Growing Watermelon

Growing Watermelon

Growing watermelon it’s great for kids during those summer months. In the northern states you just have to use transplants, as the season may not be long enough. Usually, around June 1st is a safe time to get all your summer vegetables in without having to worry about those cold evenings. Watermelons are true summer vegetables that need lots of sun, warmth, nutrition and a good amount of moisture.

How to Grow Watermelons

Watermelons grow very quickly once the weather warms up. They need lots of water and should be  planted with a good amount of humus. There are many varieties today that range from seedless and small sized fruit, to short season and heirlooms. There are bush varieties that are great for small spaces and can be grown in containers, or some types that are climbing or vine, which can take lots more room for producing large fruit.

Garden the Organic Way is great for beginners and seasoned gardeners.

For best results in the northern areas, choose varieties that are short season and use transplants. Even if growing in warmer climates, the use of transplants will have you producing a much earlier crop than if you go direct seeded. Also, to increase the season, you can place these outdoors and then put a fabric row cover to keep them warm. Mulching them is also very helpful to keep the soil warm and maintain even moisture. It’s important to remove the fabric cover once the plants start to send flowers, in order to allow pollination to take place. Learn more about this family and many more vegetables from my book ‘Garden the Organic Way‘ 

Proper Spacing

They need anywhere from three feet to twenty feet of room for them to spread. It all depends on the variety you choose.  Therefore, look at the spread requirements and how it compares to your situation.  Unless you have the space or the means to trellis them, choose smaller varieties.

Planting Seeds or Transplants

Best to direct seed only after the soil has warmed up to 70° F. The seeds germinate in very warm weather, like high 80’s to 90’s, in just a few days. If the temperature is in the 70’s, then germination can take about a week or even longer. One way to speed the germination is to soak them overnight and, once planted, place them under a row cover until the weather gets real warm. To read about starting seedlings see the blog

Growing watermelons under row covers to protected against insects and keeping them warm.

Start seeds indoors two to four weeks before placing them outdoors. This helps to get ahead of the season or, in some locations, to give the plants enough time to produce. See YouTube video on hardening off

You can place up to three plants per hill if growing the non-spreading smaller varieties.  Otherwise it is best to do just two plants per hill to give enough room for the vining varieties that spread. Plants need to be kept properly watered until they start to flower.


You can grow watermelons under trellis to conserve space and also to help with air circulation, which in turn helps prevent diseases. Trellis them against a fence, especially if they are the smaller fruit varieties. Trellising watermelons will not work with the large traditional varieties that can weigh over twenty pounds. You can use an old pantyhose, if someone still wears them, or netting or some type of fabric to hold and anchor the fruit to the fence or trellis. Usually, if you are trellising against a fence, the fence will help support the netting.

When To Harvest Watermelon

It is important to harvest watermelon only after they are ripe as they don’t ripen after harvest like other fruits. The underside of the fruit where it touches the ground develops a yellow white light color. When  they trellised then it should be full and have equal symmetry. When you tap it with your thumb there is a hollow sound that is heard, like a large deep sound from a drum. Lastly the stem attached starts to turn brown.

Insects and Diseases – It is tough to control these when growing organically, but these few tips should be quite helpful. In the early stages of growth it’s important to protect the plants from striped or spotted cucumber beetles that can easily devour your plants as well as transmit bacterial wilt disease.

The squash vine borer can readily attack them as well. The adult moth lays its egg at the base of the plant. Within a short time, you would see a saw-dust like material oozing out from the stem at the base of the plant. You can do surgery to the base by cutting lengthwise versus across the stem. Then you can remove the grubs. Afterwards, tie a small piece of cloth, like cheesecloth, to the base to keep it closed.

The flea beetles can also be a problem. If you get enough fruit forming that you are comfortable with and want to protect from flea beetles, you can place the row cover again.

I like to use a cloth row cover until the plants are older and ready to bloom. This way, it will protect against all of the above insects and give the plant enough strength to survive the balance of the season.

Cucumber mosaic virus is transmitted by cucumber beetles and by aphids. The best control is to use resistant varieties and to remove infected plants as soon as any signs appear.

For powdery mildew, the best control is not crowding the plants and giving plenty of circulation. It is best to water early in the morning. You can get ‘Garden the Organic Way’ as an eBook http://Amazon- Garden the Organic Way