How to Grow Watermelon
Watermelons are surprisingly easy to grow as long as the plants have plenty of room to spread, good drainage, lots of sunlight, and a sufficiently long growing season. Gardeners in northern climates should choose early ripening varieties. (This is where I get my seeds. They have several varieties of watermelon to choose from)
Position for Growing Watermelon
**Location is super important for growing watermelon: pick a spot that gets 8-10 hours of sunlight per day that is protected from high winds.
**Plant them 6 feet apart in a place that will stay damp: work in plenty of compost and mound the soil into small hills. Plant the seeds in these hills and cover with mulch or some sort of weed cover (like this) to maintain moisture and soil temperature.
Propagation of Watermelon
**To ensure proper germination, wait until your soil temps are at least a steady 70 degrees Fahrenheit before planting your seeds.
**Plant approximately 2-3 weeks AFTER your last frost date.
**You can start seeds 4 weeks before you plant to plant them in the garden if you want, though they might not start unless you have a heating pad (they will not germinate until the temps are above 70 degrees Fahrenheit!).
**Otherwise, just directly sow the seeds in the soil (in those mounds that are 4-6 feet apart!)
Maintenance for Watermelon Plants
**Watermelons are heavy feeders, so if you do not have rich soil, give them some boosts of good fertilizer (like this) or some extra compost throughout growing season. Start them out in a compost-rich and nutrient-rich soil as well.
**Watermelons need plenty of water to grow well, at least 1 inch of water per week. If they do not get enough water, it can cause a calcium deficiency which produces blossom-end rot.
**Keep an eye out for cucumber beetles. They do the most damage early in the season, when your watermelon plants are young. You can protect your plants from cucumber beetles by covering the plants with floating row covers (like this). Simply remove the covers when the flowers appear for pollination purposes.
**A good companion plant is radishes: they help prevent some diseases (like fusarium wilt) and keep the cucumber beetle population down. Click here to learn how to grow your own radishes.
**If the top of your watermelons get yellow, they are getting sunburn. Simply cover them with a cloth or basket.
**When your fruit appear, consider putting straw, extra mulch, etc. under the fruit to help keep them off the wet soil and to encourage proper air circulation.
**If space is a problem (since each watermelon needs 6 feet of space!), consider vertical gardening. You CAN trellis your watermelons, as long as you train them to climb. When your vines begin to run, train them up the trellis. You will need to tie the runners to the trellis to encourage them. If you use a trellis, you will need to support the watermelon fruit as they grow. Use cheesecloth, nylon stockings, old sheets, etc., to make slings under the watermelon fruit.
Harvesting Watermelon from the Garden
**Watermelons do not further ripen when they are off the vine. This makes harvesting season a bit tricky.
**There are many theories to consider when you are trying to figure out if your watermelon is ripe and ready to eat:
- When your watermelon flowers are in full bloom, they will be ripe for eating in 5 weeks.
- Where the stem of the watermelon meets the main vine, there is often a curling tendril. If this tendril is brown/dry, your melon is probably ripe. If the tendril is green, the watermelon is probably still growing.
- Look at the underside of the watermelon: if it’s white instead of yellow, your watermelon probably isn’t ripe yet (this can depend on the variety, however).
- Gently knock on your watermelon (I usually flick it instead): if it has a deep, hollow sound, it is probably ripe (the sound is hard to describe, but trial and error will help you figure out the best sound).
**When your watermelon is ripe, snip them from the vine with gardening shears.
**Store uncut watermelon at room temperature to keep them super tasty. ONLY put them in the fridge when they have been cut open!
**Saving seeds for future crops works best with heirloom watermelon seeds:
- Scoop out the seeds and place in a wire mesh sieve. Pour running water over them and gently rub away the stringy fibers.
- Place cleaned seeds in a bowl of water and stir a few times. Throw away the floating seeds: they are sterile/immature/etc. Stir a few more times and repeat the process of throwing away the floating seeds.
- Drain the remaining seeds. Line a cookie sheet with waxed paper, spread the seeds in a single layer on the waxed paper and place in a sunny spot outdoors to air-dry.
- Occasionally stir the seeds a bit to make sure all of the sides are exposed to air and sunlight for even drying.
- At the end of the day, bring the seeds indoors and continue to dry them for 1-2 weeks. Stir daily for even drying.
- Since watermelons have such thick seeds, you need to make sure they are thoroughly dry before storing them: humidity, rain, etc. can add on a few more weeks of drying.
- Store them in a dry, dark place until next summer.
Will YOU grow Watermelon this year? Let me know in the comments! 🙂