Quick Answer: When to Plant Onion Transplants in Kentucky Plant onion transplants outdoors in April 1–June 15 in western Kentucky, March 25–July 1 in central Kentucky, and late March in eastern Kentucky, according to the University of Kentucky. Onions are cold-tolerant and can handle light frosts. For Kentucky, grow intermediate or long day varieties.
Use your zip code at Farmer’s Almanac to find your exact frost date.
Back in December, I sat down with a seed catalog and a cup of coffee and ordered onion transplants from Dixondale Farms. Diondale sends a nice simple catalog. March felt like a long way away. I planned my ship date, entered my frost date — and then realized I had my frost date wrong.
One email to Dixondale’s customer service and they adjusted my ship date without any fuss. Bonnie is amazing. On March 27th a bundle of what looked like sad, dry sticks arrived at my door. Candy onions and Blush onions — two varieties I’d researched carefully for our Kentucky growing conditions.
They go in the ground April 7th (my plan) alongside my broccoli transplants. This post covers everything I’ve learned about when to plant onions in Kentucky, why I choose transplants over sets or seeds, and what to do when your Dixondale order arrives looking like it didn’t survive the journey.
Spoiler: it did. They always do.
👩🌾 From my homestead: I garden in Zone 7a in south central Kentucky, Adair County. My frost-free date is April 20th. I’ve grown onions for two years now — both times from Dixondale transplants. I’m not affiliated with Dixondale. I just ordered from them because they’re good.
When to Plant Onions in Kentucky
Onions are one of the earliest crops you can get in the ground in Kentucky — they’re cold-tolerant and can handle light frosts which makes them a March planting in most of the state. The University of Kentucky Cooperative Extension Service ID-128 gives us the most reliable dates broken into Western, Central, and Eastern Kentucky regions.
| Method | Western KY (Zone 7a/7b) |
Central KY (Zone 7a) |
Eastern KY (Zone 6b) |
Notes |
|---|---|---|---|---|
| 🧅 Spring — Earliest Safe Planting Date | ||||
| Transplants (plants) | Mar 15 | Mar 25 | Apr 1 | Cold tolerant, handles light frost |
| Sets (small bulbs) | Mar 1 | Mar 10 | Mar 15 | Earliest method, very frost hardy |
| Seeds (direct sow) | Mar 10 | Mar 20 | Apr 1 | Slowest method, needs most time |
| 🧅 Latest Safe Planting Date (Spring only per ID-128) | ||||
| Transplants | July 15 | July 1 | June 15 | Spring crop only in most of KY |
🧅 Tip: Not sure which region you’re in? Western Kentucky is roughly Zone 7a/7b, Central Kentucky is Zone 7a, Eastern Kentucky is Zone 6b. Enter your zip code at Farmer’s Almanac to find your exact frost free date.
Source: University of Kentucky Cooperative Extension Service ID-128 Table 20.14 — Vegetable Gardener’s Calendar for Western, Central, and Eastern Kentucky.
→ See the complete Kentucky Vegetable Planting Calendar for all spring crops.
You’ll notice I’m planting my transplants on April 7th — slightly later than the earliest safe date for central Kentucky. Life happens. Onions are forgiving, and April 7th is still well within the safe window. I am trying to get to them earlier. I will update if i get them in!
Want a full Kentucky garden calendar straight to your inbox?
Why I Choose Transplants Over Sets or Seeds
You can grow onions three ways in Kentucky — from transplants, from sets (small bulbs), or from seed. I’ve only grown transplants so far and here’s honestly why:
- Transplants — young plants grown from seed and shipped to you at planting time. More variety selection than sets, faster than starting from seed yourself. This is what Dixondale sells.
- Sets — small partially grown bulbs. Easiest and fastest to establish. Limited variety selection. I haven’t tried these yet.
- Seeds — start indoors in January for spring planting. Most variety selection, most work. Haven’t tried this either.
I chose transplants because I was afraid I’d kill the seedlings, and the sets I have tried did not grow. So for me, transplants it is! Ordering from Dixondale gave me exactly what I wanted, shipped directly to my door.
🧅 Tip: If you’re new to growing onions, start with transplants. They establish quickly, they’re hard to kill, and you get access to far more variety choices than sets from a garden center.
Ordering from Dixondale — What to Expect
Dixondale Farms has been growing and shipping onion transplants for over 100 years. You pick your shipment time specifically for your planting region — you tell them when you want to plant, and they ship accordingly.
When they arrive
Here’s what nobody tells you the first time — your onion transplants will look completely wilted and scraggly when they arrive. Dry, limp, papery. Don’t panic. Dixondale’s own planting guide explains it perfectly: the plants are simply dormant and can live off the bulb for approximately three weeks.
- Remove plants from the box immediately
- Do not put in soil or water before planting
- Keep cool and dry until you can plant
- They can wait up to three weeks if needed
👩🌾 From my homestead: Mine arrived March 27th and looks exactly like sad dry limp plants. They go in the ground April 7th (earlier if my schedule eases up) plus we are getting another frost on 3/28/2026 — 11 days after arrival. According to Dixondale that’s completely fine. I’m keeping them in a cool dry spot in my basement until planting day.
🧅 My varieties this year
Candy — an intermediate day sweet onion that performs well across Kentucky. Sweet, reliable, a classic choice for our region.
Blush — a unique hybrid with beautiful pink and purple internal rings. 5-6 month storage potential. Johnny’s Seeds confirmed it grows down to 38 degrees latitude — I’m just below that at 37 degrees in Adair County, right on the edge. Worth trying.
Full planting guide from Dixondale: dixondalefarms.com/onion-planting-guide/
What Onions Need to Thrive in Kentucky
From the UK Extension onion guide and Dixondale’s planting recommendations:
- Full sun — onions need direct sun, no shade
- Good drainage — raised beds or raised rows at least 4 inches high work best
- Loose soil — work in compost if your soil is compacted. Kentucky clay needs amendment.
- Nitrogen — onions are heavy feeders. Dixondale recommends their 10-20-10 fertilizer at planting, then ammonium sulfate every 2-3 weeks until bulbing begins.
- Intermediate or long day varieties — Kentucky gardeners should grow intermediate or long day onions. Short day varieties won’t bulb properly in our latitude.
🧅 Tip: Kentucky’s clay soil holds nutrients but compacts easily. Work in compost before planting onions — loose, crumbly soil produces bigger better bulbs.
Planting Onions with Broccoli
My onions are going in the ground on April 7th alongside my broccoli transplants — and that’s not just convenient timing, it’s actually good companion planting. The strong scent of onions is thought to deter the cabbage butterflies that lay eggs on broccoli, the same worm problem that got my broccoli last year.
Two problems solved with one planting day, well most likely 2 days lol.
Read more about my broccoli worm strategy here: When to Plant Broccoli in Kentucky → bloomandpeck.com/when-to-plant-broccoli-kentucky/
And my full companion planting series: Kentucky Companion Planting Guide → bloomandpeck.com/kentucky-companion-planting/
Update Coming April 7th
This post is a living document — I’ll be back on April 7th with photos of the full planting day. Onions and broccoli going in the ground together, the Blush variety up close, the raised bed setup, all of it.
In the meantime, if you have questions about ordering from Dixondale or choosing varieties for Kentucky, drop them in the comments — happy to share what I know.
Happy growing,
Bloom & Peck Farm
FAQ — When to Plant Onions in Kentucky
When is the best time to plant onions in Kentucky?
March is the sweet spot for most of Kentucky. Western Kentucky can plant transplants as early as March 15th, central Kentucky around March 25th, and eastern Kentucky April 1st. Onions are cold tolerant and handle light frosts well.
Should I grow onions from transplants, sets, or seeds in Kentucky?
All three work in Kentucky. Transplants from a specialist grower like Dixondale give you the most variety selection and establish quickly. Sets are the easiest and earliest. Seeds give you the most options but require starting indoors in January. I’ve only grown transplants so far and recommend them for beginners.
What onion varieties grow best in Kentucky?
Kentucky gardeners should grow intermediate or long day onion varieties — short day varieties won’t bulb properly at our latitude. Good choices include Candy (intermediate day, sweet), and storage varieties like Patterson or Red Bull. I’m also trying Blush this year — a unique pink hybrid that grows down to 38 degrees latitude.
Can I plant onions with broccoli in Kentucky?
Yes — onions and broccoli are good companions. The strong scent of onions may deter the cabbage butterflies that lay eggs on broccoli. They go in the ground at similar times in spring which makes planting day efficient too.
What do I do when my Dixondale onions arrive?
Don’t panic when they look dead — they’re dormant, not dead. Remove from the box immediately, keep cool and dry, and don’t put in soil or water until planting day. They can survive up to three weeks this way. Full instructions at dixondalefarms.com/onion-planting-guide/
What happens if I plant onions too early in Kentucky?
Onions are very cold tolerant and can handle light frosts down to 20°F once established. Planting too early (before March 1) risks frozen soil preventing transplanting, but onions rarely suffer from cold damage in Kentucky springs.
How long do onions take to grow in Kentucky?
From March/April transplanting, onions mature in 90-120 days depending on variety. Expect harvest in June-July for spring-planted onions. Short day varieties mature faster (90 days), long day varieties take longer (120 days).
Resources & Further Reading
- UK Cooperative Extension — Growing Onions Guide (NEP-245): publications.mgcafe.uky.edu/sites/publications.ca.uky.edu/files/NEP245.pdf
- UK Cooperative Extension — Home Vegetable Gardening in Kentucky (ID-128): publications.mgcafe.uky.edu/files/ID128.pdf
- Dixondale Farms Onion Planting Guide: dixondalefarms.com/onion-planting-guide/
More From Bloom & Peck Farm
- When to Plant Broccoli in Kentucky → bloomandpeck.com/when-to-plant-broccoli-kentucky/
- When to Plant Peas in Kentucky → bloomandpeck.com/when-to-plant-peas-kentucky/
- When to Plant Beets in Kentucky → bloomandpeck.com/when-to-plant-beets-kentucky/ (coming soon)
- Kentucky Gardening Hub → bloomandpeck.com/kentucky-gardening/
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