When to Plant in Ann Arbor, MI

Ann Arbor, Michigan, experiences a median last spring frost on April 28 and a median first fall frost on October 15, providing approximately 170 frost-free days during the growing season. This substantial frost-free period allows gardeners to cultivate a diverse array of vegetables and flowers, ensuring ample opportunity for planting various crops throughout the warm months. The climate's specifics, such as well-defined seasons, significantly influence what can be grown successfully.

The microclimate in Ann Arbor is classified as humid continental (4 distinct seasons), which means that gardeners can expect both hot summers and cold winters. This climate type is advantageous for growing a variety of fruits and vegetables, particularly cool-season crops like kale and broccoli, which thrive in the cooler spring and fall months. However, heat-loving crops like eggplant and cucumbers might struggle if they are planted too late in the season, as the growing window for these plants can be cut shorter by the early frost on October 15.

What to plant now in Ann Arbor

Spring: From mid-March to late April, consider planting cool-season crops such as peas, lettuce, and radishes, as they can be sown before the last frost date of April 28.
Summer: Early June to mid-July is the ideal time to plant warm-season crops like tomatoes, peppers, and squash, given the frost-free days following April 28.
Fall: Mid-August through early September is great to plant fall greens like spinach and arugula, which can mature before the impending frost on October 15.
Winter: Late November to early December is a great time for planning your winter garden or starting seeds indoors for the upcoming spring season.

In Ann Arbor (170 frost-free days, a moderate season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.

Month by month in Ann Arbor

Month	What to do
January	January is a time for preparation. Review your garden plans, order seeds for the year, and prepare tools for the upcoming spring planting season.
February	In February, focus on starting seeds indoors for early varieties of vegetables, such as onions and leeks, to be ready for transplanting once the frost has safely passed.
March	As March arrives, prepare garden beds by clearing debris and tilling soil. Start sowing cool-season crops indoors and prepare for outdoor planting in late March.
April	April is crucial for early garden planting. By April 28, sow peas, spinach, and radishes directly in the garden as the last frost date approaches.
May	In May, after the last frost date has passed, plant warm-season crops like tomatoes, peppers, and beans. This is also a great time to transplant your previously started seedlings.
June	Summer begins in June, and it’s time to tend to your warm-season crops. Regular watering and mulching help in the maintenance of your plants during the hot weather.
July	Keep an eye on watering during the hot July days. This is the time to harvest early crops and consider planting a second round of beans or other quick-growing varieties.
August	In August, plan for a fall garden. Start sowing cool crops like kale and spinach to ensure they grow well before the first frost date of October 15.
September	September is a critical month to harvest remaining summer crops while planting fall vegetables. Monitor the temperature closely as October approaches.
October	As October unfolds, prepare for the first fall frost on October 15. Finish harvesting any mature crops and consider covering sensitive plants as temperatures drop.
November	In November, focus on garden cleanup and preparation for winter. It's essential to remove remnants of harvested crops to prevent pests and diseases.
December	December is a time to rest and plan for the upcoming year. Reflect on the past season’s successes and failures while reviewing what to plant in spring.

Frost dates for Ann Arbor ZIP codes

ZIP	Last spring frost (50%)	First fall frost (50%)	Zone
48103	April 28	October 15	6a
48105	April 28	October 15	6a
48109	April 28	October 15	6a

FAQ

When is the last frost in Ann Arbor?

The last frost in Ann Arbor typically occurs around April 28, allowing gardeners to plan their planting schedule accordingly.

What vegetables grow best in Ann Arbor?

In Ann Arbor, cool-season crops like kale, broccoli, and peas thrive well due to the humid continental climate, which allows for a longer growing season.

When should I plant tomatoes in Ann Arbor?

Tomatoes should be planted after the danger of frost has passed, ideally starting in mid-May, around 2-3 weeks after the last frost date of April 28.

Can I garden year-round in Ann Arbor?

Gardening year-round in Ann Arbor is challenging due to its harsh winters; however, using techniques such as cold frames or growing indoors can extend the gardening season.

How does Plan My Garden help Ann Arbor gardeners?

Plan My Garden provides specific information on planting timings, frost dates, and suitable plant varieties tailored for Ann Arbor's unique localization and climatic conditions.