How To Grow Watermelon In Minnesota

You can grow watermelon in Minnesota if you choose the right variety and give the plants a strong head start.
 
Minnesota has a shorter growing season than the traditional watermelon belt down south.
 
But that doesn’t mean growing watermelon in Minnesota is impossible.
 
It just means you need to be smart about which watermelon varieties you pick and when you plant them.
 
In this post, we’ll walk through how to grow watermelon in Minnesota from seed to harvest, including the best varieties, planting timing, and care tips that actually work in our climate.
 
Let’s dig in.

Why Growing Watermelon in Minnesota Takes Planning

Growing watermelon in Minnesota works best when you understand the state’s climate limitations.
 
Watermelons love heat and hate cold.
 
Most watermelon varieties need between 80 and 100 frost-free days to fully ripen.
 
Minnesota’s growing season typically runs from late May to early October.
 
That gives you somewhere between 120 and 150 days depending on where you live in the state.
 
Sounds like plenty of time, right?
 
The problem is that watermelons also need consistent warmth.
 
They don’t just need days without frost, they need soil temperatures above 70°F and air temperatures that stay warm both day and night.
 
In Minnesota, those conditions don’t really arrive until June.
 
That’s why growing watermelon in Minnesota requires choosing short-season varieties and starting seeds indoors.
 

Best Watermelon Varieties for Minnesota Gardens

The single most important decision when growing watermelon in Minnesota is variety selection.
 
Short-season watermelons are your best friend.
 
Here are some proven performers:
 

1. Sugar Baby

Sugar Baby is a classic icebox watermelon that matures in about 75 to 80 days.
 
It produces small, round melons that weigh around 8 to 10 pounds.
 
The flesh is sweet and deep red, and the rind turns dark green when ripe.
 
Sugar Baby is one of the most reliable choices for growing watermelon in Minnesota.
 

2. Black Tail Mountain

Black Tail Mountain was literally developed for short growing seasons.
 
It matures in roughly 70 to 75 days and handles cooler nights better than most.
 
The melons are round, dark green, and weigh about 10 to 15 pounds.
 
If you’re serious about growing watermelon in Minnesota, this variety should be on your list.
 

3. Crimson Sweet

Crimson Sweet takes about 85 days to mature.
 
It’s a bit longer than Sugar Baby, but it’s still doable in southern Minnesota.
 
The melons are larger, averaging 15 to 25 pounds, with bright red flesh and high sugar content.
 
Growing watermelon in Minnesota with Crimson Sweet works best if you start seeds early indoors.
 

4. Yellow Doll

Yellow Doll is another short-season option that matures in about 75 days.
 
It has yellow flesh and a sweet, mild flavor.
 
The melons are small, usually 5 to 8 pounds, making them easy to handle.
 

How to Plant and Care for Watermelon in Minnesota

Once you’ve picked your varieties, the next step is getting them in the ground at the right time.
 

1. Start Seeds Indoors

Begin your watermelon seeds indoors about 3 to 4 weeks before your last frost date.
 
In Minnesota, that’s usually around mid to late April.
 
Use peat pots or biodegradable containers because watermelons don’t like their roots disturbed.
 
Keep the seedlings warm, ideally between 75°F and 85°F, and give them plenty of light.
 

2. Harden Off Before Transplanting

Before you move your watermelon seedlings outside, harden them off over 7 to 10 days.
 
Start by placing them outdoors for just a couple of hours in a shaded spot.
 
Gradually increase their time outside and exposure to sun.
 
This step is critical when growing watermelon in Minnesota because cold shock can stunt or kill young plants.
 

3. Wait for Warm Soil

Don’t transplant until the soil temperature is at least 70°F.
 
In most of Minnesota, that means waiting until early June.
 
You can speed things up by laying black plastic mulch over your planting area a couple of weeks before transplanting.
 
The plastic warms the soil and gives your watermelons a better start.
 

4. Choose a Sunny Spot

Watermelons need full sun, at least 8 hours a day.
 
Pick the sunniest spot in your garden and make sure it drains well.
 
Watermelons hate soggy roots.
 
If your soil is heavy clay, amend it with compost before planting.
 

5. Water and Feed Consistently

Water your watermelon plants deeply once a week, giving them about 1 to 2 inches of water.
 
Avoid overhead watering to reduce the risk of disease.
 
Feed them with a balanced fertilizer early on, then switch to a low-nitrogen formula once flowers appear.
 
Too much nitrogen gives you lots of leaves but no fruit.
 

6. Use Row Covers Early On

Floating row covers can protect young watermelon plants from cool nights and pests.
 
Just remember to remove them once flowers appear so pollinators can get in.
 
Growing watermelon in Minnesota gets much easier when you give plants that extra warmth early in the season.
 

When to Harvest Watermelon in Minnesota

Harvest time depends on the variety, but most watermelons in Minnesota are ready between late August and mid-September.
 
Here’s how to tell when they’re ripe:
 
The tendril closest to the fruit turns brown and dries up.
 
The underside of the melon turns from white to creamy yellow.
 
The rind becomes dull instead of shiny.
 
And when you thump it, you hear a deep, hollow sound.
 
Don’t rush it.
 
Watermelons don’t ripen after picking, so once you cut them, that’s it.
 

So, Can You Grow Watermelon in Minnesota?

You can grow watermelon in Minnesota if you pick short-season varieties, start seeds indoors, and wait for warm soil before transplanting.
 
Growing watermelon in Minnesota isn’t as hard as it sounds.
 
With the right varieties like Sugar Baby or Black Tail Mountain, a sunny spot, and a little patience, you can absolutely harvest sweet, homegrown watermelon right here in the North Star State.
 
So grab your seeds, mark your calendar, and give it a shot this season.