Growing Watermelons on Tomato Cages

We are fortunate to live in Zone 7b where (in theory) watermelons planted in our Kitchen Garden should thrive in our long, hot growing season. Oh, would that it were as simple as that!

Here's a bit of backstory:

Our first year here (2009), we had a couple of rows of tomatoes and peppers in the newly-christened Way Back. That's when it was still a 1/4 acre wasteland of weeds, wild blackberry bushes, and rocks. The soil was pathetic, to put it mildly, having been scraped clean whenever Duke Energy installed the transmission lines overhead; the previous owners had simply ignored this diamond-in-the-rough part of their property. We knew we had our work cut out for us, but I don't think either imagined what a tough-row-to-hoe we'd tackled.

Our next two years (2010 & 2011) were about putting our much-revised 4-year plan into action. We focused on growing the basics like tomatoes, peppers, beans, and squash in the Kitchen Garden, and on getting the soil in better shape. And while the garden we planted in 2012 was more ambitious, medical circumstances caused us to abandon most of our efforts to the forces of Mother Nature. Still, we were headed in the right direction...just not there yet.

Our Kitchen Garden of 2013 was the first "according to plan" version, with cool season crops (followed by a cover crop of beans) in the raised beds of the Box Garden; corn, peas, and pumpkins in the Block Garden; and warm season crops in a 4-year rotation in the four rows of the Row Garden. One of those rows (Row #1 in 2013) was designated for the cucurbit family of cucumbers (grown on an A-frame trellis formed from repurposed lattice panels), cantaloupes (really, muskmelons), yellow squash, zucchini, and watermelons.

I trialed using black landscape fabric as a weed barrier on all of my rows in 2013, cutting X's in the fabric at appropriate spacing to plant either seeds or transplants. My watermelon seeds didn't germinate, so I purchased transplants of Sugar Baby, Crimson Sweet, and Jubilee watermelons. These went in in mid-May, and by 6/26/13 I was reporting in my journal that we had 10 small fruits on flourishing vines.

Unfortunately, some critter (raccoon? groundhog? turtle?) ate holes in every single melon by the end of July. When a few more melons (mostly Sugar Babies) started appearing, I put them inside nursery pots, thinking "out of sight, out of mouth." They/It ate those melons, too. Such a heart-breaking day.

There had to be a better way.

Because we got such good results with the cukes growing on a trellis, I thought the answer might lie in that direction: upward. But I was out of lattice to repurpose. What I did have in abundance was tomato cages. I wondered if they might work.

Moving to Row #2 in the rotation, I "planted" the tomato cages at the same time as the transplants (started from seeds) of Crimson Sweet, Sugar Baby, and Jubilee...again cutting X's in black landscape fabric that covered the row. According to my garden journal, the date was 5/26/14 (much later than intended, due to cooler weather at the beginning of the season).

As the vines grew up, I wrapped and wove them over and around the rungs of the tomato cages. I knew I was going to run into an issue with the weight of the individual fruits, so I was trying to "build" a strong vine system as I went along. Soon the male flowers appeared. Not long after, the female flowers...and the bees...showed up. Imagine my excitement when I took this picture of the first melon of 2014! 

By this time, the vines had grown up well past the top rung, even with my wrapping and weaving, and the fruits were becoming quite heavy, as you can see with this Jubilee (pictured below). And I had begun to research support options in earnest.

While several sites suggested using mesh bags like onions come in, I didn't have those readily available since I grow all the onions we use. Some sites recommended slings made from pantyhose, but I rarely wear pantyhose anymore. I was using a gallon milk jug, perforated in the bottom for drainage and zip-tied to the cage supporting my cantaloupes, but I knew that wouldn't be large enough for a watermelon, even the smaller Sugar Baby (pictured).

I settled upon making slings or little hammocks out of an old summer-weight row cover. I cut 44" lengths of it into strips of about 10-12" in width, knotting them on the ends around the rung above where a melon had formed, securing the ends with clothespins. I knew that the weight would increase as the fruit matured, so I was trying to provide some growing room in the sling.

As the original melons grew, the row cover slings began to show their age. Many had small holes that became large tears, and one melon ripped its row cover in two...sending the now-unsupported fruit crashing to the ground. Another simply cracked open from lack of sufficient support when its sling tore, as seen in this picture. 

At that point, I started making the slings from old t-shirts, which provide much more support. Sling material question solved!

What I didn't realize was just how much the weight of a growing melon would pressure the tomato cage. Thomas had to "retrofit" the cages with support from a steel fence post, driven into the space between two cages, which I then tied to the post. This triage prevented both cages from toppling over mid-season.

I also placed upturned plastic 3-gallon nursery pots under the growing melons nearest to the ground, to give them extra support. And then the rains started, adding extra water-weight to the nearly-ripe fruit.

We harvested 5 melons on 8/8/14: 2 Crimson Sweets, 2 Jubilees, and 1 Sugar Baby. While the CSs appeared to be ripe, I had my doubts about the others. But vine failure, probably due to squash vine borers, led me to try to save the largest of the fruit. Would they be ready to eat?

We chilled a couple and cut into the largest of the Crimsons this morning. When I pierced the rind with the knife, it popped open with a crack...a good sign! And it tasted every bit as good as it looks in this picture. 

So, using tomato cages to trellis watermelons turned out to be a good idea, getting the vines off the ground and providing needed protection from critters for the fruit. The proof was in the tasting!

What will we do differently next year? 

1. For sure, we will sink the fence-post support system at the time of transplanting. 

2. We will definitely use t-shirt strips (12-15" in width) as sling-material. 

3. We will also cut a 4-6" long split in the ends to make them easier to knot around the rungs.

4. I will prune the vines more enthusiastically, especially the side shoots, to keep the plants cleaner and more manageable. With less green vegetation, there will be less pest-pressure.

As always, happy hoeing!