tart to see real growth from your spring bulbs – narcissus, tulips, etc. – you can transplant your baby onions out to the garden (see section on onion plant starts for transplant details).
Onions From Sets
- Advantages: easy
- Disadvantages: extremely limited variety, occasionally unreliable bulbing or storage qualities
Sets are a common sight in the nursery every spring. They look like tiny, cured onion bulbs, with the papery brown skin and everything. Typically you’ll see them corralled small, plastic mesh bags that allow for good airflow. They might be labelled, “red,” “yellow,” or “white” with no additional varietal information given.
Planting onion sets is as easy as it gets. Wait until your local nursery is selling them, take them home, and shove them root-side down and pointy-side up into damp earth until the pointy bit is just a bit below the soil level. Wait.
For best results, sort through your sets a bit as you plant. Try to plant mostly uniform, regular-size elongated sets. These are most likely to successfully form a nice, globe-shaped onion. Sometimes you’ll get big, oversize jumbo sets. Bigger isn’t always better – and this is one of those cases. Dramatically larger-than-average sets are more likely to bolt instead of sizing up.
Spacing your sets 4-inches apart or a bit more will allow them to grow into nice size bulbs. Plant 2-inches apart or even closer if you want to yank every-other-plant as they grow to use as green or spring onions.
Onions From Plant Starts
- Advantages: easy, reliable
- Disadvantages: expensive, somewhat limited variety
My favorite easy option for a bountiful onion patch is starting with onion plants. Onion plants look like trimmed up, thin green onions. They are the freshly dug onion plants, just like what you would grow from same-year seed, if you had the time and inclination to do so.
Dried slightly to send the plants into dormancy but still very much alive, typically they are sold in bundles of 50 or so onion plants, all of the same variety. Prices generally range from around $10 if you can find conventionally grown bundled plants locally, to around $20 if you order in organic plants from a specialty retailer and pay shipping.
When your onion plants arrive, remove them from the shipping box, seperate them gently, and keep them in a cool, well ventilated place until you can transplant them into your garden. Unless the package instructions tell you otherwise, don’t soak your onion plants or anything.
Plan to transplant your onions promptly once they arrive to you. I’ve gotten distracted around the time my onion plants arrived and neglected to plant them for a few weeks. They will survive such neglect – but that kind of trauma sucks resources from your baby plant that would otherwise go into rapid early-season growth.
Larger onion plants will grow into larger onions. Prioritize planting the thickest, stockist looking plants. To transplant, amend and loosen your soil, then plant the onions about 1-inch deep, just below the point where the white part of the onion changes to green. Firm and water the onion plant in, and give it a gentle little tug to make sure it’s standing up nice and tall in the soil.
As with sets, space your onion plants about 4-inches apart for full size bulbs, or about 2″ apart if you plan to thin and eat the thinning as spring onion. For massive onions (especially if growing large types like Walla Walla) wider spacing is appropriate.
What’s your best tip for growing top quality onions?28