Practical planning tools for short growing seasons.
Climate-based potato planting guide for Sudbury, Ontario
When to Plant Potatoes in Sudbury
Potatoes are usually a comfortable fit in Sudbury. The season is generally supportive enough that consistency, sizing, and harvest goals matter more than season pressure.
Typical Planting Window
Excellent fit in this climate
Use the planting dates below for potatoes in Sudbury.
Typical planting windowMay 4 – May 18
MethodDirect sow
Typical days to maturity80–100
Potatoes are usually sown directly outdoors around April 27, with a typical local planting window of May 4 to May 18.
Most varieties need about 80–100 days to reach maturity.
Potatoes are usually a comfortable fit in Sudbury. Gardeners usually get the best results when they use that margin to improve finish quality and uniformity.
Even here, the climate does not guarantee an even finish. The better results still come from steady growth, consistent sizing, and harvesting when the crop is actually ready.
Best local strategy:
Plant in the normal window and use the extra margin to focus on steady growth, plant health, and finishing cleanly.
Can Potatoes Mature in Sudbury?
Growing degree days measure how much useful warmth typically accumulates during the season. For potatoes, this helps estimate whether local heat accumulation is usually enough for the crop to reach maturity on time.
Available GDD (base 45)2123
Typical crop GDD target1100
Heat margin+1023
From the usual planting window, Sudbury typically provides about 2123 growing degree days for potatoes. With a typical crop target of 1100, that leaves a heat margin of +1023. That large heat margin means season length is usually not the limiting issue here. The more useful question is how gardeners use that room to improve sizing, finish quality, and harvest timing.
When Is It Too Late to Plant?
If planting later than usual, this table shows how much growing degree day heat is still available from each point in the season. For potatoes, it is most useful for judging how much freedom you still have to plant for quality, finish, and harvest goals as the season moves along.
Checkpoint
Remaining GDD
Heat margin
Fit vs typical target
Apr 15
2146
+1046
Comfortable
May 15
2116
+1016
Comfortable
Jun 1
1952
+852
Comfortable
Jun 15
1754
+654
Comfortable
Jul 1
1471
+371
Comfortable
How Different Potato Varieties Affect Results
Most potato varieties can succeed in Sudbury in a typical year. That gives gardeners room to choose for the kind of harvest they want, not just for minimum maturity speed.
Varieties that often fit well here include:
Yukon Gold
— widely grown and relatively approachable where gardeners want dependable earlier harvest
Norland
— often chosen for earliness and good fit in shorter-season gardens
Dark Red Norland
— a familiar early potato with solid short-season appeal
Kennebec
— productive and versatile, but better with a decent amount of runway
Gold Rush
— can do well where the season is supportive and planting is timely
Russet Burbank
— more exposed in short-season areas because it wants a longer finish
Best Potato Varieties for Sudbury
Mid-season potato varieties are usually the strongest all-around match in Sudbury. The local season can support potatoes, but early types give more cushion while main-crop types ask for a longer finish.
May 18
local season starts
October 1
frost pressure returns
Less heat used2123 GDD available
Hover or tap the dots to see which recommended varieties use that much local heat.
For Sudbury, start with Kennebec and Gold Rush for potatoes when you want dependable main-crop potatoes or main-crop russets.
Choose Norland and Yukon Gold when you want early potato harvests or early yellow potatoes.
Look at Russet Burbank and Dark Red Norland when you specifically want long-season russets or early red potatoes.
Compare each variety’s heat need and maturity timing against the local frost-free window before choosing what to grow.
Recommended starting point
KennebecMid-season
1100 GDD needed2123 available before frost
May 18October 1
Comfortable fit
Why this fit?
Local season fit:
Kennebec leaves about 1023 GDD cushion against the normal Sudbury crop heat estimate.
Best for: dependable main-crop potatoes.
A productive, versatile potato that makes sense when the season has enough room for a solid main-crop harvest.
Tradeoff: Needs more runway than early potatoes.
Gold RushMid-season
1100 GDD needed2123 available before frost
May 18October 1
Comfortable fit
Why this fit?
Local season fit:
Gold Rush leaves about 1023 GDD cushion against the normal Sudbury crop heat estimate.
Best for: main-crop russets.
A russet-type potato that can do well with timely planting and enough runway, but is less forgiving than faster early potatoes.
Tradeoff: Less forgiving than early potatoes.
Fastest / most cushion
NorlandVery early
900 GDD needed2123 available before frost
May 18October 1
Comfortable fit
Why this fit?
Local season fit:
Norland leaves about 1223 GDD cushion against the normal Sudbury crop heat estimate.
Best for: early harvests.
A reliable early potato choice when you want a shorter-season crop with less pressure on the back end of the season.
Tradeoff: More about speed than maximum main-crop yield.
Yukon GoldVery early
900 GDD needed2123 available before frost
May 18October 1
Comfortable fit
Why this fit?
Local season fit:
Yukon Gold leaves about 1223 GDD cushion against the normal Sudbury crop heat estimate.
Best for: early yellow potatoes.
A familiar yellow potato that gives gardeners a faster, more forgiving path than longer-season storage types.
Tradeoff: Not a long-season storage russet.
Also realistic
Russet BurbankLate
1250 GDD needed2123 available before frost
May 18October 1
Comfortable fit
Why this fit?
Local season fit:
Russet Burbank leaves about 873 GDD cushion against the normal Sudbury crop heat estimate.
Best for: long-season russets.
A classic long-season russet that is better treated as a stretch or specialty choice unless the local season gives it plenty of room.
Tradeoff: A stretch in short-season areas.
Dark Red NorlandEarly
1000 GDD needed2123 available before frost
May 18October 1
Comfortable fit
Why this fit?
Local season fit:
Dark Red Norland leaves about 1123 GDD cushion against the normal Sudbury crop heat estimate.
Best for: early red potatoes.
A red-skinned early potato that can work well when you want something a little more substantial than the very fastest choices.
Tradeoff: Needs more room than the very fastest potato choices.
GDD comparisons are a planning shortcut, not a guarantee. Soil, watering, sowing depth, pests, transplant quality, and harvest goals still affect the final result.
Variety class
Typical days to maturity
Typical GDD need
Local fit
Very early
70–80
900
Good fit
Early
80–90
1000
Good fit
Mid-season
90–105
1100
Good fit
Late
105–120
1250
Good fit
Main risk: The usual setbacks here come from management choices rather than from the season itself.
How Frost Affects Planting Dates for Potatoes in Sudbury
Sudbury usually has about 136 frost-free days, with a typical last spring frost around May 18 and a typical first fall frost around October 1.
Typical last spring frostMay 18
Typical first fall frostOctober 1
Typical frost-free days136
Minimum safe temperature28°F /
-2
°C
Potatoes are generally
lightly frost tolerant
and temperatures below about 28°F (
-2
°C) can slow growth or damage plants.
Potatoes 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 most common problems here are not climatic ones. Gardeners usually lose ground through timing, uneven growth, or letting the crop move past its best stage.
In Sudbury, potatoes usually have a solid seasonal margin when planted around April 27. The warmest garden spots are usually south-facing walls, sheltered gardens, raised beds, and sunnier urban lots. Cooler spots like low spots, exposed sites, and shadier yards tend to warm up later and usually provide less heat. For potatoes, warmer garden spots usually improve early growth and can make timing a little more forgiving.
Set up potatoes for sizing, watering, and storage
The biggest gains usually come from better planting setup, steady moisture, good sizing, and clean harvest handling rather than season extension.
Soil and planting setup
For storage crops, the best gains usually come from strong early growth and a clean finish.