Zone 3 · Herbs Growing Guide

When to Plant Mint
in Zone 3

Incredibly vigorous — grows in a container or it will take over your garden. Plant it in a buried pot or raised bed with barriers. Perennial in most zones. Harvest before flowering for best flavour.

Plant window opens
May 15
Last chance to plant
Jun 01
Last frost
~May 15
Days to harvest
90–120 days
Difficulty
Easy
Wrong season — Zone 3
Harvest: Jun – Oct

Planting Calendar

In Zone 3, Mint can be planted outdoors from May 15 — the window closes around Jun 01.

Perennial in Zone 3. Dies back in winter, returns reliably every spring. Contain in pots.

Get notified when to plant, water, and harvest your Mint — personalized for your zone.
What Zone 3 growers say about Mint
plant team · Zone 3
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Care Guide

Sunlight
Partial shade to full sun · 3–8 hrs/day
Watering
Regular
Spacing
18–24 inches
Soil
Rich, moist, well-draining
Days to maturity
90–120 days
Soil pH
6.0–7.0
Plant tip · Zone 3
Perennial in Zone 3. Dies back in winter, returns reliably every spring. Contain in pots.
Lifecycle
Perennial
How to know it's ready
Pick stems just before flowering for maximum flavour. Harvest regularly to prevent spreading.

Watering Mint

How often
Every 2–3 days — mint likes moisture
How much
1–1.5 inches per week
Method
Either method
Overwatering signs
Root rot, yellowing
Underwatering signs
Wilting, dry crispy leaves

Feeding Schedule

How often
twice a season
Feed type
Balanced fertilizer (light)
Key timing
spring and midsummer
NPK: 10-10-10 once or twice per season

Vigorous grower that rarely needs much feeding. Two feeds a year is plenty. Grow in containers to prevent spreading.

Example product: Espoma Herb-Tone
Reminder: every 42 days after feeding

Seasonal Care

Oct
Cut Back
Cut back hard to 2 inches in fall to prevent woodiness. Divide and replant every 2–3 years to refresh. Contains roots to prevent spreading.
Division
Easiest from cuttings or division — mint seeds are unreliable. Grow in containers to prevent spreading.
Container friendly · Minimum 1 gallons
Containers are the preferred way to grow mint — it spreads aggressively in the ground. Any size pot.

Companion Planting for Mint

What you plant near mint makes a real difference — here's what to plant, when, and why.

Pest deterrent
Brassicas
Deters cabbage moth and aphids
Plant at same time
Tomatoes
Repels aphids — keep mint in pots to control spread
Plant at same time
Keep away from
Parsley — Inhibit each other

Pests & Diseases

Know what to look for before it gets out of hand — early identification is the most important step.

What to look for
Clusters of tiny soft insects on new growth and leaf undersides. Leaves curl, yellow, or become sticky with honeydew. Sooty black mold may follow.
Cause
Multiple aphid species. Populations explode rapidly in warm weather.
Organic treatment
Blast off with strong water jet. Apply insecticidal soap or neem oil directly to colonies. Introduce ladybugs or lacewings.
Prevention
Plant marigolds and nasturtiums nearby. Avoid excess nitrogen fertilizer which creates soft, aphid-attractive growth. Encourage beneficial insects.
What to look for
Metallic striped beetles eating leaves and flowers. Most active autumn and spring.
Cause
Chrysolina americana. Affects lavender, rosemary, sage, thyme, marjoram.
Organic treatment
Hand-pick adults and larvae. Shake over a sheet. Pyrethrum spray.
Prevention
Check plants regularly. Avoid hiding spots at base.
What to look for
White coating on leaves. Leaves yellow and drop. Common on sage and mint.
Cause
Various Erysiphe fungi.
Organic treatment
Remove affected leaves. Improve airflow. Neem oil spray.
Prevention
Water at soil level. Ensure good spacing.

Recommended Varieties

  • Spearmint (classic)
  • Peppermint (strongest flavour, best for tea)
  • Apple Mint (mild, woolly leaves)
  • Chocolate Mint (dessert flavour)
  • Mojito Mint (large leaves, cocktails)
Grow each variety in its own container — mint varieties cross-pollinate and lose their character when mixed.
Crop Rotation — rotate every 0 years
Perennial — no annual rotation
Avoid planting after: N/A — permanent planting
Good to follow: N/A — permanent planting
Fruit trees and perennial shrubs are permanent plantings — crop rotation does not apply. Choose the planting site carefully as it is permanent.

Storing Your Harvest

Room temp
3–5 days in a glass of water like flowers
Fridge
1 week wrapped in damp paper towel
Freezer
Blanch briefly, freeze on a tray, bag — or make mint oil cubes
Mint dries well — hang bunches upside down for 2 weeks for long-term storage.

Free app · Kickstarter October 2027 · iOS February 2028

Know exactly when to plant, prune, and harvest Mint

plant uses your ZIP code and real frost data to tell you the right day — not just the right month. Get notified when your planting window opens, when to succession sow, and when to cut back for next season.

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Common questions

In Zone 3, direct sow mint outdoors May 15 – Jun 1 after your last frost of approximately May 15. Perennial in Zone 3. Dies back in winter, returns reliably every spring. Contain in pots.
Zone 3 has an average last spring frost around May 15 and a first fall frost around Sep 15. These vary by location — the plant app uses your ZIP code with NOAA data for precision.
Good companions for mint include Brassicas, Tomatoes. Avoid planting near Parsley.
Mint typically takes 90–120 days to harvest in Zone 3. Expected harvest window: Jun – Oct.

These guides get better when growers share what they know. If something's off or you've learned something worth passing on, add it here — accepted tips earn you a Founding Grower badge when plant launches.

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Mint in other zones
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