When finding a support for watermelons along a garden trellis you have to keep in mind that a watermelon is one of the heavier fruits. It is to your advantage to grow watermelons off the ground. When growing along a trellis, watermelon tends to rot less often, take up less space, and make breakage less likely to happen. In addition, animals in your garden will be less likely to destroy them.
Step 1 - Put Posts in the Ground
Hammer into the soil steel T posts. Make sure the posts are about 5 feet apart from one another. Make sure the posts are deep enough into the soil so they won't loosen later on when supporting the watermelons. You will want about 6 or 7 steel posts.
Step 2 - Fill Up Buckets of Concrete
Mix concrete into plastic buckets. Follow the instructions on how to mix concrete. Next, you will set posts in these buckets. Make sure to put the buckets fairly deep in the ground so as to support the trellis. The more secure the buckets are in the ground, the less likely you will have to repair them.
Step 3 - Stringing Wires
From one post to another, string wires. You want to use stainless steel wires to prevent the wires from rusting from the rain. Next, take pliers to twist the ends of the wires around the posts. Make sure the wires are snug for support. The first wire should be about 10 inches above the ground. You will repeat this until you have wires running at different intervals from the bottom of the ground leading up to the top of the post. You want the wires to be evenly spaced out so watermelons can grow at different lengths.
Step 4 - Planting Seeds
Plant 2 or 3 watermelon seeds about 3/4 inches deep. These should be between each of the two posts.
Step 5 - Weaving the Vines
Once the watermelon begins to grow and vines sprout, you want to weave these vines onto the wires so the vines start to grow upon them.
Step 6 - Make Slings Out of Fabric
Make slings to support the growing watermelons. From old towels, cut strips that are 7 inches wide. Also, cut strips that are 14 inches wide for larger watermelons. The strips should be long enough so as to be secured firmly to the trellis.
Step 7 - Positioning the Sling
Under each watermelon, tie a sling underneath it for support.
Step 8 - Re-Positioning the Slings
As the watermelons begin to grow, you will need to replace the towel slings with largers ones to support the weight of the watermelons.