I used to grow lovely baseball-sized onions. Starting from seed in the greenhouse, then planting outside after last frost date. I always rotate my crops (nothing ever planted in the same place before three years pass). For the past two years, the onions have been ping-pong sized. I plant with fertilizer, usually side-dress. I have other root crops that do fine - beets, potatoes, carrots. Any ideas on what's up with the onions?
Why were my onions small?
For bigger onions, space the transplants 4" apart and don't plant them too deep, they should only be planted deep enough for the roots to catch in the soil. For the northern half of the country, be sure you buy "long-day" varieties.
The variety i.e. long day or short day seems to be the most critical thing. Everything I have read says that. Down here in Florida, to get big bulbs, you have to buy and grow short day types or you will have failure.
BocaBob
Short day onions are great for winter growing. However if you can grow onions in June July and August, long day onions are the best. Short day onions need to ready for harvest in May at the latest. the Vidalia harvest starts in March, peaks in April and is finishing up when May arrives. If a southern location has good climatic conditions for summer growth ( high elevations for example) than long day onions would be appropriate. If you are catching the spring season or fall season than day neutrals are the cat's meow.
Farmerdill,
You know your stuff !!!!!!!!!!!!!!!!!!!!!!
BocaBob
Farmerdill,
You know your stuff !!!!!!!!!!!!!!!!!!!!!! Here's some Granex (short day ) growing on 5 gallon grow bags
BocaBob
and here is some younger ones
My suggestion is to set them out BEFORE the last frost date. They need that early cool weather.
Farmerdill, we can not grow long day plants this far south because we don't have long days in summer. Our day length doesn't vary very much all year long. We get daylight around 6:30 am and the sun sets around 7:00 in winter and 8:00 in summer. That is why we can't grow long day onions here.
I copied this from the Minnesota extension service website (they have a great instruction sheet for onions).
"The most important thing to remember when buying onion seed is day length, especially if you're ordering from a national mail order firm. In Minnesota, we need to buy "long day" onion seeds because our summer days can be 16 hours long.
In the south, day length varies less and averages about 12 hours of light per day. Onions for southern gardeners are "short day" onions. You can raise short day onions in Minnesota but they will bulb as soon as day length reaches 12 hours and you'll get small onions.
Long day varieties start to bulb when day lengths are about 14-16 hours. If you start onion seeds indoors, keep lights on only 12 hours each day to give the plants a suitable night. Onion seedlings will form bulbs too early if exposed to long days at any time during their development. You will not get anything bigger than sets. "
I haven't mastered onions yet. Sometimes I get good-sized ones even in a neglected row, other times I get none at all in a cared-for row. Scratching head....
Here is Vegmandan - he is in love with onions! If you have time, check out all the pics and how he ties up the onion for exhibition! I think the Brits really have it all over us when it comes to gardening; no offense. He grows Ailsae. Maybe there's some tips there for ya.
http://www.allotment-diary.co.uk/page3.html