I grew some heavenly seedless watermelons last year. They were the size of a large cantaloupe with a dark green, striped rind and beautiful, deep red flesh — just the way a good watermelon should be. As sweet as the sweetest watermelon you've ever tasted, and every delicious bite was undisturbed by a bothersome seed to have to spit out. Plus, they sold very well at the farmers market — we were even able to ask for more for a small, seedless watermelon than a larger, seeded watermelon.
Last summer was the first time I ever attempted to grow these watermelons. I selected ‘Solitaire Hybrid’ carried by Totally Tomatoes. I wanted a small, red-fleshed variety, and this one seemed like a good choice. I used a no-till approach to preparing a patch for my watermelons. In early spring, I heavily covered a 10-by-30-foot piece of fertile ground where fescue grass grew with recycled paper feed bags and old ryegrass hay. By the time the plants were ready for transplanting, the ground was mostly workable, with just a few hard pieces of sod to remove during planting.
The package of seeds came with ten seedless seeds, and then a packet of pollinator seeds. When growing seedless (triploid) watermelons, you must have a normal (diploid) watermelon growing alongside to provide the pollination. The pollinator can be any watermelon as long as it is blooming during the same time frame as the seedless variety. Since this one was a smaller, shorter season variety, ‘Sugar Baby’ watermelons made a good pollinator choice.
Seedless watermelon plants are less vigorous than normal ones, and should be started indoors and slowly hardened to the outdoor conditions. Expect to keep them indoors four to six weeks, and to plant them outdoors no earlier than mid-May. Seedless seeds are more expensive as well, and it is good to take care when germinating them. I have good luck starting seeds in soil on top of my upright freezer: It stays warm there and is a perfect environment for germination. Any area whether dark or light, as long as it's close to 80 degrees Fahrenheit consistently, will speed germination. Using jiffy pots with a good potting soil works very well.
As soon as the seedlings appear they should be closely placed under grow lights or fluorescent bulbs. Keeping them in a cooler environment at this point will also help them not become too leggy, which can be a problem for any plant of the watermelon family. I transplanted them outdoors after they had their third or fourth leaf and had been hardened-off (setting the plants outdoors for longer periods of time everyday for a week).
I made hills about five feet apart through the center of the patch. For each hill, a one-foot area of soil was worked and amended with a small amount of decomposed hay/manure mixture from where the cattle ate hay all winter. One seedless plant and ‘Sugar Baby’ pollinators were planted in each hill. The ‘Sugar Baby’ melons were planted as seeds at this time, and because those seeds are easily acquired —and cheaper than the seedless variety — I placed three seeds in the hill and then thinned the smaller ones after they came up. ‘The Sugar Baby’ plants took off quickly and were always more vigorous and healthier looking than the seedless variety.
They all did grow and set on plenty of fruit, and both varieties did very well. There were about twice as many ‘Sugar Baby’ melons, but there was a good harvest of seedless as well. It was also a good long crop, lasting until late summer. Even better, the plants thrived in the mulched area with little watering.
I am thinking of growing seedless watermelons again this summer. But I wrestle with some concerns about these plants. They grew beautiful, yummy produce that was very marketable. Yet, it seems a little odd to grow something that has been bred to defy its most internally motivated job: to procreate by making seeds for the next generation. I realize that this is just a very intricate form of hybridization, and I have never had a problem with using hybrids, but I'm not sure how I feel about this. Is this a technological advance that we should just appreciate for what it is, and not overanalyze, or are we taking too much nature into our own hands? Is it more important for us to respect the plants’ need to reproduce and do our job of spitting out the seeds?
With all the continual scientific advances made with plants and horticulture in general, it will always be up to us to be thoughtful and responsive with our concerns and beliefs. But, wherever your thoughts and feelings lie, look forward to the hot days of summer and cold, juicy, sweet, fresh watermelon...seeds or no seeds.