How To Grow Watermelon In Minnesota

You can grow watermelon in Minnesota, and plenty of gardeners do it successfully every summer with the right variety and a few smart tricks.
 
Minnesota has a short growing season, but that doesn’t mean you have to give up on sweet, homegrown watermelon.
 
If you’ve been wondering how to grow watermelon in Minnesota, the answer comes down to choosing fast-maturing varieties, starting seeds early, and keeping those vines warm.
 
In this post, we’ll walk through how to grow watermelon in Minnesota step by step, from picking the right seeds to knowing exactly when to harvest.
 
Let’s dig in.
 

How to Grow Watermelon in Minnesota: The Basics

Growing watermelon in Minnesota starts with understanding what this warm-weather crop actually needs.
 
Watermelons love heat, sun, and plenty of space, and Minnesota’s cool nights and short season mean you have to work a little harder than a gardener in Georgia.
 
The good news is that growing watermelon in Minnesota is absolutely doable when you stack the odds in your favor.
 

1. Pick a Short-Season Variety

The single most important step when you grow watermelon in Minnesota is choosing a variety that matures fast.
 
Look for watermelons that ripen in 70 to 85 days, like Sugar Baby, Blacktail Mountain, Cream of Saskatchewan, or Yellow Doll.
 
These shorter-season types were bred for cooler climates, so they’ll actually finish before the first frost sneaks in.
 
If you try to grow a 100-day giant watermelon in Minnesota, you’ll likely end up with a lot of vine and no fruit.
 

2. Start Seeds Indoors

Because Minnesota’s growing season is short, you should start watermelon seeds indoors about three to four weeks before your last frost date.
 
In most parts of Minnesota, that means sowing seeds in late April or early May.
 
Use peat pots or biodegradable containers so you can transplant without disturbing the roots, since watermelons hate being moved.
 
Keep your seedlings warm, around 75 to 80°F, and give them plenty of light so they grow strong before they head outside.
 

Planting Watermelon in Minnesota

Once the soil warms up, it’s time to get those vines in the ground.
 
Timing and location make all the difference when you plant watermelon in Minnesota.
 

1. Wait for Warm Soil

Don’t rush your watermelon into cold ground.
 
Watermelons need soil temperatures of at least 60°F, and ideally closer to 70°F, before they’ll grow well.
 
In Minnesota, that usually means waiting until late May or early June, once the danger of frost has passed.
 
Planting too early can stunt your vines or kill them outright.
 

2. Choose a Sunny Spot

Watermelons need full sun, at least eight hours a day, so pick the sunniest spot in your yard.
 
A south-facing slope or a spot near a warm wall works great because it holds heat.
 
Good drainage matters too, since watermelons rot if their roots sit in soggy soil.
 

3. Warm the Soil With Black Plastic

Here’s a trick that Minnesota gardeners swear by.
 
Cover your planting area with black plastic mulch a week or two before transplanting.
 
The plastic absorbs heat and warms the soil, giving your watermelons a head start in Minnesota’s cool climate.
 
Cut holes in the plastic and plant right through it.
 

Caring for Watermelon in Minnesota

Once your vines are growing, a little care goes a long way toward a sweet harvest.
 
Keeping watermelon healthy in Minnesota means managing water, nutrients, and warmth.
 

1. Water Consistently

Watermelons need steady moisture, especially while the fruit is swelling.
 
Give them about an inch of water per week, and water deeply at the base rather than spraying the leaves.
 
Consistent watering prevents blossom end rot and keeps the fruit from splitting.
 

2. Feed Lightly

Watermelons aren’t heavy feeders, but they do appreciate a boost.
 
Mix some compost into the soil before planting, then side-dress with a balanced fertilizer when the vines start running.
 
Too much nitrogen gives you leafy vines and fewer melons, so don’t overdo it.
 

3. Protect Against Cool Nights

Minnesota nights can get chilly even in summer, and watermelons slow down when temps drop.
 
Use row covers or floating fabric to trap warmth early in the season, then remove them once flowers appear so pollinators can get in.
 

4. Hand-Pollinate if Needed

Bees usually handle pollination, but cool or rainy weather can keep them away.
 
If your vines are flowering but not setting fruit, try hand-pollinating by transferring pollen from male to female flowers with a small brush.
 

Harvesting Watermelon in Minnesota

Knowing when to pick your watermelon is the final piece of the puzzle.
 
In Minnesota, most watermelons ripen in late August or early September, before the first frost.
 
Look for a dried, brown tendril near the stem, a dull thud when you tap it, and a creamy yellow spot where the melon rested on the ground.
 
Once it’s ripe, cut it from the vine and enjoy it right away, because homegrown watermelon in Minnesota tastes sweeter than anything from the store.
 

So, Can You Grow Watermelon in Minnesota?

You can grow watermelon in Minnesota, and with the right variety, timing, and a little warmth, you’ll be rewarded with sweet, juicy fruit.
 
Growing watermelon in Minnesota comes down to picking short-season types, starting seeds indoors, warming the soil, and protecting your vines from cool nights.
 
Follow these steps and you’ll be harvesting your own watermelon in Minnesota before the season ends.
 
Happy growing.