British Columbia: Onion problem ?

I grew my onions from seed in my greenhouse, starting in Feb. They grew well. I transplanted outside a month ago and I find some of the older leaves (there are typically three leaves) going yellow/brown in some plants. They haven't taken off like I thought they would. I've added pelleted fertilizer because it could be N. I could send a photo. Any suggestions ?

Tony

 

Take a look at the whole root. If the wire worms or white fly maggots have infested your garden from previous plantings, perhaps this is one cause… without pulling a few out of the ground and inspecting the whole plant, not sure what your alliums experiencing..

 

Thank you K. Baron, I appreciate your suggestions. Searching for information on the dreaded wire worms you described, I found a site from the Ontario Ministry of Agriculture on Managing Wire Worms in Vegetable Crops (http://www.omafra.gov.on.ca/english/crops/facts/00-047.htm). This site seems to suggest that onions are not susceptible to wire worms ......"Rotations with non-host crops such as onions, lettuce, alfalfa, sunflowers and buckwheat will reduce wireworm populations." Any further information on this topic would be appreciated.