ed:

Once a month ammonium sulfate or a little Osmocote is enough if they are growing fast enough. Mine are actually growing too fast after they get some size so I'm trying to slow them down. I may cut off fertilizer for several months on the plants more than a year old.

My Sweetcrisp in a 10 gal pot that I've had 22 months is 5ft tall and almost as wide. It could have 8-10 lbs fruit this year. I've already applied a little Osmocote. That may be all it gets all year.

How did yours grow last year?

fruitnut - what type of Osmocote are you using?
I scoured the web for what you have previously called Osmocote for Acid Loving Plants or Osmocote for Azaleas...
but it appears they have re-packaged. Even the main Osmocote website did not have anything like that.

They grew well. I have a 4yo BlueCrop, and a 3yo Blueray. My container mix is very fast draining, so I think that alot of my liquid fertilizer leeched through. I'll probably repot this year and use a little more of a moisture retaining mix & possibly a little granular slow-release fertilizer. Here's a link to photos of them last fall.

http://forums2.gardenweb.com/forums/load/fruit/msg0810090612460.html

Miracle-Gro Shake 'n Feed Tomato, Fruit and Vegetable Plant Food. Works great.

Consider Espoma Holly Tone.

• An all natural plant food specifically formulated for all acid-loving plants
• Long lasting, slow release feeding
• Complex blend of of the safest, finest natural ingredients available
• No sludges, fillers, or toxic ingredients are ever used

Save the organics for the garden where the soil can break them down. Not the best for containers.