When To Plant Scallions Outside

You should plant scallions outside as soon as the soil can be worked in early spring, roughly 4 to 6 weeks before your last expected frost date.
 
This early planting window is perfect because scallions are incredibly cold-hardy and will happily tolerate light freezes and even a bit of snow.
 
If you’re wondering when to plant scallions outside for a fall harvest, you also have a fantastic second chance in late summer, usually about 8 to 10 weeks before your first fall frost.
 
Timing your scallion planting right is the single biggest secret to getting those crisp, mild green onions all season long.
 
In this post, we’ll break down exactly when to plant scallions outside, what soil temperatures they love, and how to keep a steady supply coming from your garden.
 
Let’s dig into the perfect scallion planting calendar so you never miss the window.
 

When To Plant Scallions Outside: The Simple Answer

Knowing when to plant scallions outside really comes down to understanding that these are cool-season champions.
 
Unlike tomatoes or peppers that sulk in the cold, scallions actually prefer the chill and will bolt (go to seed) if it gets too hot.
 
The best time to plant scallions outside is when the soil temperature has reached at least 40°F (4°C), though they germinate even better when it’s between 55°F and 65°F.
 
You can start sowing scallion seeds directly in the garden as soon as the ground thaws and is dry enough to work.
 
For most gardeners, this means you can plant scallions outside in early spring as soon as you can dig a furrow without it turning into mud.
 
If you live in a mild climate with winters that don’t freeze hard, you might even be able to plant scallions outside in fall for a winter harvest.
 
Let’s look at the two scallion planting windows that work for almost every growing zone.
 

Early Spring Planting for Scallions

The most popular time to plant scallions outside is in early spring.
 
About 4 to 6 weeks before your average last frost date, you can direct sow scallion seeds right into the garden bed.
 
Scallion seeds will germinate in soil as cold as 40°F, so don’t wait for the danger of frost to pass completely.
 
Frost won’t kill your young scallion seedlings; it just slows them down for a day or two.
 
This early spring scallion planting gives you a harvest in about 60 to 70 days, which means fresh scallions by late May or early June in most regions.
 
For a continuous supply, you can even sow a new batch of scallion seeds every two to three weeks until late spring.
 

Late Summer and Fall Scallion Planting

If you missed the spring window, don’t worry because you can plant scallions outside again in late summer.
 
About 8 to 10 weeks before your first expected fall frost, sow scallion seeds directly in the garden.
 
These fall-planted scallions will grow in the cooler autumn temperatures, which actually makes them even sweeter and milder.
 
You can also plant scallion sets (small immature bulbs) in fall for an extra-early harvest the following spring.
 
When you plant scallions outside in fall, they will establish roots and then go dormant over winter, ready to shoot up as soon as the soil warms.
 
This trick works brilliantly in zones 5 through 9, giving you scallions weeks ahead of your spring-sown crop.
 

Factors That Determine When To Plant Scallions Outside

Your exact planting date for scallions depends on a few key factors, not just the calendar.
 
Let’s break down the most important variables so you can nail the perfect scallion planting time for your garden.
 

Your Hardiness Zone and Local Frost Dates

The number one factor in when to plant scallions outside is your local frost calendar.
 
In colder zones like 3 and 4, you’ll plant scallions outside in early to mid-April.
 
In warmer zones like 7 and 8, you can plant scallions outside as early as March, and sometimes even February in zone 9.
 
Check your last frost date and simply subtract 4 to 6 weeks from that date for your spring scallion planting.
 
For fall scallion planting, count back 8 to 10 weeks from your first frost date.
 

Soil Temperature for Scallion Seeds

Scallion seeds can sprout in very cold soil, but the warmer the soil, the faster they germinate.
 
When you plant scallions outside in soil that’s around 40°F, germination can take up to three weeks.
 
When the soil hits 60°F, scallion seeds will sprout in about 7 to 10 days.
 
Use a soil thermometer if you want to be precise about when to plant scallions outside.
 
However, in early spring, it’s totally fine to just plant scallion seeds and wait patiently for them to emerge.
 

Growing Method: Seeds, Sets, or Transplants

What you’re planting changes when you should plant scallions outside.
 
If you’re sowing scallion seeds directly, you can plant them very early in the spring.
 
If you’re using scallion sets (small bulbs), you can plant them outside even earlier, as soon as the ground is workable.
 
If you started scallion seeds indoors under a grow light, you can transplant them outside about 2 to 3 weeks before your last frost.
 
Transplants give you a head start, but direct sowing is simpler for scallions since they grow so fast.
 

How To Plant Scallions Outside Successfully

Once you know when to plant scallions outside, the next step is getting them in the ground properly.
 
Scallions are one of the easiest vegetables to grow, but a few simple tips will make your crop even better.
 

1. Choose a Sunny Spot With Good Drainage

Scallions need at least 6 hours of direct sunlight each day.
 
They will tolerate partial shade, but full sun gives you the biggest, most flavorful scallions.
 
Make sure the soil drains well because scallions hate sitting in soggy, waterlogged ground.
 

2. Sow Seeds Shallowly and Thin Them Out

Scallion seeds are tiny, so plant them only about ¼ inch deep.
 
Space rows about 6 to 8 inches apart and scatter the seeds in a thin line.
 
Once the seedlings are about 2 inches tall, thin them to 1 to 2 inches apart.
 
You can eat the ones you pull out as micro scallions.
 

3. Keep the Soil Moist But Not Soaked

Scallions need consistent moisture to grow tender and juicy.
 
Water them regularly, especially when it’s dry, but don’t overwater.
 
A light mulch of straw or grass clippings helps retain moisture and keeps weed pressure down.
 

4. Feed Lightly for Bigger Scallions

Scallions aren’t heavy feeders, but a little compost worked into the soil before planting helps.
 
You can also side-dress with a balanced fertilizer about a month after planting.
 
Avoid high-nitrogen fertilizers as they can make scallions overly strong and harsh tasting.
 

So, When To Plant Scallions Outside?

You should plant scallions outside in early spring as soon as the soil is workable, and again in late summer for a fall crop.
 
This gives you scallions from late spring all the way through fall and even into winter in milder zones.
 
Remember that scallions are cold-hardy, so don’t stress about frost dates when you’re deciding when to plant scallions outside.
 
The key is to aim for those cool growing periods when temperatures are between 55°F and 75°F.
 
If you follow this scallion planting schedule, you’ll have a steady supply of fresh green onions for salads, stir-fries, and garnishes.
 
Now that you know when to plant scallions outside, grab your seeds and get growing.
 
Your garden will thank you.