Knowing what to plant is only half the battle — knowing when to plant is what separates a productive garden from a frustrating one. Plant tomatoes too early and frost kills them. Plant lettuce too late and heat bolts them before you harvest.
This month-by-month guide covers US hardiness zones 5–8, which includes most of the continental United States — from the Midwest and Mid-Atlantic through the South and Pacific Coast.
Zones 3–4 (northern US/Canada): shift everything 3–4 weeks later. Zones 9–10 (southern US/Florida): shift everything 3–4 weeks earlier and look up specific warm-climate guides for your area.
January: Plan and Order Seeds
Nothing grows outside in January for most zones, but this is the most important month for your garden season. Seed companies sell out of popular varieties early — order by late January.
This month:
- Decide what you’re growing this year (see our best vegetables for ROI guide)
- Order seeds online or buy at garden centres
- Plan your garden layout — what goes where
- Gather supplies: seed trays, potting mix, grow lights (if starting seeds indoors)
February: Start Seeds Indoors (Zones 6–8)
Zone 5: start 2–3 weeks later. Zone 4: start in March.
Start indoors this month:
- Peppers — need 8–10 weeks indoors before last frost date
- Eggplant — same as peppers
- Onions from seed — slow growers, need early start
- Celery — very slow, needs 10–12 weeks
What you’re doing: Set up seed trays under grow lights or in a south-facing window. Keep soil moist but not wet. Germination temperature for peppers and eggplant: 75–85°F (use a heat mat).
March: Tomatoes and Early Outdoor Sowing
Start indoors this month:
- Tomatoes — 6–8 weeks before your last frost date
- Basil — 4–6 weeks before last frost
- Annual herbs — cilantro, dill, parsley
Direct sow outdoors (cold-hardy crops):
- Peas — can handle light frost, sow 4–6 weeks before last frost
- Spinach — cold-tolerant, sow as soon as soil can be worked
- Carrots — slow germination, sow early
- Beets
Garden prep: Add compost to beds if you haven’t already. Clean up winter debris.
April: Peak Indoor Growing + First Outdoor Planting
Your indoor seedlings are growing fast. Tomatoes and peppers need potting up if roots are escaping drainage holes.
Outdoors (after soil temperature reaches 45°F+):
- Lettuce and salad mix — direct sow or transplant
- Kale and Swiss chard
- Broccoli and cabbage transplants
- More peas and spinach
- Potatoes — plant seed potatoes when soil is consistently above 45°F
Hardening off: Start taking indoor seedlings outside for a few hours per day to acclimate to outdoor conditions. Do this for 1–2 weeks before transplanting.
May: Main Planting Month (After Last Frost)
This is the most important planting month for most zones. After your last frost date, the main vegetable season begins. Find your last frost date at planthardiness.ars.usda.gov.
Transplant outdoors after last frost:
- Tomatoes — your indoor seedlings go in the ground
- Peppers and eggplant
- Basil (warm-weather herb, frost-sensitive)
Direct sow outdoors:
- Zucchini and summer squash — direct sow after frost, germinate in 5–7 days
- Cucumbers
- Green beans — direct sow every 2–3 weeks for succession harvest
- Winter squash and pumpkins
May is also when you set up support structures: tomato cages, bean poles, cucumber trellises.
June: Early Summer — Maintenance and First Harvests
Harvest:
- Lettuce and salad greens (before they bolt)
- Peas
- Spinach (last harvest before summer heat)
- Herbs: continuous harvest
- Early zucchini (harvest when small for best flavour)
Plant:
- Succession sow beans every 2–3 weeks
- Plant heat-tolerant lettuce varieties for summer (Jericho, Nevada, Summer Crisp)
- Sow more herbs to replace any that bolt
Maintenance:
- Mulch beds to retain moisture (reduces watering by 30–50%)
- Stake tomatoes as they grow
- Watch for pest pressure (aphids, cucumber beetles)
July: Peak Growing Season — Heaviest Harvests
Harvest:
- Tomatoes (first fruits appear in late July for most zones)
- Zucchini — pick every 2–3 days to prevent marrows
- Cucumbers — harvest frequently for continuous production
- Beans
- Herbs: continuous
Plant:
- Sow more beans for fall harvest
- Start broccoli and kale seedlings indoors for fall planting
- Sow carrots for fall harvest
Preservation: July is when the surplus starts. Freeze tomatoes whole, make zucchini bread, dry herbs.
August: Late Summer Harvests + Fall Garden Prep
Harvest:
- Tomatoes — peak harvest month
- Peppers
- Cucumbers
- Beans
- Early winter squash varieties
Plant:
- Transplant broccoli and kale seedlings outdoors (fall crop)
- Direct sow spinach and lettuce for fall harvest
- Direct sow radishes (fastest vegetable — 25 days to harvest)
September: Fall Harvest Season
Harvest:
- Last tomatoes (harvest all before first frost)
- Winter squash and pumpkins (cured and stored)
- Potatoes (dig before ground freezes)
- Fall broccoli and kale
- Peppers — harvest all before frost
Plant:
- Garlic — plant in September/October for harvest next summer (highest-ROI late planting)
- Cold-hardy greens (kale, spinach, arugula)
October: Garlic and Garden Closing
Final harvests: Kale, chard, and root vegetables that survived light frosts. Kale tastes sweeter after frost — don’t rush to pull it.
Plant: Garlic — the most satisfying fall planting. Put individual cloves in the ground 4–6 inches deep. They overwinter and emerge in spring, ready to harvest in July.
Garden closing:
- Add compost to beds (let it break down over winter)
- Pull spent plants and add to compost pile
- Save seeds from heirloom tomatoes, beans, and squash for next year (free seeds!)
- Note what worked and what didn’t — your most valuable planning tool
Seed Saving: Eliminate Your Seed Cost for Year 2+
Open-pollinated and heirloom varieties produce seeds that grow true to type — meaning you can save and replant them indefinitely. Seed saving from tomatoes, beans, peas, and squash is straightforward and eliminates $15–$30/year in seed costs.
To get started with a diverse seed collection: See heirloom non-GMO seed collections on Amazon.