How to Grow Juicy Watermelons in Containers Even If You Don’t Have a Yard

Growing watermelons in containers is a great way to enjoy this sweet summertime treat even if you only have a small space like a patio, balcony or rooftop. With the right containers, soil, seeds and care, you can harvest ripe watermelons from pots right outside your backdoor!

Choosing the Right Container

The most important thing when growing watermelons in pots is choosing the right container Watermelon vines can spread over 15 feet, so you need a container that’s big enough to accommodate the spreading vines

• For each watermelon plant, use at least a 5-gallon or larger container. The bigger the better!
• Make sure the container has drainage holes in the bottom to prevent waterlogged soil.
• Use containers that are at least 12-24 inches wide. Round, square or rectangle shaped pots all work.
• Plastic, ceramic, wood or fabric pots all work well. Make sure they are sturdy enough to hold the soil, vine and fruits.

Many people use half whiskey barrels or fabric smart pots for growing watermelon in containers. You can also make your own watermelon planter by drilling drainage holes in a clean trash can or plastic storage bin.

The Right Soil is Key

Watermelons need loose well-draining soil to grow properly in pots. Heavy garden soil that compacts easily is not a good choice for container watermelons.

The best potting mix for watermelons includes:

• Potting soil – Use a high quality potting mix as the base. Do not use garden soil!
• Compost – Add 20-30% compost to improve drainage and nutrients
• Perlite or vermiculite – Mix in approx. 10% for aeration and moisture retention
• You can also find commercial potting mixes for vegetables that have the right blend.

Before planting, fill your container about 1⁄2 to 1 inch from the top with moistened soil mix to leave room for watering.

Choosing Compact Watermelon Varieties

While you can technically grow any watermelon variety in a pot, your best bet is to choose a compact, bush-type variety that’s suited for container growing. These smaller varieties will be easier to manage and produce fruit in pots:

• Sugar Baby – The classic compact variety, produces 8-10 lb melons on 5 foot vines. Round shape.
• Orangeglo – 10 lb orange-fleshed melons. Semi-dwarf vines.
• Jade Star – Oblong 8 lb melons on vines 5-7 feet long.
• Crimson Sweet – 10-15 lb classic oval melons on 6 foot vines.
• Bush Jubilee – 10 lb striped melons on vines just 3-4 feet long.

You can grow standard sized watermelon varieties like Crimson Sweet in large containers, but the fruits and vines will be much bigger. Stick to true compact, bush or dwarf varieties if space is limited.

Start Seeds Indoors for a Head Start

Watermelons grow best when started indoors and transplanted outside after the weather warms up. Here’s how:

• Start seeds indoors 4-6 weeks before your last spring frost date.
• Fill seed starting pots or trays with potting mix. Leave 1 inch of space at the top.
• Plant seeds 1 inch deep in the soil. Water lightly.
• Cover with plastic wrap/dome to retain moisture as seeds germinate.
• Move the seedlings to full sun 1-2 weeks after sprouting.
• Harden off plants for 7-10 days before transplanting them into containers outdoors after all danger of frost has passed.

Direct sowing watermelon seeds into containers outdoors is also an option. Just be sure to wait 2-4 weeks after your last expected frost date. Soaking the seeds in water for a few hours before planting can help improve germination rates.

Provide Sturdy Support for Vines

As watermelon vines grow they can get heavy and unruly. Giving them proper support is key for container grown watermelons:

• Use a trellis, pergola or fence to guide vines upward and prevent them from sprawling on the ground.
• Train vines to grow up a teepee made from 5-6 tall bamboo stakes and plant ties.
• Attach vine tendrils to netting stretched between posts or rails to support their weight.
• Use soft fabric slings under developing fruits to prevent breakage.

Properly supporting container watermelons will lead to healthier vines and larger fruits.

Water and Fertilize Often

Water and fertilizer needs are higher for watermelons grown in pots. Check soil moisture daily and water pots when the top inch becomes dry. Increase watering during heat waves.

• During the growing season, apply a water soluble fertilizer like fish emulsion or liquid kelp weekly according to label rates.
• You can also use slow release granular fertilizer at planting time and again 6 weeks later if needed.
• Side dress pots with extra compost or manure mid-season for an organic nutrient boost.

Consistent moisture and nutrients are very important when growing watermelons in containers. Don’t let pots completely dry out.

Pollinate by Hand for Best Fruit Set

Bees play an important role in pollinating watermelon flowers. Container grown watermelons may need a little help producing fruits if pollinators are scarce:

• Use a small brush to transfer pollen from male to female flowers. Female blooms have a tiny watermelon fruit behind the flower.
• Or try vibrating flowers gently to release pollen which may be spread by wind.
• Pollinating by hand ensures adequate fruit set if bees aren’t readily available.

Harvest Ripe, Juicy Watermelons

It takes about 70-90 days from seeding or transplanting for watermelons to be ready to pick. Here’s how to know when container grown watermelons are ripe:

• The curly tendril vine closest to the fruit will turn brown and dry up.
• The watermelon rind will take on a dull, matte look instead of shiny green.
• Press your thumb into the rind near the underside and it should dent slightly.
• The underside of the melon (where it rested on soil) will turn from white to yellow.
• Use a knife to slice a small plug in the rind to check interior color – deep red = ripe!

Twist melons off the vine or use pruners to snip the stem near the fruit. Enjoy your homegrown watermelons on the spot or store them for 1-2 weeks in the fridge.

Growing sweet, tasty watermelons in pots on your patio or balcony is completely doable with the right setup and care. Follow this container growing guide and you’ll be harvesting vine-ripened melons all summer long!