How to Grow Watermelon for the Best Flavor

Watermelon developing1
How to grow Watermelon developing
How to Grow Watermelon: Watermelon demands warm temperatures—both soil and air.

Luscious, liquid sweetness: since watermelon is nearly always eaten on its own either sliced or quartered, growing it juicy and sweet is always the objective.

To grow sweet and tasty watermelon, follow these steps:

Temperature. Watermelon demands warm temperatures—both soil and air. Transplant or direct seed watermelon only when the average soil and daytime air temperatures are at least 70°F (21°C). Do not grow watermelon unprotected where nighttime air temperatures fall below 60°F (16°C). If the air temperature dips, protect watermelons with floating row covers.

More growing tips at How to Grow Watermelon.

Soil. Grow watermelon in rich, well-drained soil. Planting watermelon on hills or mounds ensures that roots stay warm and that the soil is well drained. Amend the planting area with compost and well-rotted manure. Where you plan to sow seed or set transplants, dig a hole 1 foot (30 cm) deep and 1 foot wide; fill the hole with rich aged compost and manure mixed with several handfuls of sand—the growing spot will be both moisture retentive and well-draining. Add a handful each of rock phosphate (rich in phosphorus), earthworm castings (all-round nutrient rich), and Epsom salts (rich in magnesium). Use the soil removed from the hole to build a mound on top and rake it flat. Sow seed or set a transplant there. Watermelon roots commonly grow 8 to 10 or more inches deep; the hole and mound become a reservoir of moisture and nutrients. More tips: Watermelon Seed Starting Tips.

Care. Space watermelons 6 to 12 feet (1.8-3.6 m) apart; don’t let plants compete for soil moisture or nutrients. (Keep weeds down until vines spread and shade the soil.) If watermelons are stressed for water or nutrients when they start to set fruit, they will be small and less flavorful. Feed watermelons with a dilute solution of fish emulsion fertilizer—1 tablespoon per gallon of water—weekly from the time the plant is a seedling until the first female flower appears. (Mark the calendar on the day the female flowers fully open—the fruit will be ready for harvest 35 days later.)

Water. Give watermelons even moisture from planting through fruit set. During the first 3 to 4 weeks of growth a watermelon develops its root system. The root system supplies the growing plant with both moisture and nutrients. An extensive and strong root system allows the watermelon to take up nearly 95 percent of its weight in water and develop its large cells which are easily seen with the naked eye—these large, water-filled cells give watermelon its crunchy, crisp, yet tender consistency. Never allow a developing watermelon to dry out completely or it may split. Water whenever the top 3 to 4 inches (8-10 cm) of soil become dry; simply stick your finger into the soil to test the soil moisture. Apply a heavy mulch to keep the soil moist after the sun begins to warm the garden in summer.

When to water. Do not overwater a watermelon once it has begun to set fruit or its developing natural sugars will be diluted. The leaves of a watermelon commonly wilt in the hot afternoon sun. Water immediately if the watermelon’s leaves wilt before noon or if they appeared stressed by heat or drought. Never allow the vine itself to become dry. A soaker hose or drip irrigation is the best way to deliver water to watermelon roots; overhead watering may encourage the development of fungal diseases which commonly attack leaves.

No water. Stop watering a watermelon about 2 weeks before the fruits are ready to harvest. Holding back water at this point will concentrate the plant’s sugars and the fruits will become sweeter tasting. More tips:

Harvest. A watermelon is ready for harvest when the curly tendrils on the stem nearest the fruit dry up and turn brown and the spot on bottom of the fruit turns from white or green to yellow or creamy yellow and the top of the fruit turns a dull color. Mark Twain observed that a green melon says “pink” or “pank” when thumped with the knuckles. A ripe watermelon says “punk.” “Punk” is best described as a solid dull sound. More tips: How to Harvest and Store Watermelon.

Two flavorful watermelon favorites:

  • Sugar Baby: small, round red-fleshed fruit, 8 to 10 pounds (3.6-4.5 kg); 80 days to harvest, open-pollinated.
  • Yellow Doll: small, round, crisp, yellow-fleshed fruit, 5 to 7 pounds (2.2-3 kg), semi-compact vines; 68 days to harvest, hybrid.

Watermelon varieties to grow: Watermelons: Top 10 Varieties.

Written by Stephen Albert

Stephen Albert is a horticulturist, master gardener, and certified nurseryman who has taught at the University of California for more than 25 years. He holds graduate degrees from the University of California and the University of Iowa. His books include Vegetable Garden Grower’s Guide, Vegetable Garden Almanac & Planner, Tomato Grower’s Answer Book, and Kitchen Garden Grower’s Guide. His Vegetable Garden Grower’s Masterclass is available online. has more than 10 million visitors each year.


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  1. Thank you so very much for this article it explained a lot to me I did not know my first time for planning watermelon and cantaloupe probably won’t get much this year if I get anything but it gave me a lot of knowledge for next year

    • If your watermelon has formed fruit, place a tile or a sheet of aluminium foil under each fruit; this will aid ripening. Feed the plants compost tea or a dilute fish emulsion mixture every 10 days as well.

  2. I have recently planted my first crop of watermelons, and found the above advice extremely helpful.
    Lots of info and some great tips. 🙂
    Thanks very much. Greatly appreciated

      • Thank you for your watermelon tips. My first time to try in California. Knowing nothing about planting. I planted from a small plant I purchased at HomeDepot

    • The potato tuberworm is the larvae of the potato tuber moth (Phthorimaea operculella). The moth lays its eggs in garden plant debris, the soil near potatoes, and in stored potato tubers. A female moth can lay 60 to 200 eggs at one time. The eggs are smooth and white. The larvae can overwinter in the garden or in stored potatoes. The larvae (worms) are white or yellow with brown heads. The worms feed on potato leaves, stems, and mostly tubers. They bore tunnels in the tubers and leave behind black excrement; the tubers become spoiled and unfit for human consumption. Tubers in the ground or in storage can be attacked. To control potato tuberworms do the following: (1) eliminate weeds from the garden where moths or eggs can hide or overwinter; (2) plant seed potatoes at least 2 inches deep and when hilling potatoes hill up at least 2 inches of soil; this can help put potatoes out of reach of worms; (3) plant only healthy, uninfected seed potatoes; (4) harvest potatoes as soon as they are mature; do not let them linger in the garden; also, do not let harvested potatoes sit exposed overnight in the garden; (5) keep the soil moist, but not wet; avoid dry soil; tubermoths lay eggs in dry cracks in the soil; (6) plant tuberworm resistant cultivars; (7) pesticides containing Bacillus thuringiensis (Bt) may help control tuberworms and moths; check with the nearby Cooperative Extension for other controls that may work in your area; (8) store potatoes at temperatures lower than 52F; (9) place pheromone traps in storage areas to catch the moths.

  3. I planted a sugar baby melon. I did not realize to not water from the top. That explains why the leaves are a bit unhealthy looking. Next year I will prep soil more thoroughly. This year I will follow the advice I learned here and hope for the best. Thank you and may sweet watermelon juices dribble down your chins!!!

    • Thanks for reading Harvest to Table. You likely still have plenty of time to get a couple more watermelon seedlings growing this season. Happy Gardening!

    • Watermelons are more than 90 percent water. You can grow watermelons in a dry location, but you must provide them with consistent moisture for the melons to mature. Watermelons can not be grown without sufficient rainfall or irrigation.

      • Hi Steve, I have Sugar Baby (I think,maybe crimson) and I’ve got 28 various sized watermelons. Today I opened one of the big ones and it was red all the way through but it tastes watery. Then I read, when your close to pulling your fruit to not water them for the last two weeks. I’m in AZ, so does that still hold water? I would think it will totally kill all the vines. Although I haven’t watered for four days at this point we had a massive rain storm came through. Please help. Thank you

        • Reducing or withholding water to watermelons ahead of harvest will concentrate the sugars and flavor. You can experiment with the number of days ahead of harvest; try a week or 10 days rather than two weeks if you are concerned the plant will not survive. If you watered up until harvest and the taste was watery, you now have a baseline. Stop watering one week ahead of harvest and you can judge the flavor.

  4. Hello. I have fish fertilizer (5-1-1) Is it ok to use this as well as another liquid fertilizer with higher phosphate per week or should I rotate the weeks, fish fertilizer one week and another fertilizer the next? I need all the tips I can get for how to do this. Thanks so much. By the way, some of my seedlings just came up so I want to be sure I do this right to ensure a great harvest this year.

    • The best course would be to use just one product and follow the directions on the package. Fish fertilizer is a good choice to help establish you young plants or for leafy crops. Once a watermelon plant is established, use a low nitrogen higher phosphorus fertilizer.

      • I really appreciate your help, Steve. Sorry that I’ve been asking so many questions but the failure of my crops was a huge disappointment for me. I’m still learning and can use all the help possible. I’m hoping that I get it right this go around. Thanks so much again. Blessings!

  5. I grew ice box watermelons in containers last year, in northeast PA. I put them in way too late (third week of June) and they didn’t do too well. This year I put them in on May 23, didn’t bother to cover then at night (we had several nights below 60) and i have them under the same drip fertigation system as my tomatoes. They look amazing so far with plenty of baby melons. The even watering and steady application of fertilizer seem to be right up their alley. I’ll remove the drippers when the time comes. Thanks for that tip! Crossing my fingers for juicy ripe melons this year.

    • Once your vines have set the number of fruit you want, usually 2 per vine is enough; then you can nip off new flowers and pinch or trim away the growth tips of the vines beyond the melons. You do want leaves to help nutrient conversion for fruit growth; so your pruning should not be severe.

  6. Your info is great! I’ve never grown watermelons before, I used a 6-4-4 water soluble fert. to start them followed with a 2-8-4 fert. after flowers appeared, should I continue with this ratio until harvest or should I also use a worm tea ratio 0.1- 0.1-0.1? My melons are about thumb-size

    • Continue with the 2-8-4 until the fruit is the size of a cantaloupe; then use the worm tea. You can stop feeding a month or so before harvest. Set the young melons on a tile or board or piece of plastic so they get reflected solar heat. Keep the soil just moist.

  7. How much Epsom salt do I use and do you mix it with water or just spread it over the top of the soil when your watermelon plants are flowering?

  8. I am saving this article for next year, to late to save mine this year. For 2 years I have tried to grow watermelon and no luck, this year I planted them in their own individual planters and used miracle grow. I got really good seedlings but only 2 melons that are very small ( they are not sugar babies) they are about the size of my 2 fist together and an odd shape. I was just to the point of not planting any next year then I saw your article and well, I am going to do it again and hopefully get a few melons. I had no idea melons were tricky to grow lol…
    I have plenty of manure and instead of letting the BF give it away, I am going to keep some to use ( we have steers so he can still give it away just not all now )I have heard that sand is good to grow melons in, is this correct? If so I will buy some next growing season and mix it well with old manure and the other suggestions in the article. Can’t wait to do this next year, thanks for the tips.

    • A suggestion: apply the manure to the garden in late autumn so that winter rains or snow carry the nutrients deep into the soil; as well, add aged compost. Manure and aged compost should loosen the soil since both contain lots of organic matter; you can add some sand, but you may not need it with plenty of aged compost added. If you use a commercial fertilizer make sure that the nitrogen is not greater than 5 for watermelons, 5-10-10 is best. Keep the soil evenly moist throughout the growing time; watering in fits and starts can cause melons to take on odd shapes.

      • Thank you for your help.

        I did as you said and have manure and compost in the soil.

        I will hold off on sand and may hold off on any store bought fertilizer.

        I have some tips now so I am excited to give it another try.

        Thanks again

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