When to Plant Peas in Ontario
Early sow dates for every Ontario city, why planting early is everything, succession sowing strategy, best varieties by zone, fall peas, and pest and disease control for Toronto, Ottawa, Hamilton, Windsor, London, Kingston, Kitchener, Sudbury, and Thunder Bay.
When to plant peas in Ontario comes down to one rule that most gardeners get wrong: plant earlier than you think. Peas are a cool-season crop that germinates in near-freezing soil and tolerates hard frost — waiting until last frost to sow them is waiting too long. By the time Ontario's late April and May last-frost dates arrive, the cool growing window is already half spent.
This guide covers exact sow dates for every major Ontario city, why Ontario's pea season is short and how to make the most of it, succession sowing for the longest possible harvest, the right varieties for each zone, fall pea sowing for a second crop, and the pests and diseases Ontario pea growers encounter most.
Ontario peas at a glance: Sow as early as soil is workable above 4°C. Windsor/Toronto: late March–early April. Ottawa: April 10–20. Direct sow only — never transplant. Peas tolerate hard frost. Season ends when heat exceeds 24°C — typically late June to mid-July. Succession sow every 2–3 weeks.
Outside Ontario? See the Canada-wide pea planting guide for dates in BC, Quebec, the Prairies, and the Maritimes — plus a fall sowing window most gardeners miss.
Ontario Pea Planting Dates by City — 2026
The first sow date is as soon as soil is workable above 4°C — not last frost. Season ends when July heat consistently exceeds 24°C. Every week of delay at the start costs a week of harvest at the end.
| City | Zone | Last Frost | First Sow | Harvest Window | Season Ends |
|---|---|---|---|---|---|
| Windsor | 7a | Apr 20 | Mar 20–Apr 1 | Late May–late Jun | Late Jun–early Jul |
| Toronto | 6b | Apr 20 | Mar 25–Apr 5 | Early Jun–early Jul | Early–mid Jul |
| Hamilton | 6b | Apr 25 | Apr 1–10 | Early Jun–early Jul | Early–mid Jul |
| London | 6a | Apr 30 | Apr 1–10 | Jun–early Jul | Early–mid Jul |
| Kitchener | 5b | May 9 | Apr 5–15 | Jun–mid Jul | Mid Jul |
| Kingston | 5b | May 5 | Apr 5–15 | Jun–mid Jul | Mid Jul |
| Ottawa | 5a | May 9 | Apr 10–20 | Jun–mid Jul | Mid Jul |
| Sudbury | 5a | May 20 | Apr 10–20 | Jun–mid Jul | Mid Jul |
| Thunder Bay | 3b | May 25 | Apr 15–25 | Jun–mid Jul | Mid Jul |
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🌿 Free Seed Starting CalculatorOntario's Short Pea Season — Why Early Planting Is Everything
Peas are one of the few vegetables in the Ontario garden where earlier is almost always better. The 24°C threshold that ends pod production is not negotiable — and Ontario's summer arrives on its own schedule regardless of when you sow.
Germination minimum
Peas germinate from 4°C. Ontario's early April soil is already above this — there is no reason to wait for warmer conditions.
Toronto July avg
Well above the shutdown threshold. The season ends regardless of plant vigour once July heat arrives.
Weeks of harvest
Ontario's total pea season per sowing. Succession sowings extend the total harvest window.
Shutdown threshold
Above this consistently, peas stop flowering and shut down. Ontario crosses it every July.
How to Sow and Grow Peas in Ontario
Direct sow only — never transplant
Peas develop a deep taproot immediately after germination. Transplanting disrupts this root system and causes significant setback or death. There is no benefit to starting peas indoors in Ontario — unlike tomatoes or peppers, peas thrive in cold soil and do not need a head start. Sow directly into the garden 2.5 cm deep, 5–8 cm apart, in single or double rows 15–20 cm apart. In Ontario's heavy clay soils (common in Hamilton, London, Ottawa), add compost before sowing to improve drainage and reduce surface crusting that can impede emergence.
Soil preparation and inoculant
Peas prefer well-drained soil with a pH of 6.0–7.5. They fix their own nitrogen and do not benefit from nitrogen-rich beds — excess nitrogen produces lush vines with few flowers and pods. Work aged compost into the bed before sowing but avoid fresh manure. In beds new to peas or beans, coat seeds with Rhizobium leguminosarum inoculant just before sowing — it establishes the nitrogen-fixing relationship from the first roots. Apply in the shade; sunlight degrades the bacteria quickly. In Ontario's cold April soil where bacterial activity is naturally slower, inoculant makes a measurable difference to germination rate and early vigour.
Succession sowing — essential for a decent Ontario harvest
A single pea sowing in Ontario produces a 3–4 week harvest window before heat ends it. Sowing every 2–3 weeks from the first sow date through late April extends the total harvest significantly. Three successive sowings — for example March 30, April 14, and April 28 in Toronto — staggers the harvest from early June through mid-July, giving 6–8 weeks of continuous production rather than 3–4 weeks of peak yield followed by nothing. The last sowing in late April gives the final harvest just as July heat arrives. There is no point sowing after May 1 in most Ontario cities — the plants will barely reach harvest before shutting down.
Trellis — install at sowing time
Climbing peas send out tendrils from the first few leaf sets — they will find and climb whatever is available immediately after emergence. Install trellis, netting, or twiggy brush support before sowing. Pushing stakes in after seedlings appear disturbs roots in Ontario's spring soil. Bush varieties (Sugar Ann, Little Marvel, Maestro) reach 45–60 cm and are self-supporting with minimal assistance, but even these benefit from a short stake or net in Ontario's spring wind. Vertical growing improves airflow and reduces the powdery mildew pressure that arrives as Ontario's humid summer develops.
Watering
Ontario's April and May usually provide adequate rainfall for spring pea crops — supplemental watering is rarely needed during the main growing period. The exception is dry spells during flowering and pod-set in late May and June, when consistent moisture is critical. Water at the base only; wet foliage accelerates the powdery mildew and fungal diseases that increase as Ontario's humid June and July arrive. Fall-sown peas in August require consistent irrigation through emergence and early growth — Ontario's August is reliably dry and warm, creating real moisture stress for fall sowing.
Pick every 2 days at peak
Leaving mature pods on the vine signals the plant to stop producing new flowers. Pick sugar snaps when pods are round and firm. Pick snow peas when pods are flat and 6–8 cm long, before seeds develop inside. Pick shelling peas when pods are plump and full but before they yellow. In Ontario's short warm season, pods develop and overmature quickly — checking plants every 2 days at peak is not excessive. Shelling peas lose sweetness within hours of harvest as sugar converts to starch; cook or refrigerate immediately. Given Ontario's short overall window, no pod should be left on the vine past its prime.
Best Pea Varieties for Ontario
Days to harvest matters more in Ontario than in coastal BC — faster varieties maximise the harvest window before July heat arrives. Ottawa and Kingston gardeners especially should favour 50–62 day varieties. Toronto and Windsor have slightly more room for longer-season types.
| Variety | Type | Days | Best Zones | Notes |
|---|---|---|---|---|
| Sugar Ann | Snap / bush | 52 days | All zones | Best Ontario pea — fastest snap, no trellis, maximum harvest before heat. Essential for Ottawa and Kingston's tighter window. |
| Little Marvel | Shelling / bush | 60 days | All zones | Compact, no trellis. Outstanding sweet flavour. Reliable producer across all Ontario climates. Excellent for freezing. |
| Maestro | Shelling / bush | 61 days | All zones | Disease-resistant and reliable. No trellis. Pods well-filled and long. Practical all-round choice for Ontario home gardens. |
| Oregon Sugar Pod | Snow / semi-climbing | 60 days | All zones | Best snow pea for Ontario. Large sweet flat pods. Some pea enation mosaic virus resistance. Needs light support. |
| Super Sugar Snap | Snap / climbing | 65 days | Toronto / Windsor | Mildew-resistant improvement on Sugar Snap. Best for Toronto and Windsor where the extra 13 days fits in the season. |
| Lincoln | Shelling / semi-climbing | 65 days | Toronto / Windsor | Best-flavoured shelling pea. Rich and sweet. Eat immediately. Toronto and Windsor have enough cool season for this variety to perform. |
| Wando | Shelling / bush | 68 days | Toronto / Windsor | Most heat-tolerant pea. Extends harvest into early July when other varieties have shut down. Best for fall sowing across all Ontario zones. |
Fall Peas in Ontario — A Second Crop
Fall peas are possible across most of Ontario but are more challenging than the spring crop — August heat and drought stress seedlings during germination, and the window between soil cooling enough for germination and autumn frost is narrow. Use fast varieties, keep soil consistently moist, and accept lower yields than spring.
| City | Fall Sow | Fall Harvest | Best Variety | Notes |
|---|---|---|---|---|
| Windsor | Aug 20–Sept 1 | Oct–Nov | Sugar Ann, Wando | Best Ontario fall pea window |
| Toronto | Aug 15–25 | Oct | Sugar Ann | Possible — keep soil moist in Aug heat |
| Hamilton / London | Aug 15–25 | Oct | Sugar Ann | Possible — use fast variety only |
| Kingston | Aug 10–20 | Sept–Oct | Sugar Ann only | Marginal — first frost by mid-Oct |
| Ottawa | Aug 10–20 | Sept–Oct | Sugar Ann only | Marginal — first frost by mid-Oct |
Pests and Diseases in Ontario
Ontario peas face the same core threats as BC peas — pea moth, aphids with virus transmission, and powdery mildew — but the timeline differs. Most pest and disease pressure in Ontario builds in June and July, right as the season is ending, rather than persisting through a long coastal summer.
Pea moth
The pea moth (Cydia nigricana) lays eggs on pea flowers from late May through June in Ontario. Larvae hatch and eat developing peas inside pods, leaving entry holes and caterpillars in harvested pods. There is no effective spray once larvae are inside. Row cover installed at first flowering prevents egg-laying — peas self-pollinate and do not require insect access, so row cover can stay in place through harvest. Look for small circular holes on pods and webbing inside when shelling. Crop rotation reduces overwintering pupae and lowers pressure season over season.
Pea aphid and pea enation mosaic virus
Pea aphids (Acyrthosiphon pisum) are large pale green aphids that cluster on growing tips and leaf undersides, distorting new growth. Knock off with a firm water stream; insecticidal soap controls persistent colonies. The larger concern is that pea aphids vector pea enation mosaic virus (PEMV) — causing yellow mosaic leaf patterns, bumpy enation growths on pod surfaces, severe stunting, and very poor yield. There is no cure; remove and bag infected plants immediately to prevent aphid-mediated spread to healthy plants. Control aphid populations early in the season, before the virus establishes across the planting. Oregon Sugar Pod has some PEMV resistance.
Powdery mildew — late-season Ontario
Powdery mildew (Erysiphe pisi) appears as white powdery coating on leaves and stems, typically from late June through July as Ontario's humidity builds and temperatures rise. It is very common on Ontario peas near the end of the spring season and on fall-sown crops in September. Mildew rarely causes early-season damage — it arrives when heat is already ending production anyway. Choose mildew-resistant varieties (Super Sugar Snap, Maestro) to extend the tail end of the harvest. Space plants adequately and water at the base only. On fall-sown peas, mildew is more of a problem because the plants have longer to develop it — airflow and resistant varieties matter more for fall crops than spring ones.
Common Pea Problems in Ontario
Planted too late — the most common Ontario mistake
Waiting for last frost to plant peas is the single most common mistake Ontario gardeners make with this crop. Peas love cold, tolerate hard frost, and germinate from 4°C — there is no reason to wait for conditions to warm. A Toronto gardener who waits until May 1 to plant, following the last-frost rule that makes sense for tomatoes, has already lost 5 weeks of optimal pea-growing time. The plants will barely reach full harvest before the July heat ends the season. If you have done this in past years and wondered why your pea harvest felt underwhelming, planting 4–6 weeks earlier will be a revelation.
Plants suddenly stop producing
Production stopping abruptly in late June or early July is almost always heat shutdown — normal, inevitable, and not a sign anything went wrong. Once Ontario temperatures consistently exceed 24°C, peas stop flowering and existing pods quickly overmature. This is the end of the spring season. Lush green vines with few pods in June when production should be at peak usually indicate excess nitrogen — do not fertilise peas with nitrogen-rich materials. If plants are productive but individual pods look small and pale, check for pea moth larvae inside — damage from larvae can significantly reduce pod quality without visibly affecting plant health.
Yellowing plants with mosaic patterns
Mosaic-patterned or mottled yellow-green leaves on stunted, unproductive plants are the signature of pea enation mosaic virus (PEMV), transmitted by pea aphids. It is present across Ontario and more common than many gardeners realise. Remove affected plants immediately — bagging, not composting — to prevent aphid-mediated spread to healthy plants. Normal lower leaf yellowing on a productive plant is simply the plant drawing nitrogen back from old leaves as it ages, and is not a disease symptom. Yellowing with dark lesions on stems or pods may indicate fungal disease; improve airflow and avoid overhead watering.
Frequently Asked Questions
When should I plant peas in Ontario?
As early as soil is workable above 4°C — not last frost. Windsor/Toronto: March 20–April 5. Hamilton/London: April 1–10. Kingston: April 5–15. Ottawa: April 10–20. Every week of delay in March or April costs a week of harvest before July heat ends the season. Peas tolerate hard frost — do not wait for warm weather.
How long is the pea season in Ontario?
4–7 weeks per sowing, ending when July heat consistently exceeds 24°C. Succession sowings every 2–3 weeks from late March through late April give 6–8 weeks of total harvest. After that, peas are done until the fall crop. The season is substantially shorter than coastal BC's 12–16 weeks — the 24°C shutdown threshold is the reason.
Can I start peas indoors in Ontario?
No — peas develop a taproot immediately after germination and transplant poorly at any stage. Direct sowing in cold soil is the correct method. Ontario's early April soil is already above the 4°C germination threshold — there is no cold-soil problem to solve. Starting indoors only creates a transplant setback that eliminates any timing advantage.
What is the best pea variety for Ottawa and Kingston?
Sugar Ann (52 days, bush snap) — the fastest reliable pea variety, no trellis required, and it fits comfortably into the shorter cool season of Ottawa and Kingston. Maestro (61 days) and Little Marvel (60 days) are the best shelling options for these cities. Avoid longer-season climbing varieties (Lincoln 65 days, Super Sugar Snap 65 days) in Ottawa — the season is too short for them to produce reliably before heat arrives.
Can I grow fall peas in Ontario?
Yes — sow Sugar Ann in mid-August for an October harvest in Toronto, Windsor, Hamilton, and London. Ottawa and Kingston can sow August 10–20, but the margin before October frost is tight. Fall peas in Ontario are more challenging than the spring crop — August heat and drought stress germinating seedlings. Keep soil consistently moist from sowing until emergence. Wando has the best heat tolerance for late-summer sowing. Fall peas in Ontario are never as reliable as coastal BC's fall crop, but they are a worthwhile second harvest in most years.
Should I use inoculant when planting peas in Ontario?
Yes, in new beds or beds that haven't grown peas or beans in 3–4 years. Rhizobium leguminosarum inoculant establishes the nitrogen-fixing root nodule relationship from the first roots — particularly useful in Ontario's cold April soil where natural bacterial activity is slow to start. Coat seeds with powder inoculant just before sowing, in the shade. In beds with a history of healthy legume crops, benefit is smaller but the cost is minimal.