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How late can you plant watermelons?
You can plant watermelons as late as early to mid-summer, provided you have at least 70 to 90 days before the first frost.
But timing is everything.
If you plant watermelons too late, the fruit may not have enough time to ripen before cold weather arrives.
If you’re wondering how late you can plant watermelons and still get a harvest, the answer depends on your climate, your growing zone, and the variety you choose.
In this post, we’ll explore how late you can plant watermelons, the factors that affect late planting, and tips to make sure your crop matures in time.
Let’s dive in.
How Late Can You Plant Watermelons?
How late you can plant watermelons depends largely on your local climate and the length of your growing season.
Watermelons are warm-season crops that need plenty of heat and sunshine to thrive.
They typically require between 70 and 90 days from planting to harvest, depending on the variety.
That means if you plant watermelons too late in the season, they simply won’t have enough time to develop fully before the first frost kills them.
1. Check Your First Frost Date
The most important factor in determining how late you can plant watermelons is your first expected frost date.
Count backward 70 to 90 days from that date.
That gives you your absolute latest planting window.
For example, if your first frost typically arrives in mid-October, you shouldn’t plant watermelons any later than mid-July.
2. Consider Your USDA Growing Zone
Your USDA hardiness zone plays a huge role in how late you can plant watermelons.
Gardeners in zones 8 through 11 have longer growing seasons, so they can plant watermelons as late as July or even early August.
In cooler zones like 3 through 6, the window closes much earlier.
If you live in these regions, planting watermelons after June might be risky.
3. Choose Fast-Maturing Varieties
If you’re planting watermelons late in the season, choosing a fast-maturing variety can make all the difference.
Varieties like Sugar Baby, Golden Crown, and Blacktail Mountain mature in as little as 70 to 75 days.
These shorter-season watermelons give you a better chance of harvesting ripe fruit even when you plant late.
4. Use transplants instead of seeds
When you’re planting watermelons late, starting from transplants instead of seeds can save you weeks of growing time.
Transplants are already established and can start producing fruit much sooner than seeds planted directly in the ground.
You can plant watermelon transplants as late as early summer in most regions and still get a decent harvest.
Tips for Planting Watermelons Late in the Season
Planting watermelons late doesn’t mean you have to give up on a harvest.
With a few smart strategies, you can still enjoy juicy, homegrown watermelons even when you plant them later than usual.
1. Warm the Soil First
Watermelons need warm soil to germinate and grow.
If you’re planting watermelons late, make sure the soil temperature is at least 70°F.
You can use black plastic mulch to warm the soil and speed up growth.
2. Water Consistently
Watermelons are thirsty plants, especially during hot summer months.
When you plant watermelons late, consistent watering becomes even more critical.
Keep the soil evenly moist but not waterlogged, and avoid letting the plants dry out completely.
3. Fertilize Wisely
A balanced fertilizer helps watermelons grow strong and produce fruit faster.
Apply a phosphorus-rich fertilizer when you plant watermelons to encourage flowering and fruit development.
Avoid too much nitrogen, which promotes leafy growth instead of fruit.
4. Protect from Cold
If you’re planting watermelons late and cold weather is approaching, be ready to protect your plants.
Row covers or cloches can help extend the growing season by a few extra weeks.
This gives your watermelons more time to ripen before the frost hits.
Can You Plant Watermelons in July or August?
Yes, you can plant watermelons in July or August if you live in a warm climate with a long growing season.
In southern states like Texas, Florida, and Georgia, planting watermelons in July is totally doable.
But in cooler regions, planting watermelons that late is risky unless you use transplants and fast-maturing varieties.
The key is knowing your first frost date and counting backward.
If you have at least 70 days before frost, you can still plant watermelons and hope for a harvest.
So, How Late Can You Plant Watermelons?
You can plant watermelons as late as early to mid-summer, as long as you have 70 to 90 days before your first frost.
The exact timing depends on your climate, growing zone, and the variety you choose.
If you’re planting watermelons late, use transplants, pick fast-maturing varieties, and give them plenty of warmth, water, and care.
With the right approach, you can still enjoy a sweet, refreshing harvest even when you plant watermelons later than usual.
Happy gardening.