How To Grow Watermelon In Colorado

You can grow watermelon in Colorado successfully if you choose the right varieties, use season extenders, and plant at the right time.
 
Watermelons love heat and long sunny days, which Colorado has plenty of during the summer.
 
The tricky part is our short growing season and unpredictable spring cold snaps, especially along the Front Range and higher elevations.
 
But with a few smart strategies, growing watermelon in Colorado is absolutely doable.
 
In this post, we will walk through how to grow watermelon in Colorado, from picking short-season varieties to harvesting sweet, juicy fruit.
 
Let’s dig in.
 

How to Grow Watermelon in Colorado: The Basics

Growing watermelon in Colorado starts with understanding what watermelons actually need to thrive.
 
These plants want full sun, warm soil, consistent moisture, and about 80 to 100 days of frost-free weather depending on the variety.
 
That’s why growing watermelon in Colorado takes a bit more planning than in places like Georgia or Texas.
 

1. Choose Short-Season Watermelon Varieties

The single most important step when growing watermelon in Colorado is picking a variety that matures fast.
 
Look for types that ripen in 70 to 85 days, such as Sugar Baby, Blacktail Mountain, Cream of Saskatchewan, or Yellow Doll.
 
These shorter-season watermelons give you the best shot at ripe fruit before the first fall frost.
 

2. Wait Until the Soil Is Warm

Watermelon seeds and transplants hate cold soil.
 
In Colorado, don’t plant until soil temperatures reach at least 65°F and all danger of frost has passed.
 
Along the Front Range, that usually means late May to early June.
 
In higher mountain areas, you might need to wait even longer or grow watermelons in a greenhouse or high tunnel.
 

3. Start Seeds Indoors

Because of our short season, starting watermelon seeds indoors three to four weeks before your last frost date is a smart move.
 
Use biodegradable pots since watermelon roots dislike being disturbed during transplanting.
 
Harden off your seedlings gradually before setting them into the garden when growing watermelon in Colorado.
 
 

Tips for Growing Watermelon in Colorado’s Climate

Once your transplants are in the ground, the real work of growing watermelon in Colorado begins.
 
Here’s how to give them the best chance in our unique climate.
 

1. Use Black Plastic Mulch

Black plastic mulch is a game-changer when growing watermelon in Colorado.
 
It warms the soil, conserves moisture, and suppresses weeds all at once.
 
Warmer soil means faster growth, which matters a lot in a short-season climate.
 

2. Protect Young Plants from Wind and Cold

Colorado’s spring weather can swing from 80°F to snow in a single week.
 
Use row covers, wall-of-water protectors, or cloches to shield young watermelon plants from cold nights and harsh winds.
 
Just remember to remove covers once flowers appear so pollinators can reach them.
 

3. Water Deeply but Not Too Often

Watermelons have deep roots, so watering deeply once or twice a week is usually better than shallow daily sprinkles.
 
Drip irrigation is ideal because it keeps foliage dry and reduces disease pressure.
 
When growing watermelon in Colorado, consistent moisture during flowering and fruit set is critical.
 

4. Fertilize Wisely

Watermelons are heavy feeders, but too much nitrogen gives you giant vines and no fruit.
 
Use a balanced fertilizer early on, then switch to something higher in phosphorus and potassium once flowers appear.
 
Compost-enriched soil also goes a long way when growing watermelon in Colorado.
 
 

Harvesting Watermelon in Colorado

Knowing when to harvest is the final piece of growing watermelon in Colorado successfully.
 
Here’s how to tell your melons are ready.
 

1. Check the Tendril Nearest the Fruit

When the curly tendril closest to the watermelon turns brown and dries up, that’s a strong sign it’s ripe.
 
This trick works well for almost every variety you might grow.
 

2. Look for a Creamy Yellow Spot

Flip the watermelon over and check the field spot, the area where it rested on the ground.
 
If it’s creamy yellow rather than white or green, your watermelon is likely ready.
 

3. Listen for the Thump

Give it a good knock.
 
A ripe watermelon sounds hollow and deep, while an unripe one sounds dull and flat.
 
Combine this with the tendril and field spot tests for the best results when growing watermelon in Colorado.
 
 

So, Can You Grow Watermelon in Colorado?

You can grow watermelon in Colorado as long as you choose short-season varieties, plant after the last frost, and use season extenders like black plastic mulch and row covers.
 
Our sunny summers are actually perfect for growing watermelon in Colorado once the soil warms up and the plants get established.
 
With a little patience and the right timing, you’ll be slicing into homegrown, sweet watermelon before the first frost hits.
 
Give it a try this season and see just how well growing watermelon in Colorado can work for you.