Growing Watermelon

Best Planting Times for Watermelons in Michigan

Planting MethodActivityRecommended Dates
Outdoor PlantingIndoor Seed StartingMay 1 – June 1
Transplant OutdoorsJune 15 – July 1
Greenhouse PlantingYear-roundAdjust planting based on temperature control in the greenhouse

Planting Conditions

Watermelon Planting Conditions

Michigan’s climate features cold winters and warm summers with USDA Hardiness Zones ranging from 5a to 6b. For watermelon cultivation, it is essential to consider the growing season and soil temperature to maximize yields.

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Useful Tools for Starting Watermelons Indoors

Using the right tools can save you time and increase your success rate.

Seeds

Quality seeds lead to better germination and healthier plants. Starting with high-quality seeds gives your watermelons the best chance to thrive from the very beginning.
5 pack of different Melon Seeds
Browse Watermelon Seeds on Amazon

Planting Trays

Planting trays help you organize your seedlings and ensure they have enough space to grow before you transplant them outdoors. This makes the process more efficient and increases the chances of strong, healthy plants.
Planting Trays Image
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Grow Lights

Grow lights are essential if you don’t have enough natural sunlight. They provide your seedlings with the light they need to grow strong and healthy, even in less-than-ideal conditions.
Grow Lights Image
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Seed Starting Soil

Using light, fine soil specifically designed for seed starting helps young roots establish quickly and promotes healthy growth. It’s an easy way to give your seedlings the best start possible.
Seed Starting Soil Image
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Greenhouse Growing

In Michigan, where spring temperatures can be unpredictable and short, a greenhouse provides a stable environment for optimal watermelon development. Greenhouses protect plants from unexpected frost, extend the growing season, and allow for better disease management.

Consider investing in a 10×12 FT Greenhouse priced at $1,199 to ensure your watermelons thrive in a controlled environment.
Greenhouse Image 1
Greenhouse Image 2
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Fertilizer

For optimal watermelon growth in Michigan, supplementing with fertilizer can ensure abundant and healthy harvests. Quality fertilizer helps replenish nutrients in the soil and promotes vigorous plant growth.
Fertilizer Image
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Plant watermelons outdoors in Michigan approximately 1-2 weeks after the last spring frost date, ensuring the soil is warm enough for optimal growth.

Average Last Frost Dates for Michigan’s Major Cities

CityAverage Last Frost Date
DetroitMay 18
Grand RapidsMay 16
Ann ArborMay 15
LansingMay 18
FlintMay 20
SaginawMay 22
KalamazooMay 20
Battle CreekMay 24
Traverse CityMay 28
MidlandMay 23

Disclaimer: Frost dates are average estimates, and actual conditions may vary. It is recommended to monitor local forecasts and adapt planting decisions accordingly.

Other Planting Guides for Michigan:

Broccoli Planting in Michigan

Pumpkin Planting in Michigan

Tomato Planting in Michigan

Any questions on growing watermelons? Visit our forum to discuss: Watermelon Growing Forum.

Starting Watermelon Indoors

In Michigan (Zone 5b), begin indoor watermelon seed starting between April 15 and May 15. This timeline ensures healthy seedlings ready for outdoor transplantation starting from late May to early June once the risk of frost has passed.

Transplanting Watermelon Seedlings

Transplant watermelon seedlings outdoors from June 1 to June 15, ensuring the soil has warmed above 65°F consistently. Space the seedlings 24-36 inches apart in rows with at least 48 inches between rows for optimal growth.

General Care and Maintenance

Watering

  • Provide consistent and deep watering to maintain evenly moist soil. Michigan’s varying climate necessitates regular watering, especially during active growth periods.
  • Water at the base of plants to avoid leaf wetness, reducing the risk of fungal diseases.

Fertilizing

  • Apply a balanced fertilizer during planting and when the first fruits start forming. Incorporating compost before planting can enhance soil fertility and structure.

Pest and Disease Management

  • Regularly monitor for common pests like aphids, cucumber beetles, and powdery mildew. In Michigan, pests can vary, so vigilance is essential.
  • Implement organic or integrated pest management methods to protect watermelon plants from pests and diseases.

Harvesting

  • Harvest watermelons when they reach the desired size and the tendril nearest the fruit turns brown. Regular harvesting promotes continued fruiting.

The importance of good soil

Before starting to grow it is important to take a step back and find the condition of the soil in your garden,The optimal soil is a blend that includes the mineral-rich dirt along with organicrich organic matter that plants need to thrive.


In my garden I try to compost as mutch as possible, so I can mix in the nutrient ritch compost in my soil. I use both hot composting of food scraps and cold composting of all organic garden “waste”..
If you dont have the time or space for composting, it is possible to get compost ready to use in garden centers and Community Composting.
You can read more on Community Composting here: https://www.epa.gov/sustainable-management-food/community-composting

If you are uncertain of the quality of your soil, you can get easy to use soil tests at amazon for 17 dollars. Check latest prices here: Soil testing kit.

Also remember to check out how much sunlight your growing area gets, and that the rain drains well. If you treat your soil well and plan you crops according to your climate you will succeed with any plant you want.

The satisfaction when you harvest your own produce is well worth the time you put in 🙂

BeeJay
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