Growing Watermelons

Planting, Growing, and Harvesting Watermelons

By The Editors
Watermelons
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Everyone seems to love juicy watermelon in the summertime. Native to Africa, melons need warm temperatures (up to 80°F during the day) and a long growing season. Here’s how to plant and grow watermelons in your garden!

About Watermelons

Gardeners in colder climates can still have success in growing watermelon vines by starting seeds indoors and choosing short-season varieties. Days to maturity range from 70 to 90, depending on the variety.

Planting Dates for WATERMELONS

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Planting Calendar for all Plants

Planting

When to Plant Watermelons

  • In cool climates with short growing seasons, start seeds indoors 2 to 3 weeks before your last frost date. Plan to transplant seedlings into the garden about 2 weeks after that date.
  • In warmer climates with long growing seasons, sow seeds directly outdoors 1 to 2 weeks after your last frost date, as long as the soil temperature has warmed to at least 70°F (21°C). Warmer soil helps prevent poor germination.
  • Young watermelon plants can also be bought from nurseries. Plant these after there is no longer a chance of frost occurring. 
  • Note: Watermelon seedlings are very tender and should not be transplanted until all danger of frost has passed. Watch the local forecast and err on the side of caution!

Choosing and Preparing a Planting Site

  • Amend soil with aged manure, seaweed, and/or compost before planting. Watermelons are heavy feeders, meaning they need soil that is fertile and has a high nutrient level. Learn more about soil amendments and preparing soil for planting.
  • Watermelons do best in loamy, somewhat-sandy, well-drained soil.
  • Watermelons prefer a soil pH between 6.0 and 7.0 (“slightly acidic”).
  • Growing the vines in raised rows, known as hills, ensures good drainage and will hold the sun’s heat longer. Plan to space the plants about 2 feet apart in a 5-foot-wide hill. 
  • If you’re growing in rows, space 6 feet by 6 feet apart. 

Watermelon plant

How to Plant Watermelons

  • Sow seeds ½ to 1 inch deep outdoors or ¼ to ½ inch deep in seed-starting pots indoors.
    • Tip: To allow for greater root growth, use larger starting pots than you would for most seeds. Also consider using compostable pots that can be cut away or planted directly in the garden, as this will minimize the risk of damaging seedlings’ roots during transplanting.
  • If direct seeding outdoors, sow 4 to 6 seeds per hill, eventually thinning to 2 to 3 seedlings. 

Transplanting Seedlings

  • Handle seedlings with extreme care when you transplant. Their roots are very fragile, so try not to disturb the soil when removing them from pots.
  • After transplanting, cover the plants with row covers to keep pests at bay. Remember to remove the row covers when you see both male and female flowers on the vine, as pollinators will need to access the flowers.
  • Find even more tips for planting melons in your home garden.

Care

How to Grow Watermelons

    Watering

    • Watering is very important—from planting until fruit begins to form. While melon plants are growing, blooming, and setting fruit, they need 1 to 2 inches of water per week.
    • Keep soil moist, but not waterlogged. Water at the vine’s base in the morning, and try to avoid wetting the leaves and avoid overhead watering. Reduce watering once fruit are growing. Dry weather produces the sweetest melon.

    Fertilizing

    • If you choose to fertilize (and many do), make sure it delivers more nitrogen than phosphorus and potassium, as this will encourage leaf and vine growth. However, after flowering begins, use a fertilizer with less nitrogen to instead encourage flowers and fruit. We like to use a seaweed-based fertilizer.

    Flowering and Fruiting

    • Vines produce male and female flowers separately on the same plant. They often begin producing male flowers several weeks before the females appear. Do not be concerned if the male flowers fall off. The female flowers (which have a swollen bulb at the base) will stay on the vine and bear fruit.
    • Blossoms require pollination to set fruit, so be kind to the bees! Learn how to support pollinators in your garden.
    • As fruit is ripening, prevent rotting by gently lifting it and putting cardboard or straw between the fruit and the soil.

    Baby watermelon

    General Care Tips

    • Mulching with black plastic or straw around the plants will serve multiple purposes: it will warm the soil, hinder weed growth, and keep developing fruits off the soil.
    • Pruning generally isn’t necessary for watermelon plants, but vine productivity may be improved if you do not allow lateral (side) vines to grow and stick to the main vine. When the plant is young, just cut off the end buds as they form (before the side shoots become vines). You can also pinch off some blossoms to focus the energy on fewer melons (though it’s a challenge to kill off a potential fruit).

    Pests/Diseases

    Harvest/Storage

    Watermelons don’t continue ripening after they are picked, so harvest time is important. They generally ripen over a two-week period, so keep your eye on them.

    How to Tell If a Watermelon Is Ripe

    Dr. Bill Rhodes, professor of horticulture at Clemson University, offers the following advice on how to tell when watermelons are ripe:

    • Thump it. If the watermelon sounds hollow, it’s ripe.
    • Look at the color on the top. The watermelon is ripe when there is little contrast between the stripes.
    • Look at the color on the bottom. An immature watermelon will have a white bottom; a ripe melon will have a cream- or yellow-colored bottom.
    • Press on it. If the watermelon sounds like it gives a little, it’s ripe. (Note: Rhodes doesn’t like this method because it can ruin the quality of the fruit.)
    • Check the tendril. If it’s green, wait. If it’s half-dead, the watermelon is nearly ripe or ripe. If the tendril is fully dead, it’s ripe or overripe; it’s not going to get any riper, so you might as well pick!
    • Stems should be cut with a sharp knife close to the fruit.

    How to Store Watermelons

    • Watermelons can be stored uncut for about 10 days. If cut, they can last in the refrigerator for about 4 days. Wrap tightly in plastic.

    Recommended Varieties

    • ‘Sugar Baby’: 80 days to maturity. Produces 10-pound melons with bright red flesh. This variety of smaller fruit can be planted just 4 feet apart.
    • ‘Sweet Beauty’: 80 days to maturity. A 2004 All-America Selection. Bears 6-pound, oblong melons with red flesh.
    • ‘Golden Midget’: 70 days to maturity. Bears petite, yellow-skinned 3-pound melons with pink flesh. Good for Northern gardeners.

    Wit & Wisdom

    • What’s in a name? Watermelons are 90% water.
    • The pumpkin vine never bears watermelons.
    • August 3 is National Watermelon Day (U.S.)!

    Recipes

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    Reader Comments

    Leave a Comment

    Sugar baby watermelon sprouting yellow...

    Submitted by Madalena on April 28, 2016 - 12:38am

    Question: I planted some sugar baby watermelon in little starter cups. There are a few that sprouted and they are yellow. Are they too wet? I have others that have sprouted dark green, as they should be. Help please!
    Thank you in advance!!

    Watermelon planting

    Submitted by IJALANA E. F. on March 20, 2016 - 12:43pm

    Sir, I don't understand the planting space between column and rows. Can you explain?

    Novice watermelon gardener

    Submitted by Lolly on March 18, 2016 - 5:12pm

    I've started watermelon seeds in Jiffy peat pellets & at this time they're about 4". I've been preparing the soil for transplant. Here in So Tx the dirt is like clay. I've mixed in compost & potting soil to an area about 4'x6'. The seeds are Sugar baby. Do I need to transplant the seedlings asap, if so I hope my soil is satisfactory.

    My first time growing

    Submitted by Bob on March 16, 2016 - 10:50am

    My first time growing watermelon and I put the seeds in a 20 gal container next to my garden. I am expecting the vines to grow from the container into the garden. Right now my entire garden is covered in black paper to keep the weeds down. I was hoping that the watermelon will just grow over the paper. Does the paper need to be removed so the vines can grow in soil or is there enough soil in the container that the vines will produce. I live in Florida so it is already warm and I wonder if the dark paper will be too warm for the watermelons. Thanks in advance.
    Bob

    watermelon in container

    The Editors's picture

    Submitted by The Editors on March 16, 2016 - 3:40pm

    A 20-gal container is big; minimum 5 gallon is usually recommended. Does it have drainage holes? It will need a lot of water through the season, and as with any container, you want that water to be able to drain out.Water it daily when temps are below 80°F; twice when above.

    Black paper is generally used to warm the soil and, as you say, warm the soil and keep out weeds. But your plant’s primary soil—the soil it’s growing in—is in the container. Do you have a sandy, loose composted soil mix in the pot? Not dirt from the ground (such as under the black mulch), right? Watermelons like a loose mix to spread out in.

    Watermelon vines need something to cling to (when planted on the ground, this might be other plants or vines or even grass). You should expect to provide mesh or trellis or something to help guide your vines. We can’t be sure what they will do on the paper. The vines do not grow into the soil; the plants roots grow into the soil. Not sure if this answers your question.

    People often grow watermelons in containers because they lack the ground space, and with containers being relatively small, they choose varieties that produce small fruits. Consider the requirements of the seed variety you choose. (The size of your container makes us think that you’ve growing a large one.)

    let us know later in the year how all this works out. Good luck with it!

     

     

     

    The container I am using is

    Submitted by bob on March 16, 2016 - 4:54pm

    The container I am using is one that I had from a plant I purchase and planted in the yard so it has good drainage. The soil I put in the planter is just Miracle Gro potting soil. I have some rabbit fencing I could lay on the black paper for the vines. There are two plants in the planter. Do you think I will have to add fertilizer as the growing season progresses?

    fertilizer...

    The Editors's picture

    Submitted by The Editors on March 17, 2016 - 3:30pm

    Plan to fertilize with a general all-purpose produce when seedlings emerge, making sure to get it to the roots (use liquid, not solid fertilizer). Liquid seaweed fertilizer can be applied after leaves appear and once flowers emerge. Watermelons also benefit from nitrogen when vines begin to take off and when fruit appears. Use a 33-0-0, well diluted. Stop nitrogen applications when fruit has set and replace it with something high in phosphorus and potassium. Read more about these essential beneficial ingredients—and more—here: http://www.almanac.com/content/preparing-soil-planting

     

    watermelon farming

    Submitted by Ambrose Alufah on February 28, 2016 - 2:55pm

    Your write up is so educating, thank you. I'm interested in watermelon farming, how can I learn all I need to know about this? E.g . Best variaties of water melon, Favourable environment, Maturity period, Best farming seasons, Best fertilizers to be used, Planting methods e.t.c.
    I live in Nigeria. I'll really appreciate your help in this regard. Thanks.
    Ambrose Alufah

    Water mellon farming

    Submitted by Ekeruche Ugochukwu on March 7, 2016 - 11:55am

    I am watermellon farmer i live in warri delta state nigeria. No variaty is bad it depends on ur kind of soil dare4 test

    I would like to contact Ugochukwu

    Submitted by Tega on December 13, 2017 - 12:09pm

    Good day Mr.Ugochukwu Ekeruche. Can I contact you? I'm just starting the watermelon farming near Warri.
    You can contact me via 08059067489 or via WhatsApp on 08055330844.

    Watermelon

    Submitted by Leah Kyonka on March 8, 2016 - 8:53am

    Go to Baker Creek Heirloom Seeds' website bakercreekseeds.com and they have a huge variety and all the information you could use. Also I'd say don't transplant your watermelons, squash and melons of all kinds like to stay put.

    Growing Watermelons

    The Editors's picture

    Submitted by The Editors on March 8, 2016 - 11:12am

    Many thanks for your kind words.  Unfortunately, we can only give gardening advice for North America. The Old Farmer’s Almanac is only published in the U.S. and Canada, hence our expertise. However, there is much information above about watermelon planting and growing which should apply to you, regardless of region. All the best.

    Inquiries

    Submitted by Nosa uyi on February 28, 2016 - 4:21am

    I am from the southern part of Nigerian, please I am interested in this watermelon farming and I need advice and guidance as to the following
    1. Best variaties of water melon
    2. Favourable environment
    3. Maturity period
    4. Best farming seasons
    5. Best fertilizers to be used
    6. Planting methods
    7. Any other things I need to know
    Thanks ...
    Nosa Uyi
    Dangoteofbenin@gmail.com

    watermelon

    Submitted by samuel okere on February 3, 2016 - 6:53pm

    I am interested in growing watermelon, cucumber, okra, tomato and carrot so I am looking for any practical guide on organic farming resource with direct link to were the seeds can be sourced.
    Thanks

    Is there anything wrong if i

    Submitted by Bamidele Fasoranti on November 7, 2015 - 5:45am

    Is there anything wrong if i plant water melon in November

    Watermelon in November

    The Editors's picture

    Submitted by The Editors on November 10, 2015 - 10:33am

    There is nothing “wrong” with planting watermelon in November if you can be certain that summer conditions will prevail for the next 100-or-so days (the number of days to maturity will appear on the seed packet). If you are entering the winter season, now is not the time to plant watermelon outdoors.

    watermelon rinds

    Submitted by Greg on October 2, 2015 - 7:01pm

    I grew seeded watermelons. Had about 6-7 large melons per three plant hills. They weighed 15 to 20 pounds and were juice and very sweet. no complaints. But the rinds were at least a inch and half thick. Seemed excessive. Is there something that may cause rinds to be thicker. Just curious. Thanks

    Watermelons

    Submitted by Greg kaser on October 1, 2015 - 9:34am

    I grew seeded watermelons this summer. Can't remember the variety but had four to five 15 pound watermelons per hill of three plants. Turned out they were very sweet and juicy when we picked them. My concern was that the rind was at least one and a half inches thick.
    Doesn't seem normal. Is there a reason for exceptionally thick rinds? We live in The Dalles, Oregon. Thanks.

    Watermelon

    Submitted by Rick on September 22, 2015 - 5:46pm

    I planted Sugar Baby Watermelon. It's growing very good. They are solid green but I'm not sure when to pick it. They do sound hollow now. Please advise

    Hi - what is the reason that

    Submitted by Kathyt07002 on September 9, 2015 - 11:56am

    Hi - what is the reason that my watermelon is white inside? It is not sweet and the seeds are white too. Not sure what type I got, I planted a seed from a store bought watermelon. The watermelons are oblong with stripes. I cut one off because it was getting rotten at the tip. It was about 3 lbs. I would appreciate your response. Thank you.

    The watermeons at the grocery

    The Editors's picture

    Submitted by The Editors on September 10, 2015 - 3:37pm

    The watermeons at the grocery store are most likely hybrids, which are a cross between two different varieties. When you plant a seed from a (non-sterile) hybrid, the resulting fruit may not come out exactly like the original fruit (may not "come true"). They might be like one parent plant, or something totally different. There are white-fleshed watermelons; perhaps a white-fleshed watermelon was an ancestor to the watermelon that you saved the seed from?

    My watermelons are as big as

    Submitted by Rebecca Meaney on September 20, 2015 - 11:51pm

    My watermelons are as big as a Granny Smith Apple
    How much longer till mature?

    Do you know what variety it

    The Editors's picture

    Submitted by The Editors on September 23, 2015 - 8:23am

    Do you know what variety it is? Do you still have the seed packet? They have a wealth of information on them like how many days it takes for the fruit to mature. I'd say that unless you have grown a watermelon that is supposed to be that small, you need to wait a little longer before harvesting. See the tests for maturity listed in the watermelon article above to know when it is time to pick it.

    Rotten tip watermelons

    Submitted by Dave on March 23, 2016 - 9:42pm

    This does happen with watermelons. For whatever reason some rot like this. It would have never reached maturity. I usually cut those kind off. Wait till the melon is yellowish on the bottom side then it is ripe.

    I planted some jublie

    Submitted by brooks559 on September 4, 2015 - 1:31am

    I planted some jublie watermelons about 2 year's ago and they would sound ripe when thumped cut it open and still be green. Waited till the vine started to discolor same thing still green even went as far as the vein being rotting off and still green. A old timer told me I messed up when I limed my garden area I don't know if he was correct or not but most old farmers had been there done that and hardly ever wrong. I just wanted to get everyones input. I ended up plowing them up and didn't mess with it the following year and had some volunteers start growing and ended up geting a few ripe one's.

    Your old farmer friend might

    The Editors's picture

    Submitted by The Editors on September 6, 2015 - 9:08am

    Your old farmer friend might be right! Watermelons like soil a little on the acidic side, a pH of 6-6.8 at the highest down to 5 at the lowest. Test your soil before you add any more amendments. The leaves produce sugars that help your watermelons to ripen. If they are dying off prematurely due to disease or insects the fruit doesn't stand of chance of ripening. Nothing is more disappointing than cutting into a melon you have been growing for months only to find that it is not ripe! Some tests, other than the thump test (which I have never perfected) are:
    The tendril closest to the fruit will turn brown.
    The fruit will twist off easily from the stem.
    The white spot on the bottom of the fruit will turn yellow.
    The rind of the melon will be dull green.
    The vine nearest the end of the fruit will be cracked and brown.
    The fruit should smell sweet when sniffed.
    They should have a slight give when squeezed.

    Hi, we planted watermelons

    Submitted by lildeb18 on August 14, 2015 - 2:13pm

    Hi, we planted watermelons this year, and do have watermelons growing pretty well. the problem is I keep finding some of my melons with eaten spots out of them, thinking a rabbit! Any ideas to keep him from eating them without hurting the rabbit? Is is possible if the eaten part isn't all the way thru the fruit,am I able to save any ot those? Thank you

    You can fence off the melon

    The Editors's picture

    Submitted by The Editors on August 16, 2015 - 9:49am

    You can fence off the melon patch with chicken wire. Just be sure to bury it at least 6 inches deep around the edges to discourage them from digging underneath. Deterrants such as coyote urine or bobcat urine might scare them off. Blood meal can also be used to repel them. One industrious gardener builds hardware cloth cages that he places around each melon to protect it as it grows.
    If the gnawing damage doesn't extend into the flesh, it might seal over naturally and continue to grow with no problem otherwise the hole will provide an entry place for all sorts of rot and disease.

    Go to a barber shop or your

    Submitted by Kim knight on August 16, 2015 - 10:31pm

    Go to a barber shop or your hairdresser and get some hair and put around yor garden it smells of human will deter the animals.

    You can take a rag or towel

    Submitted by brooks559 on September 4, 2015 - 1:41am

    You can take a rag or towel and put ammonia on it or bar of soap and cut up in the garden area in multiple areas I have heard of hair working also heard of people peeing aroind the garden. Probley best thing is a couple a fake owels or something motion sensored. Fence works for smaller animals . But wont stop a deer they say to keep a deer out is to get a mesh like fenceing and fix it in a way laying flat about 1 to2 feet off the ground cause the deer has good height perception but have depth or width perception which ever way you look at in. | ----

    Pages

    Growing Watermelons

    Botanical Name Citrullus lanatus
    Plant Type Fruit
    Sun Exposure Full Sun
    Soil Type Sandy
    Soil pH Slightly Acidic to Neutral
    Bloom Time Summer
    Flower Color Yellow
    Hardiness Zones 3, 4, 5, 6, 7, 8, 9, 10, 11
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