When To Plant Watermelon In Louisiana

If you’re planning to grow watermelon in Louisiana, timing is everything. Knowing exactly when to plant watermelon in Louisiana is the first step to a succesful harvest.

The hot, humid climate is perfect for these juicy fruits, but you have to work with the seasons. Planting at the right time avoids late frosts and gives your vines the long, warm growing period they need. Let’s get your garden schedule sorted.

For most of Louisiana, the optimal planting window is from mid-March through early April. This timing is crucial for a few key reasons.

You want the soil to be thoroughly warm—at least 70°F—and all danger of a late frost must be past. Planting during this period allows the vines to establish before the intense summer heat arrives, yet ensures they fruit during the peak of summer warmth.

Understanding Louisiana’s Growing Zones

Louisiana spans USDA hardiness zones 8a to 10a. This affects your specific planting dates:

North Louisiana (Zones 8a-8b): Aim for early to mid-April. Wait until soil temperatures are consistently warm.
Central Louisiana (Zone 9a): The sweet spot is late March to early April.
South Louisiana (Zones 9b-10a): You can start earliest, from mid-March onward.

A simple soil thermometer is a great investment. Don’t rush planting into cool, wet soil; seeds will rot and transplants will struggle.

Succession Planting for Extended Harvest

To stretch your harvest season, consider planting in two waves. Plant your first batch in the main spring window. Then, plant a second, smaller succession about two weeks later.

This technique helps ensure you don’t get all your giant watermelons ripe at once. It also provides a backup in case an unexpected late cool snap affects your first planting.

Starting Seeds Indoors vs. Direct Sowing

You have two good options for getting started. Each has it’s advantages.

Direct Sowing: Simply plant seeds 1 inch deep directly in your garden hill or row after the last frost date. This is easiest and avoids transplant shock.
Starting Indoors: For a head start, sow seeds in biodegradable pots 3-4 weeks before your outdoor planting date. Transplant carefully to avoid disturbing roots.

If you start indoors, harden off seedlings for a week before putting them in the ground. This means gradually exposing them to outdoor sun and wind.

Choosing the Right Watermelon Varieties for Louisiana

Selecting varieties adapted to the Gulf South’s heat and humidity is half the battle. Look for disease resistance and a maturity date that fits your season.

Recommended Varieties

‘Crimson Sweet’: A classic, reliable variety with good disease resistance. Produces large, sweet fruits.
‘Charleston Gray’: Known for its tough rind and excellent heat tolerance. It’s a consistent performer.
‘Sugar Baby’ or ‘Black Diamond’: These are smaller, icebox types that mature quicker, around 75-80 days.
‘Jubilee’: A great oblong melon that does very well in Louisiana’s conditions.

Always check seed packets for days to maturity. Shorter-season varieties (under 85 days) are safer for north Louisiana, while the south can handle longer-season types.

Preparing Your Garden for Watermelon

Watermelons are heavy feeders and need space to roam. Proper site preparation makes a huge difference in plant health and yield.

Site Selection and Soil Preparation

Choose the sunniest spot in your garden—watermelons need a minimum of 8 hours of direct sun daily. The soil should be well-draining. Raised beds or mounded hills are ideal, especially in areas with heavy clay soil.

Prepare the soil by:

Working in 3-4 inches of compost or well-rotted manure.
Adding a balanced, slow-release fertilizer according to package directions.
Ensuring the soil pH is between 6.0 and 6.8.

Planting Layout and Spacing

Watermelon vines need room. Crowding leads to poor air circulation and disease.

Hills Method: Create mounds 3 feet high and 4 feet wide. Space the mounds 6-8 feet apart. Plant 3-4 seeds per hill, later thinning to the 2 strongest plants.
Rows Method: Space rows 6-8 feet apart. Space plants 2-3 feet apart within the row.

Using a trellis for smaller varieties is an option to save space, but you’ll need slings to support the heavy fruit.

Caring for Your Watermelon Plants

Consistent care through the season is key to sweet, plentiful fruit.

Watering and Fertilizing Schedule

Water deeply and consistently, providing 1-2 inches of water per week. Use drip irrigation or soaker hoses to keep foliage dry and prevent fungal diseases. The most critical watering periods are during fruit set and growth.

Reduce watering significantly in the last week or two before harvest. This concentrates the sugars for sweeter melons.

Side-dress with a fertilizer higher in potassium when vines begin to run, and again when fruits appear. To much nitrogen early on will give you all leaves and no fruit.

Weed and Pest Management

Mulch heavily with straw or pine straw around plants. This suppresses weeds, conserves moisture, and keeps fruit off the damp soil.

Common Louisiana pests include cucumber beetles, aphids, and squash vine borers. Inspect plants regularly. Use floating row covers early in the season, removing them when flowers appear so pollinators can get in.

For diseases like powdery mildew or fusarium wilt, choose resistant varieties and avoid wetting the leaves when you water. Crop rotation is also essential—don’t plant watermelons in the same spot year after year.

Pollination Tips

Watermelons have separate male and female flowers. Bees are vital for transferring pollen. If you notice few bees, you can hand-pollinate.

Simply pick a male flower, remove its petals, and gently brush the pollen-covered anther onto the stigma in the center of a female flower (the one with a tiny fruit at its base). Do this in the morning.

Knowing When to Harvest

Harvest time is the big reward. Picking at peak ripeness is an art. Here’s how to tell:

Check the Tendril: The curly tendril closest to the fruit stem turns brown and dries up when the melon is ripe.
Look at the Spot: The underside (where the melon touches the ground) changes from white to a creamy yellow.
Thump Test: A ripe melon often has a deep, hollow sound when thumped, though this method takes practice.
Check the Rind: The rind loses its glossy shine and becomes dull, and it becomes tough to pierce with a fingernail.

Use a sharp knife or pruners to cut the stem, leaving an inch attached. Handle carefully to avoid bruising.

Frequently Asked Questions (FAQ)

What is the latest you can plant watermelon in Louisiana?

For a fall crop, you can plant by late July to early August in south Louisiana. In northern parts, aim for early July. Use a short-season variety to ensure maturity before first frost.

Can I plant watermelon seeds from a store-bought melon?

It’s possible, but not recommended. Many commercial melons are hybrids, so seeds may not produce true to the parent. They also might not be adapted to local diseases. It’s better to buy seeds from a reliable supplier.

How long does it take for watermelons to grow?

From planting to harvest, most varieties take 80-100 days. Smaller “icebox” types can be ready in as little as 70 days. Always refer to the “days to maturity” on your seed packet.

Why are my watermelon vines flowering but not producing fruit?

This is often a pollination issue. Lack of bees, rainy weather, or high heat can limit pollination. Try hand-pollinating. Also, ensure your are not using to much nitrogen fertilizer, which promotes leafy growth over fruiting.

What should I plant next to watermelon?

Good companions include corn, radishes, and marigolds. Avoid planting them near potatoes or cucumbers, as they can compete for space and share similar pests.

With the right timing and care, growing watermelon in Louisiana can be a highly rewarding summer project. Paying close attention to your local frost dates, soil warmth, and variety selection sets you up for a season full of sweet, homegrown fruit. Remember, patience is key—wait for that ground to warm up, and your melons will thank you.