How to plant and grow watermelon

PLANTING, GROWING, AND

HARVESTING WATERMELONS

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!

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.

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.

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. 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.

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 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 seedling 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.

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.

General Care Tips

Mulching with black plastic 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).