Planting onion sets in the spring is a great way to both enjoy an earlier harvest, and bigger onions from your garden.
Onions can be planted with bulbs (sets), transplants, or by seed. Although seed is the least expensive way to plant, spring seeds take a long time to germinate and grow.
In fact, so much time, that some long-season onion varieties have a lot of trouble reaching full maturity by fall. It can lead to a disappointingly small harvest when planting seed onions in the spring.
It’s not that growing onions from seed is a bad idea. In fact, many gardeners grow onions quite successfully with seed in the fall. Fall seeding allows time for the onions to become established before winter. Then, as spring returns, they can continue on to grow to full size by summer’s end.
Onion seeds can also work well in the spring for those who want to grow and harvest small green onions for fresh eating. (See : Growing Onion Sets Vs. Onion Sets)
But in most growing areas, there is simply not enough growing days to start onions in the spring from seed. Not at least if you are looking to grow sizable onions for harvesting.
Onion sets produce onions ready for harvest quickly compared to seed planting in the spring. As much as two, to two and a half months earlier.
And that is exactly why using sets vs. seed in the spring is so important!
Selecting Onion Sets For Growing
Onion sets can usually be found in most garden centers and feed stores in early spring. Although there are many varieties, almost all sets are sold simply as yellow, red, or white onions.
When selecting onion sets, don’t worry if the onions seem small. Smaller sets will produce large bulbs. In fact, if the bulbs used for sets are too large at planting, they often bolt before ever maturing. For that very reason, smaller bulbs are better.
How To Plant Onion Sets In The Spring
How you plant your onion set bulbs depends on what type of onions you want to harvest.
If you are looking to harvest large onion bulbs, plant bulbs approximately 1.5″ deep, and 3″ to 4″ apart. This space is vital to let spring planted onion sets have room to grow.
If you are, however, looking to grow spring onions from your sets (green onions), plant bulbs closer at 3/4″ apart. These onions can be harvested in as little as 4 weeks, and simply don’t need or require additional space.
Planting For Success – A Few Final Tips
Onions require loose, well-draining, and fertile soil to grow well. The loose soil helps onions to absorb moisture quickly. It also helps the onions to keep from rotting in overly damp conditions.
Mixing in generous amounts of compost at planting is one of the best way to provide good soil conditions for onions. Compost adds nutrients to the soil, and in addition, helps loosen the soil structure. Product Link : Uncle Charlies Bagged Compost
If you are growing in extremely hard soils, or soil that has a lot of clay, adding in a bit of sand will help with drainage as well.
Mulching & Fertilizing
Although onions don’t require additional nutrients in the form of fertilizers, keeping the crop mulched will help keep moisture in, and weeds out. And nothing will keep a crop of onions from reaching their full potential like competing weeds!
Mulch the soil with a few inches of straw or shredded leaves at planting time, and then add a few additional inches as the onions sprout and grow.
Here is to planting a few onion sets this spring for a great crop of summer onions this year!
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