Saving Heirloom Peas from Cutworms in Northern Ontario

Protecting a Family Legacy

A gardener in Northern Ontario grows heirloom peas (from Spain, post-WWI) saved 40+ years. This year, cutworms decimated seedlings. Devastated, she asks: replant? prevent next year?

Can You Replant Now?

Yes, if summers are mild. Peas prefer cool weather (55–65°F). In Northern Ontario, a late May/early June planting for fall harvest may work. Risk: heat during flowering reduces yield. But losing the seed line is worse.

Cutworm Prevention for Replanting

1. Collars (Most Reliable)

• Cardboard tubes (toilet paper rolls, cut lengthwise) or 3" wide strips taped into cylinders.
• Push 1" into soil around each seedling.
• Blocks cutworms from reaching stem.

2. Onion Spray Deterrent

• 1 large onion + 1/2 cup water → blend
• Strain into spray bottle
• Spray soil around plants daily

3. Beneficial Nematodes

• Steinernema carpocapsae – apply to moist soil at dusk; targets cutworm larvae.

4. Cultural Practices

• Remove weeds/grass 2 weeks before planting – eliminates alternate hosts.
• Fall tillage exposes pupae to cold/predators.
• Encourage birds (robins, blackbirds) – major cutworm predators.

Chemical Option (Last Resort)

Carbaryl (Sevin) – effective but kills beneficials. Use only if organic methods fail. Follow label exactly.

Long-Term Seed Stewardship

• Save seed from multiple plants each year (genetic diversity).
• Store cool, dry, airtight (freezer best).
• Share with seed libraries/other gardeners – backup against loss.

Bottom Line

Replant now with collars + nematodes. Next year: collars from day one, fall tillage, bird habitat. Your family's peas are worth the effort.