You can plant celery in late spring once nighttime temperatures stay above 50°F, and you can also start celery seeds indoors about 10 to 12 weeks before that date for a head start.
If you have ever wondered when to plant celery, the short answer is that celery is a cool-season crop that you plant in spring for a summer harvest or in late summer for a fall harvest.
Celery is fussy about temperature, so timing means everything.
In this post, we will cover how and when to plant celery, including starting seeds indoors, transplanting seedlings outside, and caring for your crop so it thrives.
Let’s dig in.
When to Plant Celery
Knowing when to plant celery starts with understanding its preferred growing conditions.
Celery grows best when daytime temperatures sit between 60°F and 70°F, and it bolts or turns bitter when the heat climbs above 75°F for too long.
That narrow window is why when you plant celery matters so much.
1. Start Seeds Indoors 10 to 12 Weeks Before Your Last Frost
The best way to plant celery is to start it indoors rather than direct sowing.
Celery seeds are tiny and slow to germinate, often taking two to three weeks to sprout.
So if you want strong transplants ready for spring, you should plant celery seeds indoors about 10 to 12 weeks before your last expected frost date.
2. Transplant Outside After the Last Frost
When to plant celery outside depends on your local frost dates.
Wait until all danger of frost has passed and the soil has warmed to at least 55°F.
If you plant celery too early, cold snaps can cause the plants to bolt and produce tough, stringy stalks.
3. Plant a Fall Crop in Late Summer
You can also plant celery in late summer for an autumn harvest.
Count backward from your first fall frost, and you can plant celery about 12 to 14 weeks before that date.
Cool fall air is actually ideal, and many gardeners find that when they plant celery in late summer, the flavor is sweeter.
How to Plant Celery
Once you know when to plant celery, the next step is getting the planting method right.
Celery has shallow roots and a big appetite, so how you plant celery directly affects how well it grows.
1. Start With Rich, Moist Soil
You should plant celery in soil that is loose, fertile, and holds moisture well.
Mix in plenty of compost before you plant celery, because the plants feed heavily and need consistent nutrients.
A soil pH between 6.0 and 7.0 works best for celery.
2. Sow Seeds on the Surface
When you plant celery seeds, press them gently into the soil surface rather than burying them.
Celery seeds need light to germinate, so a light dusting of soil is all you need.
Keep the soil consistently moist, and you can plant celery seeds in trays or small pots indoors.
3. Harden Off Before Transplanting
Before you plant celery seedlings in the garden, harden them off over seven to ten days.
Set them outside for a few hours each day, gradually increasing their time outdoors.
This step helps you plant celery successfully without shocking the tender seedlings.
4. Space Plants 8 to 10 Inches Apart
When you plant celery in the garden, space the seedlings 8 to 10 inches apart in rows about two feet apart.
Plant celery at the same depth it was growing in its pot, and water immediately after.
Good spacing lets air move around the plants, which helps prevent disease.
Caring for Celery After You Plant It
After you plant celery, the work is not done, because celery is a thirsty, hungry crop.
Here is how to keep it happy once you plant celery in your garden.
1. Water Consistently
Celery needs steady moisture, so water deeply once or twice a week.
Never let the soil dry out completely, but do not drown the roots either.
A layer of mulch helps hold moisture after you plant celery.
2. Feed Every Few Weeks
Since you plant celery in nutrient-rich soil, side-dress with compost or a balanced fertilizer every three to four weeks.
Consistent feeding keeps the stalks tender and crisp.
3. Blanch the Stalks for Sweeter Flavor
About two weeks before harvest, you can tie the stalks together or wrap them to blanch them.
This blocks light and makes the celery milder and less bitter.
So, How and When to Plant Celery?
You can plant celery in late spring after the last frost, or start seeds indoors 10 to 12 weeks earlier, and you can also plant celery in late summer for a fall harvest.
The key is timing your planting around cool weather, since celery bolts in heat and sulks in cold.
Plant celery in rich, moist soil, keep it watered and fed, and you will be rewarded with crisp, flavorful stalks.
Hope this guide to how and when to plant celery helps you grow a healthy, happy crop this season.