Onion sets are an excellent choice for gardeners looking for a hassle-free way to grow delicious onions. By planting these small, dormant bulbs, you’ll skip the slow and finicky germination stage, giving you a head start on the growing season. With proper care and attention, you’ll be enjoying full-sized bulbs by midsummer. But what sets onion sets apart from seeds, and how do you get the best results from these convenient little bulbs?
Choosing the Right Onion Sets
When selecting onion sets, it’s essential to choose bulbs on the smaller side. This is because larger sets are more likely to bolt, which means they’ll go to seed instead of producing a full-sized bulb. In fact, sets smaller than three-quarters of an inch in diameter tend to produce the best full-sized bulbs. If you’re not careful, this can lead to disappointment in your harvest.
Understanding Onion Varieties
Onion sets are usually sold by color rather than by named cultivar, which means you have fewer choices in terms of variety. This can be a trade-off, especially if you’re looking for a specific type of onion. Seeds, on the other hand, give you more options and allow you to choose from a wider range of varieties. However, seeds require more care and attention, including the slow and finicky germination stage that onion sets skip.
Preparing the Soil
Onions need fertile, well-drained soil with plenty of organic matter to thrive. They don’t compete well with weeds or compacted ground, so it’s essential to prepare the soil before planting. One simple way to improve fertility and drainage is to work compost into the top several inches of soil before planting. This is especially important in heavier clay soils where onions tend to struggle. A slightly acidic to neutral pH is ideal, and onions are sensitive to acidity. If you’ve never tested your soil, this is a crop where it’s worth doing.
Soil pH and Onion Performance
According to the National Onion Association, a simple amendment can make a massive difference in performance later on. With the right soil pH, onions can grow larger and more flavorful, making them a staple in many gardens. In fact, soil pH can affect onion bulb size and quality, with optimal growth occurring between 6.0 and 7.0. So, if you’re looking to grow the best onions possible, make sure to test your soil and adjust the pH accordingly.
Planting Onion Sets
Planting onion sets is a straightforward process that requires some basic care and attention. First, select a spot that gets full sun, as onions need at least six hours of direct light per day. A shaded spot won’t produce the foliage growth the plant needs to build large bulbs. Next, push each set into the soil pointed end up, about an inch deep. Space them four inches apart if you want full-sized bulbs, or plant them closer (about two inches apart) if you’d like to harvest some early along the way.
Watering and Weeding
Onions have shallow root systems, which means they can’t pull moisture from deep in the soil the way crops like tomatoes can. They need consistent water, about an inch per week, to produce full-sized bulbs. Inconsistent watering leads to smaller bulbs and can cause splitting. Weeding is just as important, as weeds have an easy time establishing themselves in an onion bed. Pull them while they’re small, and hand-pulling is usually the safer option, especially once the bulbs start to swell. A thin layer of mulch (straw or shredded leaves) helps with both moisture retention and weed suppression, but keep it light.
Harvesting Onion Sets
When the tops of the onion plants begin to yellow and flop over, it’s time to harvest. Pull the bulbs, and let them sit in dry soil for a few days to start the curing process. This helps the outer skin toughen up for storage. Once the necks are completely dry and papery, trim the tops and move them into storage. Handle them gently, as even a small bruise can lead to rot over time. Well-cured onions stored in a cool, dry place with good air circulation should keep for several months, depending on the variety.
Long-Term Storage of Onion Sets
Onion sets grown as yellow storage onions tend to last the longest, with some varieties keeping for up to nine months. Red varieties, on the other hand, are best used within a few weeks. To keep your onion sets fresh for as long as possible, make sure to store them in a cool, dry place with good air circulation. Avoid storing them in a humid environment, as this can lead to rot and spoilage.
Conclusion
Planting onion sets is a great way to grow delicious onions with minimal fuss. By following these tips and guidelines, you’ll be enjoying full-sized bulbs by midsummer. Remember to choose the right onion sets, prepare the soil, plant them correctly, and harvest them at the right time. With proper care and attention, your onion sets will provide you with a bountiful harvest for months to come.
