Most any of the liquid supplements work well, both organic and synthetic. You could even use Miracle Grow if so inclined. Otherwise there are numerous brands of liquid supplements: Planet Natural fish emulsion or seaweed and fish blends, MaxiGrow, Fox Farm, BioThrive, Worms Way, Earth Juice, Gordons, just to name a few. And of course there is always compost tea (well strained).

Dave

Do you think a 20-0-0 is about right? I was looking at some of the fish emulsion types that are around 5-1-1 which is great but the price per gallon seems rather high compared to synthetic fertilizers.

Thanks for the info!

I think it's important to "band" fertilizer about 4 inches below the surface, in a trench, before onions are set out. I use a couple of inches of compost enriched with a balanced organic fertilizer and some wood ashes. This way the fertilizer is ready for uptake in late spring, when soil temps warm and the plants are growing rapidly. I may give them a liquid drench in June, but otherwise depend on the soil-incorporated fertilizer. Ideally, the plants will use it up just before they mature. This is the fertilizer curve used by commercial onion growers, and it works well in my organic garden too.

Instead of using plastic mulch, I interplant onions with leafy greens (lettuce, arugula, etc). The greens are ready to pull out just when the onions need the space, and meanwhile they smother weeds.

Drip irrigation (aka fertigation) is a very different approach than banding granular fertilizers. Just as good IMO when properly done but a totally different approach.

Do you think a 20-0-0 is about right? I was looking at some of the fish emulsion types that are around 5-1-1 which is great but the price per gallon seems rather high compared to synthetic fertilizers.

No 20-0-0 is far too unbalanced for use in properly done fertigation. Fertigation is defined as frequent low-dose feeding. Frequent as in everytime you water. The goal is to supply a consistent low-dose of nutrients to the plants, NOT to over-dose the plants every now and then as 20-0-0 would do.

Price is something personal you will have to work out. I find most of the liquids to be comparably priced since they are used in such small amounts that a little goes a long way.

JMO

Dave

Thanks for the info, Dave and planatus. I am pretty new to drip irrigation. In the past I've done a pretty conventional garden with over head watering. But in light of last years bad drought, I wanted to try and conserve as much water as possible so I thought drip irrigation would be just right.

Is it okay to "band" fertilizer and apply low frequent dosing of a low Nitrogen fertilizer? My plan was to apply 10-20-10 similar to banding before planting my bunches and then setting up the drip irrigation that allows me to feed them nitrogen during the growing season.

Thanks again for the info. I'm not new to gardening but I am relatively new to applying specific fertilizers to plants in drip irrigation. Thanks!