Hi Mdgardengurl,

I am also in zone 7, near the coast in central NJ, and I plant around April 1st with good success.

Dixondale Farms has established onion plant ship dates by Zip Code (http://www.dixondalefarms.com/shipping) and they show April 7th as their standard ship date for Maryland. They show the same date for NJ, but I requested an earlier ship date. Dixondale also has an onion planting guide that may be helpful (http://www.dixondalefarms.com/downloads/OnionPlantingGuide.pdf)

For good size onions, the right variety is very important. Maryland is right around the border for Long Day varieties and Intermediate Day varieties, so either should work well. I suggest Candy and Walla Walla as nice large onions for your area. Give them a good shot of nitrogen in the early spring to get the top growth going.

TomNJ

Tom, thanks so much for that information! I just downloaded their guide, so will study it today, and place my order with them tomorrow morning.
Thaks again!

ask and ye shall receive

Here is a link that might be useful: Planting dates for MD Zone 7