Onions are one of the easiest plants to plant. Similar to planting potatoes, they require minimal care and no pruning once planted. They can also be stored long term and used in a variety of meals. If you want to start a garden, onions are one of the best places to start. Keep reading to find out all about planting onions!
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Types of Onions to Plant
This year, I planted red, yellow, and white onions. I have also planted shallots in the past. You can plant onion sets, onion starts, or plant from seed. Onion sets look like a small onion bulb and will produce a small table onion. They are dormant onion bulbs that were started the previous year.
Starting onions from seed can take a long time, so another option is to buy onion starts (or transplants) which have a bulb and some greenery. They produce larger onions–many of which can be stored long term. These were grown the year before and usually come in bundles of 50-75 onions.
If you plan to store your onions long term, look for a storage variety. You also need to consider if you should grow short-day or long-day onions. Short-day onions require 10 hours of sunlight each day, while long-day onions require about 15 hours. Make sure you check to see if the onion you want to grow is compatible with your region.
Storage Onions
The following onion varieties are recommended for long-term storage according to the blog, The Spruce Eats:
Yellow Onions
- Bridger
- Copra
- Cortland
- Patterson
- Pontiac
- Talon
- Yellow Globe (includes heirloom and hybrid varieties)
- Yellow Sweet Spanish
White Onions
- Southport White Globe (heirloom)
- Stuttgarter (heirloom)
- White Sweet Spanish
Red Onions
- Brunswick (heirloom)
- Red Bull
- Red Creole (heirloom) (short-day)
- Red Wind
When to Plant Onions
If starting from seed, most onions must be started 10-12 weeks before your zone’s last frost date. Check the seed packet to make sure prior to planting.
Onion sets can be planted as soon as the soil is no longer frozen and can be worked. This is usually in late March or early April.
Onion starts or transplants should be planted 4 to 6 weeks before the last frost in your zone.
How to Prep the Soil for Planting Onions
Onions need a good fertilizer to help them grow. Use a nitrogen-based fertilizer and work it into the soil prior to planting. I used bone meal for my onions, but you could use a different one high in nitrogen.
How to Plant Onions
For onion sets, simply space the onions out 2-6 inches apart. Then, push them 2 inches deep into the soil. If you plant the onions closer together, you will get smaller bulbs that can be pulled early as scallions.
For transplants, space each plant 5 inches apart with rows 12-18 inches apart. Push the bulb in about 2 inches, packing the soil firmly around the base of the greens.
How to Care for Onions
Once planted, cover the onions with a light mulch such as straw or dead leaves to help with weed control. Fertilize the onions every 3-4 weeks with a nitrogen-rich fertilizer. Stop fertilizing when the bulbs become visible on the surface.
Onions do not require a significant amount of water, but it is good to water them extra during extreme heat to prevent them from bolting early (going to seed which will stop growth).
We use a drip line system, but we water them with a hose until they are more established.
When to Harvest Onions
You will know that your onions are ready to harvest when the green tops turn brown and fall over. Harvest spring-planted bulbs in late summer. Reduce watering a few days before gently pulling the onions so that they will store longer.
Onion Recipes to Try
Wondering what to do with all of those onions once you grow them? Here’s some highly-rated recipes to try!
- French Onion Soup
- Salsa
- French Onion Grilled Cheese Sandwiches
- Caramelized Onion Burger
- Onion Tart with Bacon
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