Should watermelon be grown on a trellis?

Answer 1

No. Watermelons should be grown on the ground because the weight of the fruit will cause the plant to break if grown on a trellis.

Smaller varieties can easily be grown on a trellis. The natural motion of the plant, due to air circulation mainly, will have the same effect on the vine as working out does to the human muscle. In effect the vine will grow stronger to support the weight of the fruit. Also, after the plant has set a maximum of 4 fruit the main vine should probably be pruned to "encourage" the plant's energy go towards the fruit. Just snip off the main line growth. This will encourage branching, which is beneficial for the added leaf growth. These are the factories that supply the fruit with nutrients. The sole focus of an annual plant is to set fruit and produce seed. However, as long as conditions are met the plant will strive to produce more and more. Exactly the opposite of the human plant who just consumes more and more. There are many hybrid varieties in the 10 pound and under category that are wholly suited for container gardening. Consult local extension agents for advice on which grow best in your area. BTW - I'd say at least 10 gallon containers would be recommended at minimum. With chemical methods each container "might" support two plants. Use a strong trellis that's anchored firmly, preferably to something solid, not just stuck in the pot.