Watermelon Seeds - Charleston Grey

Pick a spot outdoors where your plants will get full sunshine- at least 8 hours during the day. Melons are a heat-loving, summertime crop and the ground temperature must be above 70° before you begin planting or else the seeds will not germinate. 

Melons prefer a neutral pH, between 6.0 and 7.0, and will benefit from a few inches of added compost for nutrients and incorporating a source of available calcium before planting to help combat blossom end rot which can sometimes effect melons when the soil is lacking. 

Loosen your planting area gently with a fork, and planting on a hill made with good soil or compost will help define your planting rows and allow for extra drainage. Leave at least a 4x4’ area per plant, and expect that the vines will push beyond that and intermingle with each other. If you can allow more room, the extra air circulation will help with the health of the plants.

If you live in an area with long winters and short summers, you should consider starting your seeds inside 4-6 weeks before you would plant them out. Pre-warming the soil with black plastic or landscape cloth may help extend your season as well. 

Sow 5-6 seeds per hill. Your seeds should be planted between 1-2” below the surface. When your seeds are a few inches tall, thin to your strongest 2-3 plants per hill. If you are planting seedlings that you started growing indoors, or if you purchased seedlings from a nursery, plant 2-3 seedlings per mound. Water well when you are finished planting. 

If you aren’t using landscape fabric, protect your seedlings with mulch to preserve moisture and regulate soil temperature. 

Water 2-3 times a week if rain doesn’t do it for you. Melons need 1-2” of water a week to develop fully, but start to pull back and water less as the melons start to size up. Over-watering at this stage can cause rot and/or melons that are less sweet. 

Fertilize your plants every 3-4 weeks with your favorite gentle, organic fertilizer. Compost tea is our favorite for growing melons here. 

Watch for any white, powdery patches or spots the leaves or stems of your plants, which are signs of powdery mildew. If your plants are infected with powdery mildew, remove all plant parts that appear affected, and spray the rest of your garden with an organic fungicide or diluted copper spray. Please follow the directions very carefully when applying any treatments. 

Monitor for aphids and cabbage worms which could bother your plants as well.

Your melons will be ripe and ready to eat by late summer or early fall. Being able to tell when your melons are ripe is something of a practical science. One way to tell is when you can smell the melon through the skin. Once they’ve been picked from the vine, melons will get softer, but not sweeter. If you don’t eat your melons shortly after harvest, they can be stored in the refrigerator for up to 2 weeks.

Watermelon, Citullus lanatus

Pollination, insect; Life Cycle, biennial; Isolation Distance, ½ mile 

An insect pollinated annual, watermelons will cross readily with each other and citron melons, but not with other types of melons. Fruits will usually have a mix of mature and immature seeds inside and you can separate these by hand, or we prefer to put them in water and the non-viable seeds will float. Skim these off and continue to stir and skim until no more seeds float to the top. Rinse the remaining seeds well and spread on a screen or many sheets of newspaper and allow drying thoroughly before storing. This can take 2-4 weeks depending on humidity in the air.