Miracle-Gro® Water Soluble Azalea, Camellia, Rhododendron Plant Food
A product like this will work fine.. Make sure you dilute it 2-4 times more than the recommended dosage. You want a HIGH nitrogen fertilizer.
Make sure your water has a PH of 6.5-7.0 or else your plants will not be able to absorb the NUTRIENTS..
and NOW you KNOWM