Practical planning tools for short growing seasons.
Climate-based onion planting guide for Hay River, Northwest Territories
When to Plant Onions in Hay River
Onions are a more demanding choice in Hay River, usually favoring only the quickest and most climate-appropriate approaches.
Typical Planting Window
Risky in this climate
Use the planting dates below for onions in Hay River.
Start indoors
April 4
Typical planting windowMay 30 – June 13
MethodTransplant
Typical days to maturity95–110
Onions are usually started indoors around April 4 and planted outdoors during the normal local window of May 30 to June 13.
Most varieties need about 95–110 days to reach maturity once they are in the garden.
Onions are challenging in Hay River. Gardeners who succeed usually stack the odds with the fastest varieties, the best timing, and the warmest sites they have.
The main challenge with onions here is that the local season does not reliably leave enough room for the kind of finish gardeners usually want.
Best local strategy:
Treat this as a higher-risk crop and rely on earliness, warmth, and protection wherever possible.
Can Onions Mature in Hay River?
Growing degree days measure how much useful warmth typically accumulates during the season. For onions, this helps estimate whether local heat accumulation is usually enough for the crop to reach maturity on time.
Available GDD (base 45)1099
Typical crop GDD target1300
Heat margin-201
From the usual planting window, Hay River typically provides about 1099 growing degree days for onions. With a typical crop target of 1300, that leaves a heat margin of -201. That heat shortfall means the crop usually needs the fastest approach and the warmest local conditions to have a realistic chance of finishing well.
When Is It Too Late to Plant?
When planting later than usual, this table shows how much growing degree day heat is still available from each point in the season. As planting gets pushed back, the remaining heat drops and the crop becomes less likely to mature on time.
Checkpoint
Remaining GDD
Heat margin
Fit vs typical target
Apr 15
1287
-13
Usually short
Jun 1
1260
-40
Usually short
Jun 15
1155
-145
Usually short
Jul 1
961
-339
Usually short
How Different Onion Varieties Affect Results
In Hay River, very early onion varieties are usually the safest choice because they leave the least room for the season to turn against you. Slower classes are much less forgiving here.
Varieties that often fit well here include:
Walla Walla
— large and popular, but still best when started early enough to build size
Best Onion Varieties for Hay River
Onion variety choice matters in Hay River, especially when slower maturity ranges start spending too much local margin. The local season can support onions, so the main choice is usually about bulb size, sweetness, color, and keeping quality.
June 20
local season starts
August 24
frost pressure returns
Less heat used1099 GDD available
Hover or tap the dots to see which recommended varieties use that much local heat.
For Hay River, Walla Walla
is
the most realistic onion
option
for this short-season fit.
It needs
good timing, steady early growth, and realistic expectations.
Compare each variety’s heat need and maturity timing against the local frost-free window before choosing what to grow.
Closest matches for a marginal season
Walla WallaVery early
1100 GDD needed1099 available before frost
June 20August 24
Usually too long
Why this fit?
Local season fit:
Walla Walla is about 1 GDD short against the normal Hay River crop heat estimate.
Best for: large sweet onions.
A large, popular onion that can be rewarding, but still needs an early enough start to build size.
Tradeoff: Needs an early enough start to build size.
GDD comparisons are a planning shortcut, not a guarantee. Soil, watering, sowing depth, pests, transplant quality, and harvest goals still affect the final result.
Varieties that didn’t make the cut
These varieties are not the main picks for Hay River because they either run past the normal season or leave too little margin before frost.
ailsa craigLate
Needs1400 GDD
Hay River gives1099 GDD
Gap
301 GDD short
1099 GDD available before frost301 more GDD needed
June 20August 24
Runs past season
Why not a main pick?
Local season fit:
ailsa craig usually needs about 301 more GDD than Hay River provides before frost.
Best for: large exhibition onions.
A large onion that is more exposed in shorter seasons because it benefits from a longer finishing run.
Tradeoff: More exposed in shorter seasons.
pattersonMid-season
Needs1300 GDD
Hay River gives1099 GDD
Gap
201 GDD short
1099 GDD available before frost201 more GDD needed
June 20August 24
Runs past season
Why not a main pick?
Local season fit:
patterson usually needs about 201 more GDD than Hay River provides before frost.
Best for: long-keeping onions.
A solid keeping onion that wants enough runway to size up well before the season closes.
Tradeoff: Needs enough runway before the season closes.
redwingMid-season
Needs1300 GDD
Hay River gives1099 GDD
Gap
201 GDD short
1099 GDD available before frost201 more GDD needed
June 20August 24
Runs past season
Why not a main pick?
Local season fit:
redwing usually needs about 201 more GDD than Hay River provides before frost.
Best for: red storage onions.
A strong red onion that makes sense where the season is supportive enough for good bulb sizing.
Tradeoff: Needs a supportive season for good bulb sizing.
copraEarly
Needs1200 GDD
Hay River gives1099 GDD
Gap
101 GDD short
1099 GDD available before frost101 more GDD needed
June 20August 24
Runs past season
Why not a main pick?
Local season fit:
copra usually needs about 101 more GDD than Hay River provides before frost.
Best for: dependable storage onions.
A practical storage onion with good all-around usefulness when started early.
Tradeoff: Still needs enough season to size up.
Variety class
Typical days to maturity
Typical GDD need
Local fit
Very early
90–95
1100
Tight
Early
95–105
1200
Poor fit
Mid-season
105–115
1300
Poor fit
Late
115–120
1400
Poor fit
Main risk: The main issue here is usually simple season length: the crop often runs out of time before finishing properly.
How Frost Affects Planting Dates for Onions in Hay River
Hay River usually has about 65 frost-free days, with a typical last spring frost around June 20 and a typical first fall frost around August 24.
Typical last spring frostJune 20
Typical first fall frostAugust 24
Typical frost-free days65
Minimum safe temperature28°F /
-2
°C
Onions are generally
lightly frost tolerant
and temperatures below about 28°F (
-2
°C) can slow growth or damage plants.
Onions are usually tolerant enough of cool conditions that frost dates act more like planning markers than hard limits. In practice, timing and steady early growth matter more than avoiding every light frost.
The crop usually falls short here because the season runs out before it finishes well. Late planting, cool nights, and slower varieties make that problem much worse.
In Hay River, the local season often leaves onions close to practical limits, so warmer sites are usually part of the plan rather than just an advantage. Local gardens do not all warm and cool at the same pace. In practical terms, the best spots are usually south-facing walls, sheltered gardens, raised beds, and sunnier urban lots. Cooler spots like low spots, exposed sites, and shadier yards are more likely to stay cooler and be less forgiving. For onions, warmer local sites usually help the crop get established earlier and grow a little more steadily.
Protect onions with strong starts and steady moisture
The useful setup is about strong early growth, steady moisture, and getting the crop to a clean finish.
Soil and planting setup
For storage crops, the best gains usually come from strong early growth and a clean finish.
