Here, I fertilize with every watering, every two days sometimes in the summer. I use 1/5 to 1/7 the manufacturer's recommended amount, and I drench the plants and the medium so that water is literally pouring out the bottom of a pot before I move on to the next one. If your plants are all in S/H, make sure you're actually flushing the reservoir out each time you water. If you're only topping up the reservoir to where water just begins to flow out the holes, you're only going to be making up for water loss due to evaporation, and evaporation will leave fertilizer salts in the reservoir. Those will just accumulate each time you water / fertilize unless you flush the pots really well.
I don't use Dyna-Gro so I don't know what the dilution factor is on that, but if the cause of the browning actually is fertilizer burn, flushing the pots when you water, watering with plain water in between fertilizations, and using less fertilizer each time will all help curb the problem.