As a child, I was frequently asked to help my parents in the garden. At a young age I didn’t enjoy working in the garden, but I did enjoy picking the produce. As an adult I have grown a garden each summer over the last 5 years. I definitely had a head start because of my childhood experiences, but I struggled the first 4 years growing onions.
I have been planting onion sets which are the dried onion bulbs. I guess I just assumed that the onion seeds (sets) were the correct way to grown onions. It turns out that I was wrong. Most greenhouses and seed catalogs also sell onion plants in bunches. These are small onion plants with roots and green tops. I can’t speak for other areas of the country, but in North Dakota it is imperative that you start with onion plants rather than sets if you want to grow big onions. Onion sets will also grow onions, but they will be much smaller at harvest time.
One thing to keep in mind when buying onions are that certain varieties will do better in your area. If you are buying onion plants from a local greenhouse you will most likely get a correct variety. If you are ordering from a seed catalog, make sure that you order a variety that will grow in your area. The onion bulb formation is triggered by the length of the daylight hours. In the southern U.S. the growing season occurs in the winter when the days are short. In the northern U.S. the growing season occurs during the summer when the days are at their longest points. Living in North Dakota, I need to buy “long day” onions if I want them to grow big.
This last summer I was finally successful in growing huge walla walla onions and big sweet Spanish onions. I did some reading and experimenting; here is what I did to grow some big delicious onions.
- Start with onion plants rather than onion sets (dried bulbs)
- Buy the correct onion varieties for your area
- Feed your onions with some type of fertilizer (shout out to my chickens!)
- Keep the ground moist, but not wet and do not let dry out
- Give the bulbs adequate spacing; approximately 4 inches is enough
- Keep the weeds away from your onions
- Eat the walla walla onions quickly since they don’t store very well