Watermelon Fast Facts
Cool or warm weather: Warm
Size: Large
Sun: 8 hours
Days til maturity: 80-100 days
Water: Consistent
Original or Leaf GreenStalk: Original
GreenStalk level: Place below smaller plants
Plant support needed? Yes
Watermelon is easily one of the most iconic and nostalgic symbols of summer. Sweet, juicy, red flesh and striped green skin– the thought alone transports us to sunny picnics and long summer days. Growing it in a GreenStalk garden has many benefits. We’ll show you how to plant, grow, and harvest watermelon so you can enjoy the sweet taste of summer from your garden.
Sugar baby watermelon vines growing in a GreenStalk Vertical Garden.
Planting and Growing
Watermelon is a warm-season crop that can be grown from seed or starts. We recommend compact varieties with vines that grow to a more manageable size. We have had a lot of success growing the sugar baby variety. You could also try mini love or yellow petite.
If you cannot find a compact or bush variety at your local nursery, you can start from seeds. Whether you direct sow into your GreenStalk or start your seeds indoors, we suggest growing one plant in every other pocket in the GreenStalk Original Vertical Planter. Mist seeds by hand in individual pockets until you see the first set of true leaves, then water through the top reservoir. Regardless of variety, watermelon loves warmth, so plant after all danger of frost has passed.
Give your watermelon plants at least eight hours of sun and keep the soil consistently moist. Plants need love which means: check on them daily!
The average growing season for sugar baby is 80-100 days (compared to 120 days for a full-size watermelon) but always check your seed package for growing information and maturity dates.
To prune or not to prune
Pruning is not necessary for watermelon vines. However, you certainly can trim the side shoots so the plant can focus energy to fruits growing along the main vine. Or you can prune if the vines feel they’re getting unruly. It’s entirely up to you.
Powdery mildew is less common in a GreenStalk, where plants are watered at the root and not on the foliage. However, if the humidity in your area causes those notorious powdery white leaves, you could prune out affected vines in effort to keep it from spreading. We like to follow up with a neem oil spray.
In any case, be careful not to cut the tip of the main vine or you will not get any more fruit than what’s on the vine at that point.
Pollinators and Pests
Your watermelon flowers need to be pollinated to produce healthy fruit, so welcome in those friendly pollinators. Bees can’t resist yellow watermelon blooms, but it doesn’t hurt to lure more with flowers they love. Consider planting verbena, lantana, or other pollinator-friendly flowers in the surrounding or alternating tiers.
Some pests to watch for are aphids and cucumber beetles. Regularly check the vines and under leaves. Remove pests by hand or use an insecticidal spray.
Resting watermelon in an empty pocket while it grows.
Support
If you’re wondering how to support those long vines and heavy fruit in a vertical garden, the GreenStalk Plant Supports make it easy! Train your vines along the support and if needed, tie the vine to the support with soft, stretchy pieces of fabric. As those gorgeous green fruits grow and ripen, you can use nylon fabric to tie up the fruit like a hammock to the Plant Supports. You could even tie them to the loop on our Plant Markers! In no time you’ll have a beautiful little watermelon with no rotten undersides.
You may opt to grow watermelon in the bottom tier and let the vines grow on the ground around your GreenStalk. And that’s great too! Just place a bit of straw, mulch or even cardboard under your melons to prevent direct contact with the soil. Gardening should be fun and experimental. As long as you’re growing healthy plants, there’s no wrong way to do it!
Approximately seven weeks after planting Sugar Baby Watermelon seeds.
Harvest and Storage
Keep an eye on the tendrils of your watermelon plants, they will give you a hint when the fruits are ripe and ready to harvest. If the tendril closest to a fruit is green, the fruit is likely not ready to pick. If you are in range of the maturity date for your variety and the tendril closest to the fruit is brown and has died back, it should be safe to harvest your watermelon. Note that, unlike some other fruits, they do not continue to ripen (or sweeten) after harvesting.
Some people like to stop watering a week or so before harvesting watermelon, claiming it concentrates the sugars. You can give that a try, but be mindful of any other plants in your GreenStalk garden that might be thirsty!
Once harvested, watermelon lasts for about ten days at room temperature. Once cut open, refrigerate and enjoy within about four days.
If you are growing watermelon in your GreenStalk garden, let us know! For more information about growing in your specific climate, check out your local extension office. We’re here to help you grow — just email us at support@greenstalkgarden.com.
Happy gardening!
