How to Grow Watermelons in a Raised Bed Garden Donna Larson, July 21, 2024July 21, 2024 Folks don’t always realize that they can grow vining plants such as squash and melons in unconventional methods. They’ll read that they need lots of room to run and sprawl along the ground, but we’re going to share how to grow watermelons in a raised bed. The Advantages of Why You’d Want to Know How to Grow Watermelon in a Raised Bed Most backyard gardens are small gardens, and they don’t have extra room to allow plants to spread out. The limited space given to the gardener is used up for growing a broad variety of fruits and vegetables. They don’t want to leave space for a “extra” foliage. While they do need a lot of space to grow, melons and other vining plants can certainly be grown in raised beds. Just think vertically. Given the right conditions and opportunity, your watermelons will happily grow upwards instead of outwards. How to Grow Watermelons in a Raised Bed You need to provide the right growing conditions for your watermelon plants whether their growing space is in the ground or in raised beds. Consider these important aspects to growing healthy watermelon plants. Right Variety Quality Seed Healthy Soil Regular Fertilizing Watering Sunlight Pollination Trellising Support Harvest Time The Right Varieties of Watermelon for Trellising The right watermelons that grow smaller fruits are going to be your best bet for trellising because large melons are difficult to keep in tact as their weight pulls on their vines. A secondary benefit of growing smaller watermelon varieties is that they often finish to ripe faster than larger varieties. If you have a shorter growing season, you may enjoy greater success with these melons. Sugar babies, Icebox, and Sun, Moon, and Stars all grow to about 10 pounds and mature in about 75 days. If you’re in the south with heavy humidity, look for disease-resistant varieties. Fusarium wilt and gummy stem blight are common fungal diseases the home gardener may face when attempting to grow watermelons. Florida Giant and Black Diamond are two hybrid varieties that you may like in muggy growing conditions. Check recommendations on the seed packet for disease resistance. I absolutely love the idea of “landracing” watermelons to breed the best variety for your microclimate. Our friend, David, has done this with excellent results after just a few short years. How to Grow Watermelons in a Raised Bed From Seed You can easily grow watermelons by direct sowing seeds into your raised beds; however, you may have even better success by starting your seeds in trays to transplant. Melons, cucumbers, and squash don’t like their roots to be disturbed too much. Using larger pots in trays can help you avoid this problem. By starting seeds indoors in trays, you can bring strong plants into your raised bed garden. This can also help you get a jump start on the growing season before your soil temperature is warm enough to support your young plants. Simply start your seeds in a quality seed mix, keep your pots moist (but not wet) during germination, and give them plenty of light and warmth to grow indoors. That’s the shortened version, but we have an entire detailed guide on The Best Tips for Starting Seeds Indoors With Grow Lights. Once your little plants have their first set of true leaves, harden them off, and transplant them into your garden. Soil Requirements for Growing Watermelons in a Raised Beds Melons, whether you’re planting baby plants or watermelon seeds, need well-drained soil with lots of organic matter. They like a slightly acidic soil between 6 and 7 on the pH scale. Think compost. My best watermelon vines have grown effortlessly out of the compost pile (pumpkins too but that’s another discussion). Top your garden bed with 4 to 6 inches of finished compost. Transplant your watermelons every 18 to 24 inches apart inside of your raised beds. Water them well, and watch them take off. As they grow a curly tendril or two, train them up the trellis that you’ve chosen. A Sturdy Trellis Make sure that you choose a trellis that can hold the weight of several long vines and fruits. A heavy duty trellis will be necessary. The worst is growing beautiful vines with producing fruits only to have a flimsy trellis collapse with your ripe fruit crashing to the ground. Maintaining Watermelon Plants During the Growing Season Once planted, your watermelons will grow long vines up their trellises, and you’ll have some maintenance work to do. 1. Pruning Pruning is an optional but suggested practice for larger fruits and good air circulation. Start by finding the main vine that grows from the ground. From there, you’ll find side chutes of vines that sprawl out from the plant. You may trim those off completely if you’d like. Alternatively, you can leave the secondary vines of your watermelons plants, allowing them to ramble on and give you more, smaller melons. You will need to be cautious of poor air flow bringing on fungal diseases. 2. Fertilizing Watermelons are known to be heavy feeders, needing an abundance of nutrients. If you’re planting in straight compost piles, you may find that you need very little help feeding your watermelon plants. If you notice yellowing of leaves, feeding them some added nitrogen is needed. 3. Watering All melons, but especially watermelons, need even watering. Too much water at one time, especially after a dry spell, will cause your fruit to split. Not enough water will cause stunted growth and drying vines. A good rule of thumb is to supply your plants with an inch of water per day, right at the root systems. Heavy mulching your plants is a good idea to keep them happy in moist, warm soil. A thick layer of wood chip mulch will help keep the balance of even watering for your watermelon plants. 4. Plenty of Sunshine Watermelons like warm weather and full sun. Here in Florida, watermelon farmers grow acres of watermelons with no shade. Those plants grow in 15 hours of sunlight per day. They use no shade cloth and there are no trees in the fields. Don’t try to shield your watermelons from the sun. Instead, make sure your plants have plenty of water. 5. Pollination Watermelons require insects to come by and pollinate their flowers in order to produce fruit. Attracting plenty of beneficial insects with other flowering crops nearby is highly recommended. Each watermelon vine will produce separate male and female flowers. They need honey bees and other nectar-loving insects to come by, spreading pollen from the male flower to the sticky stigma of the female flower. Only then, can the plant grow fruit. Be sure to limit your insecticide use, even if organic, so that your garden is a friendly place to receive pollinators. If attempting to use row covers to keep pests out, know that you’re also keeping beneficial pollinators out. You can hand pollinate with a paint brush or Q-tip under such circumstances. 6. Offering an Additional Support Structure for Large Fruits Watermelon vines are strong, but sometimes, even the smaller fruits can grow unexpectedly large. This puts great strain on your vines as the fruit hangs from your trellis. Consider offering additional support of the larger fruits, to ease the tension on your watermelon vines. Slings made from mesh netting, toole, or old t-shirts provide excellent support to your heavier fruiting plants. Many gardeners like to use hosiery because the elasticity creates expansion as the fruit grows. Slip your baby fruits inside and tie them up to the trellis. Harvesting Fruits To determine ripeness, thump the melon. If it sounds like an echo, it’s ripe. If thumping is too subjective for you to decide to pick or not, look at the tendril that is nearest the melon. When that tendril dries to shrivel up, your watermelon is ready to pick. Moreover, the skin of a ripened watermelon will be dull, not shiny or waxy looking. If you happen to have one grow on the soil of your raised bed, the belly (the spot that touches the soil), will turn yellow as the fruit ripens. To harvest your watermelons, take a pair of sharp shears or garden scissors. Do not try to break the stems, as you’ll end up fraying the vines. This invites disease and signals nearby pests that the plant is stressed. Lastly, leave an inch of stem on the melon when you cut it. Summary of How to Grow Watermelons in a Raised Bed We hope that this guide on how to grow watermelons in a raised bed garden gives you some direction and encouragement if you’re gardening in a limited space. Vertical growing can solve the problem of where to put vining plants when using raised bed gardens. There’s nothing sweeter than tackling a garden problem that gives you your own watermelon on a hot summer day. Let us know what works for you. Happy Growing! Donna @ Hazel Belle Farm Donna and her family have been homesteading for most of their 20+ years together in some shape or fashion. She currently lives on their 20 acre farm where they grow as much food as possible. What started as a just a few laying hens, has grown into large gardens, pastured poultry, pork, and lamb. They are continuously evolving their small farm to not suit their family’s needs, but also providing to their local community. Donna’s favorite part of the family farm is her self-built micro-dairy, where she gets to love on dairy cows while serving her local community. Milking, cheesemaking, and processing dairy have become the soul of their homestead and the center of their farm. Gardening Homesteading