Watermelon Planting Dates Arizona

Best Planting Times for Watermelon in Arizona

Planting Method	Activity	Recommended Dates
Outdoor Planting	Indoor Seed Starting	March 1 – April 15
	Transplant Outdoors	April 15 – May 15
Greenhouse Planting	Year-round	Adjust planting based on temperature control in the greenhouse

Planting Conditions

Arizona’s hot climate provides an ideal environment for watermelon cultivation, with ample sunlight and warm soil temperatures. However, maintaining consistent moisture and protection from extreme heat is crucial for successful growth.

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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.

Get 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.

Find Planting Trays on Amazon

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.

Check out Grow Lights on Amazon

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.

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Greenhouse Growing

In Arizona, where temperatures can soar, a greenhouse helps maintain optimal conditions for watermelon growth. It provides a controlled environment that minimizes heat stress, conserves moisture, and protects against pests, ensuring healthier and more productive plants.

Consider investing in a 10×12 FT Greenhouse (Now priced at $899) to ensure your watermelons thrive in a controlled environment.


Check the latest price on Amazon.

Fertilizer

For optimal watermelon growth in Arizona, supplementing with fertilizer can ensure abundant and healthy harvests. Quality fertilizer helps replenish nutrients in the soil and promotes vigorous plant growth.

Check out Fertilizer on Amazon

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Plant watermelons outdoors in Arizona approximately 1-2 weeks after the last spring frost date, ensuring the soil is warm enough for optimal growth.

Average Last Frost Dates for Arizona’s Major Cities

City	Average Last Frost Date
Phoenix	April 15
Tucson	April 30
Flagstaff	June 10
Yuma	April 1

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 Arizona:

Broccoli Planting in Arizona

Pumpkin Planting in Arizona

Any questions on Growing melons? Visit our forum to discuss: Growing melons.

Starting Watermelons Indoors

In Arizona, begin indoor watermelon seed starting between March 1 and March 15. This timeline ensures healthy seedlings ready for outdoor transplantation starting from mid-April to early May, allowing for optimal growth in the warm climate.

Transplanting Watermelon Seedlings

Transplant watermelon seedlings outdoors from April 15 to May 1, ensuring the soil has warmed above 70°F consistently. Space the seedlings 36-48 inches apart in rows with at least 6 feet between rows for optimal growth.

General Care and Maintenance

Watering

• Provide regular and deep watering to keep the soil consistently moist, especially during the hot Arizona summer months.
• Water at the base of the plants to avoid leaf wetness, minimizing the risk of fungal diseases.

Fertilizing

• Apply a balanced fertilizer during planting and again when the first fruits start forming. Incorporating organic matter into the soil can enhance fertility.

Pest and Disease Management

• Regularly monitor for common pests like aphids, cucumber beetles, and powdery mildew. The dry heat of Arizona can affect pest populations, but vigilance is key.
• Utilize organic or integrated pest management methods to protect watermelon plants from pests and diseases.

Harvesting

• Harvest watermelons when they are fully ripe, indicated by a yellow spot on the bottom and a dull sound when tapped. Regular harvesting ensures optimal quality and sweetness.

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 🙂