get mine at the local "greenhouse", in those small bags.....and yes, it IS expensive...I always order the "Triple Super Phosphate", which is 0-45-0, and his "selling price" is $7.95.....but he gets it for me at $6. I usually get 6 bags at a time. I just finished the "spring" application", on all the iris......some get "straight 0-45-0, as they are getting their nitrogen 'boost from the alfalfa, and corn gluten meal, and some get the 10-10-10 X 0-45-0 mix.......the rebloomers will get a "summer dose", as well. I have used 4 of the 6 sacks (and actually may have a small amount left in one of the bags), to do ALL my beds, PLUS some of Rita's Daylilies. That's 2860 square feet of iris beds (nearly 800 'plants") plus about 30 daylilies (still have more of them to do). Application rate is 'about " a teaspoon to a tablespoon full per plant....depending on the size of the clump...and, in fact, the really small plants are probably not getting that much. We do have fertilizer plant, 2 blocks away, and I COULD probably get a wheelbarrow load of phosphate for the "bribe 'of a cold 6-pack....but it's "Straight stuff"...no fillers added yet, and mixing would be much harder to regulate, and, it's VERY corrosive, and hard to store without it drawing moisture, so, I would rather just but the bags.
You have to remember, this stuff is STRONG, even cut 50% with the 10-10-10.....you don't need very much !
