If it's still green (or yellowish but still alive and not brown and heading for dormancy) it'll work.

Even if it doesn't, it just washes in and adds a tiny bit more iron to your soil. No harm done, ferrous sulfate is not a major water pollutant to my knowledge.

Thanks Morph.....it's still green but would like it greener. Worth a shot,like you said

where did you find liquid iron this time of year in New Jersey?