Growing Watermelon

Best Planting Times for Watermelons in Oklahoma

Planting MethodActivityRecommended Dates
Outdoor PlantingIndoor Seed StartingApril 15 – May 15
Transplant OutdoorsMay 15 – June 1
Greenhouse PlantingYear-roundAdjust planting based on temperature control in the greenhouse

Planting Conditions

Watermelon Planting Conditions

Oklahoma’s climate is characterized by hot summers and mild winters, making it ideal for watermelon growth but also bringing the need for proper planting conditions to avoid heat stress.

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Useful Tools for Starting Watermelons Indoors

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

Seeds

Quality seeds lead to better germination and healthier plants. Starting with high-quality watermelon seeds gives your crop 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 Oklahoma, where high temperatures can be a concern for watermelon growth, a greenhouse provides a stable and controlled environment. It can help protect plants from extreme heat, extend the growing season, and ensure optimal development with proper climate 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 Oklahoma, 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 Oklahoma approximately 1-2 weeks after the last spring frost date, ensuring the soil is warm enough for optimal growth.

Average Last Frost Dates for Oklahoma’s Major Cities

CityAverage Last Frost Date
Oklahoma CityApril 18
TulsaApril 24
NormanApril 12
Broken ArrowApril 23
EdmondApril 19
LawtonApril 25
MooreApril 18
Midwest CityApril 16
StillwaterApril 20
BartlesvilleApril 28

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 Oklahoma:

Broccoli Planting in Oklahoma

Pumpkin Planting in Oklahoma

Tomato Planting in Oklahoma

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

Starting Watermelons Indoors

In Oklahoma, it’s best to start watermelon seeds indoors between April 15 and May 15. This timing allows for healthy seedlings that can be transplanted outdoors once temperatures consistently exceed 70°F, typically by late May to early June.

Transplanting Watermelon Seedlings

Transplant watermelon seedlings outdoors after the last frost date, usually around June 1 to June 15. Ensure that the soil temperature is consistently above 70°F for optimal growth. Space seedlings 36-42 inches apart in rows that are 6-8 feet apart to provide ample room for the vines.

General Care and Maintenance

Watering

  • Watermelons require deep, consistent watering, especially during flowering and fruiting stages. Oklahoma’s hot climate demands regular water to maintain evenly moist soil.
  • Water at the base of plants to avoid wetting foliage and help prevent diseases common in humid environments.

Fertilizing

  • Utilize a balanced fertilizer during planting, and again when the first flowers develop, to support healthy growth. Adding compost can also improve soil fertility.

Pest and Disease Management

  • Regularly check for pests such as aphids, cucumber beetles, and diseases like powdery mildew. Oklahoma’s warm temperatures can foster pest populations.
  • Employ organic pest management strategies and encourage beneficial insects to protect your watermelon crops.

Harvesting

  • Harvest watermelons when they sound hollow when tapped and the tendril nearest the fruit turns brown. Regular harvesting encourages the growth of additional melons.

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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