Summer’s classically large watermelons have long, sprawling vines that take up a lot of valuable growing space as we await their long-maturing fruits. Growing them is a labor of love, with readiness in about 80 to 100 days. And there’s nothing like slicing into giant, fresh-picked melon at peak ripeness, except for a smaller, just-as-sweet version.

To conserve some precious real estate, growing watermelons in pots and containers makes them accessible across garden scales. More compact vining or bush types grow in smaller spaces and require less room to run. With a trellis or support, their upright development hosts a number of benefits, including untapped dimension, visual interest, and good airflow to ward off common diseases.

Provide The Best Site

Choose a place with ample sunlight and appropriate temperature.

Watermelons, Citrullus lanatus, soak up the sun and heat on summer days as the sugary fruits develop and fill with sweet juice. They do best in full sun, with six or more hours of sunlight daily. They need warmth to germinate, and quickly take off as temperatures reach the 70s and above (21°C+).

Watermelons join squash and cucumbers as members of the Cucurbitaceae family. They’re susceptible to the same pests and diseases, so it’s best to separate the group when practical. Opt for pollinator-attracting and companion plants to promote health and pollination.

Containers dry out more quickly than in-ground plantings, so easy access to water is essential. Plan to check the pots and water regularly. To save effort and conserve water, a simple drip irrigation system helps deliver water directly to the root zone. Set the system on a timer to aim for consistent moisture (handy when you go on vacation, too).

Make sure the pot has sufficient drainage holes to avoid saturated soils. Opt for a high-quality potting mix to establish a healthy foundation. Organic formulas tailored to containers are light and well-draining. They’re also sterile and contain nutrients to foster growth. Top dress with a mulch layer to boost moisture retention and regulate soil temperatures. Keep the mulch off the stems to prevent disease and pest issues.

Direct Sow or Transplant

Sowing seeds directly can prevent root disturbance which happens when transplanting seedlings.

Wait for warmth to direct sow seeds or transplant seedlings and nursery starts. Watermelons have roots sensitive to transplant disturbance, and direct sowing minimizes damage. 

To direct sow watermelons in containers, plan for one to two weeks after the final frost and when soil temperatures reach 70-90°F (21-32°C). Chilly spring nights can hinder growth and inhibit fruiting, and growth accelerates within a few weeks in warm temperatures.

Sow two to three seeds in the center of the pot at ½ inch deep. With evenly moist potting mix, look for sprouts to emerge within 10 days. When three sets of true leaves appear, thin the seedlings so that one singular sprout remains. Clip the sprouts at the base of their stems to avoid disturbing the young roots of the remaining seedling.

Select the Best Types

Opt for varieties that produce compact crops.

There are different types of watermelons, including standard, icebox, seedless, bush, and early maturing. Standards are the iconic beauties that serve a crowd. Icebox is the more diminutive melon that brought a cool treat for farmers on their breaks from the field. Seedless varieties are newer cultivars for easy eating, and bush varieties are smaller with a non-vining habit. Early maturing varieties are ready to harvest in fewer days.

The best watermelons to grow in pots and containers include compact and dwarf varieties, from vining to bush. They’ll produce smaller fruits on manageable vines. Look for fruits up to about seven pounds for easy growing. Some gardeners have luck with larger rounds, up to 12 pounds or more. Longer vining varieties are best left to run on the ground. More compact vines with smaller fruits are easy to trellis and cradle as they grow.

The best small melons are just as sweet and juicy as their larger counterparts. They produce a big yield in small spaces, and the growth habit of the hybrids often overlaps with disease resistance, earlier maturation, and ease of growth.

Grow Vertically

Use a sturdy, trellis, tripod or fence to support the vines and crops.

Watermelons in pots benefit from a vertical support to hold the vines and weighty fruits as they develop. Trellises and tripods are an easy fit. When scaling your trellis, make sure it fits the mature vine length of your variety. Install the support structure at planting, and train vines as they grow.

Use sturdy materials like a heavy-duty tomato trellis. Tripods are simple structures with strong, tall posts tied, secured, or forged at the pinnacle. Train stems to grow up the three arms of the structure and on lateral supports between the poles. 

Tie Off Stems

Their vines and tendrils cling to structures for support but might require tying off to help them climb.

Watermelons have clasping tendrils that cling to supports, but they don’t climb on their own. Tie the stems to the structure every four to six inches or so until they reach maximum length. The stem is ready for tying when young plants show six to eight inches of vertical growth.

Use a piece of twine to loosely tie the stem to the support. Take care not to disrupt blossoms or developing fruits. Remove yellowing leaves from the base of stems as they age to send energy to the upper growth and fruits.

Support the Fruit

You can use a net or cloth to cradle the crop before it becomes too heavy to support itself.

Since stems aren’t strong enough to hold the heavy fruits on their own, cradle the melons for support. When they reach a few inches, use a net, sling, or tie to lift the weight off the stem.

You can buy fruit supports or use strips of t-shirt, onion nets, twine slings, or pantyhose to slip under or around the melon. Flexible and airy, they expand as the melon grows. Tie or clip each end of the support fabric to the sturdy trellis.

A bonus of growing watermelons in pots and vertically is the uniformity of the fruit. The pretty skin won’t show a pale ground patch.

Water Regularly and Fertilize

They require abundant water and adequate nutrients for the fruits to grow properly.

Watermelons need about one to two inches of water per week. Check the soil surface regularly, and water when it’s dry one to two inches below the surface. Reduce irrigation when the fruits are nearly ripe. Near peak ripeness, the fruits stop growing in size but continue to absorb water. With excess water at this phase, the rinds split open and the fruit bursts at the seams.

Too much water near peak ripeness also reduces sweetness. As the melons reach their prime sugar content, extra water dilutes the concentration. Decreasing irrigation just before harvesting helps prevent cracking and splitting.

Melons benefit from added nutrients to boost vigor, blooming, and fruiting. At planting, topdress with a balanced organic granular fertilizer. As the vines approach flowering, switch to one higher in phosphorus to support blooming and fruit set.

High nitrogen is less beneficial at this stage, as it promotes leafy growth over flowers and fruits. Fish emulsion at planting and seaweed and bone meal during flowering and fruiting are mild organic options.

Maintain, Scout, and Harvest

Timing is key when harvesting the fruits.

Other than regular watering, tying stems, and occasional fertilizing, melons in pots are relatively low maintenance. They are susceptible to a number of pests and diseases. The cucumber beetle, the squash vine borer, and the squash bug feed on plant parts and cause damage.

Fortunately, melons aren’t their primary host, but it’s best to separate cucurbits when possible. Fusarium wilt, anthracnose, and mildew are possible diseases. Vertical growth makes scouting easier and problems more evident early on.

When it comes to harvesting watermelons at peak ripeness, there’s a limited window for achieving the optimal flavor and texture. While some fruits continue to ripen after picking, melons won’t continue to develop flavor or increase sugars post-harvest.

For watermelons, the best ripeness indicator is color. Since potted specimens likely won’t have a “field spot” (a common indicator as it transitions from yellow to creamy white), look to skin color. Shiny skin may also lose its luster and become dull, waxy, and rough when ripe.

Ripe watermelons also have a brown, withered tendril or “pigtail” stem at the main vine. And when tapped, the melon should make a “thump” noise. A ripe round sounds hollow and dull with the tap of a finger. Unripe ones sound more metallic with a lighter tone.

Varieties to Grow in Pots

High-performing compact varieties have firm skins and a high sugar content, often with fewer seeds. They also yield more of the small fruits per vine than you’ll get from the larger types.

‘Sugar Baby’

They are ready to harvest in around 80 days.

‘Sugar Baby’ lets those of us who don’t have the garden capacity for the big classic oblongs to grow equally deciduous watermelons. This classically sweet, juicy watermelon is a smaller, more compact variety. The melons weigh in at six to ten pounds and have firm, mottled black-green skin.

‘Sugar Baby’ is an improved dwarf variety with rich red flesh. It’s made to fit in the icebox for cool refreshment on those end-of-summer days.

Harvest ‘Sugar Baby’ in about 80 days. Warm climates may be able to get in two rounds of sowing for a mid- and late-season yield.

‘Golden Midget’

Its flavor is reminiscent of pineapple.

‘Golden Midget’ brings high visual interest to the vine and on the plate. With pale yellow skin that’s smooth and shiny and salmon-pink flesh, the petite globes are showy. They’re also juicy and mildly sweet with hints of pineapple.

The small melons weigh three pounds and are early to mature, ready to harvest in about 70 days. The productive, compact variety from the University of New Hampshire in 1959 is viable not only for pots but also in climates with short growing seasons.

‘Mini Love’

It has short vines that produce abundant fruits.

‘Mini Love’ is an All-America Selections Award Winner for good reasons. Its short vines allow for accessible growing across garden scales. Productive at up to six fruits per plant, ‘Mini Love’ watermelons are crack and split-resistant. The rind is firm but thin for a full, fleshy interior that’s juicy and crisp. A high sugar content yields sweet rewards from bright red flesh.

Each melon weighs five to seven pounds and has few seeds for easy enjoyment. ‘Mini Love’ holds well on the vine and stores post-harvest.