Watermelons are not frost tolerant. Transplant outside after all danger of frost is passed in loamy, fertile, well-drained soil where they will receive a minimum of 6 hours of sun each day. Watermelons produce large vines that spread and take up a lot of garden space, so plant on giving each plant a 4’ x 6’ area.
Plant (2) seedlings in mounds (or hills) of dirt spaced 2-6 ‘ apart depending on the amount of space you have. Mounding the soil helps ensure that the dirt is loose enough for the roots to grow and allows excess moisture to drain away quickly. Cover the hole and water deeply.
Helpful hint: place a stake in the center of each mound to help you locate the hill. As vines grow it is often difficult to tell where the roots are located. This will help with watering as the season progresses as only the roots need to be watered (not the vines).
When seedlings have reached 4” tall, consider mulching the hill and surrounding area to help keep the vines and maturing fruit clean and away from standing water. It will also help to prevent weeds, retain moisture and will keep the soil from being overheated during the heat of the summer. Straw or compost is best.
Once flowers are visible on the vines, water approximately every 3-4 days if dry. However, don’t over-water, as watermelons have a low water requirement.
Watermelon varieties citrullus lanatus
Crimson Sweet Watermelon
Dark/bright green-striped oval 10-12” long fruit.
Sweet, crispy, juicy fruit deep red with few seeds. Very
productive. Each plant produces 3-5 large fruits 15-25 lbs.
Harvest 85-90 days.
Long, oval melon with bright red, very sweet flesh.
Light green with distinct dark green rattlesnake
type stripes. 1” thick rind. Grows to 11”x 25”.
Open pollinated. Harvest 95 days.
Moon and Stars
Popular heirloom with dark green rind and yellow spots.
Sweet flavored flesh is dark red. Large oblong fruits usually
10-15 lbs. can grow up to 40 lbs. Requires warm temps to
set fruit. Harvest 95-100 days.
Sugar Baby Watermelon
Heirloom variety. Early producer. 6-8” fruit weighs
8-10 lb. Thick, dark green skin. Firm, sweet red flesh
with large, dark brown seeds. Space-saving, compact
vine. Harvest 70-80 days.
Watermelon culture –
Watermelons are a vining, flowering plant originally from south Africa. Watermelon is loosely considered a type of melon, although not in the same genus. They have a smooth exterior rind which is usually green with dark green stripes and a juicy, sweet interior flesh – usually deep red to pink. Watermelons are more than 90% water and a good source of vitamin C.
To test the ripeness of a watermelon, thump it. A dull, hollow sound means that it has ripened. Also, check the underside––it should have turned from white to pale yellow. You can also check the nearest curly tendril near the watermelon’s stem. If the watermelon is ready it will have dried and turned brown. Harvesting them before they’re ready will result in less flavorful watermelons, but waiting too long will cause them to over ripen. Use a sharp knife to cut the watermelons from the vine. Freshly harvested watermelons will keep for about 7-10 days.