I was VERY happy with the results I got with Osmocote Slow Release 15-9-12 Fertilizer last year on my fruit trees, plants and veggies. I did need to supplement the calcium via bonemeal but other than that it worked phenomenally with only two applications.
I’ve been shopping around for buying it in bulk but it looks like the bulk prices aren’t that much better than the 8lb bag prices. Most places online sell a 50# bag for $100 + ~$25 shipping = $2.55/lb but I can just buy it on Amazon where it dips down to $19 for a 8# bag = $2.38/lb.
Osmocote surely isn’t the only slow release product on the market? Maybe I should be looking for local places that may carry it?
AMAZON PROTIP: Get a price tracking extension like Keepa to watch for price drops of things you know you will need to buy in the future (supplies, tools, etc.).
EDIT: I went ahead and created a spreadsheet comparing different sow release fertilizers on the market in this comment here
The best is Dynamite. Plants in general require a 3-1-2 NPK ratio. Of course not all, but as a general fertilizer that is a great number. You will notice Foliage pro has that ratio. One of the best, if not the best soluble fertilizer.
Free shipping for the 9 month Dynamite slow release. I wish I could get this is bulk too. But 2 bags is enough for me all season.
Since I have all my veggies on drip irrigation my plan was to also inject a low dose of water soluble nutrients every time I water. The big problem with water soluble nutrients is they just completely wash away the first time you water or it rains if you have well draining soil.
Dynamite also has all the micros, but lasts longer than Osmocote. Dynamite used to be only distributed to commercial nurseries. Only in the last few years they went retail too. So sources for wholesale must be out there.
What are you using it for- soil or containers? I only use complete fertilizers in conjunction with container growing. In good soil, most often all that plants respond to is nitrogen, especially if you are also using mulch and/or compost.
For soil grown trees I buy slow release encapsulated urea for a fraction of the price of Osmocote that I buy by hundreds of pounds from an agricultural supplier- 50%N 90 day release that runs about 25 cents a pound, I think.
Around here it is used primarily by corn growers, but if you want to stimulate growth of fruit trees it works great for that. Generally, I wouldn’t want much longer release than that- no point in stimulating vegetative growth into fall.
For established trees a quick release app of N is probably best- applied at first signs of growth. That is to provide growth to the spur leaves and fruit in its earliest stages of growth when size is being increased by cell division and not by expanding the size of individual cells. Later in the season too much water and N just leads to bigger but blander fruit by encouraging larger cells, but more cells means higher brix.
For anyone reading this FYI the free shipping code until the 16th on amleo.com is 1C19PW and not 1C18PW like it says on their home page right now. Just picked up a bag of Florikan 4-5 month 18-5-12 Controlled Release Fertilizer