What to Plant in August in Zone 3
Here is what you can sow in August if you garden in USDA zone 3. Dates use typical zone 3 frosts, so your own microclimate may shift them by a week or two.
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| Crop | Window | Sow between |
|---|---|---|
| Squash, winterWaltham Butternut | spring | Jun 21 – Aug 5 |
| PumpkinNew England Pie | spring | Jul 5 – Aug 20 |
| Sweet PotatoBeauregard | spring | Jun 21 – Aug 5 |
| CilantroCalypso | fall | Jul 2 – Aug 15 |
| Lettuce, leafSalad Bowl | fall | Jul 2 – Aug 31 |
| Lettuce, romaineChalupa | fall | Jul 2 – Aug 31 |
| Lettuce, headButtercrunch | fall | Jul 2 – Aug 15 |
| SpinachBloomsdale | fall | Jul 2 – Aug 20 |
| ArugulaAstro | fall | Jul 2 – Aug 31 |
| Mustard GreensFlorida Broadleaf | fall | Jun 20 – Aug 1 |
| RadishCherry Belle | fall | Jul 2 – Aug 15 |
| Onion, bulbTexas Legend | fall | Jul 21 – Sep 1 |
| Bok ChoyJoi Choi F1 | fall | Jun 27 – Aug 6 |
| Rapini (Broccoli Raab)Zamboni F1 | fall | Jun 22 – Aug 1 |
| TatsoiTatsoi | fall | Jun 22 – Aug 6 |
| MizunaMizuna Early | fall | Jun 27 – Aug 11 |
| Daikon RadishMiyashige | fall | Jun 27 – Aug 6 |
| SorrelProfusion | fall | Jul 2 – Aug 16 |
| WatercressCommon | fall | Jul 2 – Aug 16 |
| Strawberry, day-neutralAlbion | fall | Jul 17 – Aug 16 |
| DillFernleaf | fall | Jul 14 – Aug 25 |
| MarjoramSweet Marjoram | spring | May 29 – Aug 7 |
| ChervilCurled | fall | Jul 21 – Sep 1 |
| Summer SavoryCommon | spring | May 29 – Aug 7 |
| Strawberry, June-bearingHoneoye | fall | Jul 17 – Aug 16 |
| Lettuce | fall | Jul 2 – Aug 31 |
| Onion | fall | Jul 21 – Sep 1 |
| Calendula (Pot Marigold)Resina | fall | Jul 2 – Aug 15 |
| Mache (Corn Salad)Vit | fall | Jul 17 – Sep 5 |
| Cress, gardenCurled | fall | Jul 2 – Aug 31 |
Zone 3 in August
August in Zone 3: Prepping Cover Before You Need It
Build or set up the season-extension gear now, not in September
Cold frames, low tunnels, and hoop covers all take an hour or two to build or repair, and doing that work now, while weather is still mild, beats scrambling to build one the week frost threatens next month. A basic low tunnel needs only wire hoops set every 3 feet and a layer of clear plastic or heavy row cover pulled over the top.
Test the cover on a warm afternoon before you actually need it for cold protection. Slide a thermometer under the plastic at midday and set a second one out in the open nearby for comparison: a tunnel that reads noticeably hotter than the open-air number on a mild 70 degree day is trapping enough heat to stress or scorch the same greens you are trying to protect from frost a month later.
Prepare the garlic bed while the summer crop still occupies half the garden
Garlic goes into the ground next month, which means the bed needs clearing and amending now. Pull any spent squash or bean vines that have stopped producing, spread 2 to 3 inches of compost and rake it into the surface, then let the bed rest for 2 to 3 weeks before planting cloves.
Sow one more fast round of radish or a baby greens mix into any freed space this week. Anything under 30 days to maturity still has a real shot at finishing before the season-ending cold arrives in force.
Keep the low tunnel materials stacked somewhere accessible, not stored deep in the back of a shed. A frost warning here can arrive with only 2 or 3 days of notice, and gear you have to dig for is gear that does not get used in time.
August in zone 3: common questions
What can I plant in August in zone 3?+
In August, USDA zone 3 gardeners can sow Squash, winter, Pumpkin, Sweet Potato, Cilantro, Lettuce, leaf, Lettuce, romaine, and more. Dates use typical zone 3 frosts, so your own microclimate may shift them by a week or two.
What USDA hardiness zone am I in?+
Zone 3 is one band of the map, but planting time is set by your local frost dates, not the zone number. Enter your ZIP code in the free planner and it uses your actual frost dates, which can differ by weeks within a single zone.
Are these August planting dates exact?+
They are typical zone 3 windows. Two gardens in the same zone can be a week or two apart because of elevation and local climate, so treat these as a starting point and tune them to your ZIP code with the free planner.