Plants rated zone 4 or colder survive the harshest winters in Maine’s interior and give extra insurance in southern Maine’s zone 5. Hostas, daylilies, peonies, sedum and Siberian iris are among the hardiest.
- Plantain Lily (Hosta) — Hardy to zone 3.
- Daylily — Shrugs off cold winters.
- Peony — Lives for decades in the cold.
- Stonecrop — Tough through freeze and thaw.
- Iris — Siberian types are very hardy.
- Garden Phlox — Cold hardy summer color.
- Meadow Sage — Hardy and long blooming.
- Columbine — Native and cold tough.
- False Spirea (Astilbe) — Hardy in moist shade.
- Yarrow — Hardy to zone 3.
Acanthaceae 'Wild Petunia'
Ruellia humilis 'Wild Petunia'
from $11.99 · 1GAL
Alkanet 'Alexander's Great'
Brunnera 'Alexander's Great'
from $16.99 · 1GAL
- Deer resistant
- Long blooming
- Rabbit resistant
Alkanet 'Heartleaf (macrophylla)'
Brunnera 'Heartleaf (macrophylla)'
from $16.99 · 1GAL
- Deer resistant
- Long blooming
- Rabbit resistant
Alkanet 'Jack Frost'
Brunnera 'Jack Frost'
from $16.99 · 1GAL
- Deer resistant
- Long blooming
- Rabbit resistant
Alkanet 'Jack of Diamonds'
Brunnera 'Jack of Diamonds'
from $16.99 · 1GAL
- Deer resistant
- Long blooming
- Rabbit resistant
Alkanet 'Looking Glass'
Brunnera 'Looking Glass'
from $16.99 · 1GAL
- Deer resistant
- Long blooming
- Rabbit resistant
Alkanet 'Permafrost'
Brunnera 'Permafrost'
from $16.99 · 1GAL
- Deer resistant
- Long blooming
- Rabbit resistant
Alkanet 'Queen of Hearts'
Brunnera 'Queen of Hearts'
from $16.99 · 1GAL
- Deer resistant
- Long blooming
- Rabbit resistant
Alkanet 'Sea Heart'
Brunnera 'Sea Heart'
from $16.99 · 1GAL
- Deer resistant
- Long blooming
- Rabbit resistant
Alpinum 'Edelweiss'
Leontopodium 'Edelweiss'
from $6.99 · 1QT
Alyssum 'Basket of Gold (Compacta)'
Aurinia 'Basket of Gold (Compacta)'
from $6.99 · 1QT
Alyssum 'Mountain Gold'
Aurinia 'Mountain Gold'
from $6.99 · 1QT
Tips
- Southern Maine is mostly zone 5; inland and higher areas are zone 4.
- Snow cover insulates plants — a snowless cold snap does the most damage.
- Mulch new plantings after the ground freezes.
Frequently asked questions
What zone am I in?
Most of southern Maine is zone 5. Inland and northern areas are zone 4 or colder.
Can I grow zone 5 plants in zone 4?
Sometimes, in sheltered spots with good snow cover, but zone 4 plants are safer.
What kills plants in winter?
Freeze-thaw cycles, wet soil and cold without snow cover.
Should I mulch perennials for winter?
Mulch new plantings after the ground freezes to keep them from heaving.