Can I use 5-gallon grow bags for growing Tomatoes

Q. Would it be ill-advised to try and grow tomatoes in a greenhouse in 5 gallon grow bags using sawdust and sand as a growing medium? Other than the difficulties watering, is there anything else that might hamper productivity? I can purchase 500 bags for $80 and to put in wood sided grow beds is cost prohibitive at this point.

A. What you describe has been and continues to be used successfully to grow tomatoes in greenhouses. Usually, however, the fertilizer is in the water, and the watering system is at least semi-automatic.

Consider automating your watering system somehow, and putting your fertilizer in the water. 5-gallon buckets will not be as forgiving of long intervals between watering as are Grow-Boxes.

In using the Mittleider Magic fertilizers you will need to dissolve the fertilizers in water for a day, then pass them through a very fine screen, so that the un-dissolved carrying agents don't clog your watering system, if you're using emitters, or any system with very small holes.