If you’re new to growing watermelons, you’re likely wondering which types might be best to try, exactly what’s involved, and how many watermelons per plant you can expect at the end of the growing season. As it happens, it’s surprisingly easy to coax homegrown watermelons out of your own garden plot or even from a large pot. What’s more, there’s a mind-boggling number of varieties from which to choose, and, whether you opt for an early, mid-season, or late season type, the end result is usually much sweeter than any watermelon you’ve hauled home from the grocery store.
How many watermelons per plant? It depends!
Just how many watermelons per plant can you expect? A general rule is anywhere from two to four per plant. However, the final count depends on plant spacing, genetic traits, your growing conditions, and other variables. (Fortunately, you happen to have a lot of control over most of these variables!)
Factors affecting how many watermelons each plant will produce
How many watermelons per plant you’ll end up with depends on several factors, including:
- Which varieties you choose
- Whether you provide adequate space for each vine
- The quality of your soil—think pH, fertility, and drainage
- How much water and light your plants get
- The length of your growing season
How variety impacts how many watermelons per plant
The watermelon variety (or varieties!) you grow will also influence how many watermelons per plant you’ll ultimately get to harvest. Besides the classic watermelon—complete with striped, green watermelon rind and bright red flesh—there are countless others in varying colors, shapes, and sizes. It’s fun to experiment with different varieties. I love growing yellow or orange fleshed watermelons in my raised vegetable beds. All in all, the general vigor and productivity of watermelons comes down to genetics.
How growing conditions impact how many watermelons per plant
Your local growing conditions and climate also affect how many watermelons per plant you’ll net. For example, watermelon plants need:
- Direct sunlight—Watermelons simply won’t perform in shade. They need eight hours of full sun daily.
- Warmth—Soil temperatures should be at least 60 degrees F (16 degrees C) before you plant hardened-off seedlings outside. That means paying close attention to the average last frost date for your region. Watermelons do best in temperatures ranging from 70 to 90 degrees F (21 to 32 degrees C). I wait to transplant until about a week after that last frost date.
- Enough time to complete their lifecycle—Watermelon plants can take 80 to 100 days to go from seedling to harvest, so plan accordingly. Protecting plants with a mini hoop tunnel early in the season gives them a strong start.
The influence of soil fertility and pH
Watermelons grow best in nutrient-rich soil with a pH of 6.0 to 6.5. If you try to grow plants in soil that is too acidic or too basic, your watermelons may not be able to access the nutrients they need in order to grow healthy leaves and, later, to produce flowers and fruits, so use a pH tester ahead of time as needed.
No pollinators = no watermelons
If you don’t see watermelon fruits begin to set and grow—or if you find tiny, shriveled fruits on your vines—you likely have a pollination problem.
You may have had a similar issue if you’ve if you’ve ever grown cucumbers or squash in your vegetable garden. Like many watermelons, these vegetables typically have separate male and female flowers. If an insufficient amount of pollen is transferred from males to females, the female flowers may drop off altogether or you can end up with small, malformed fruits. To ensure adequate pollination, invite bees and other pollinators to visit by planting pollinator-friendly flowers nearby. Good choices include sunflowers, cosmos, nasturtiums, and sweet alyssum.
You can also hand-pollinate watermelons. To do this, you need to be able to distinguish between male and female flowers. While both look similar, there are important differences. Male flowers, for instance, emerge from straight stems. Female flowers are attached to the watermelon vine by their small, bulbous-shaped ovaries.
To hand-pollinate, look for newly opened male flowers. (They usually open in early morning.) You can collect pollen from the males with a dry paintbrush and transfer it to the female flower. Or, if you prefer, you can remove the male flower from the plant stem and gently rub the male’s anthers against the female’s stigma.
Does vine pruning translate to more melons per plant?
You may find mixed messages about the value of pruning and its influence on how many watermelons per plant you can expect. Gardeners routinely used to cut the ends off of their watermelon plant’s main vine and any young laterals or side branches before fruits appeared in order to spur the plant to branch even more and potentially fruit earlier.
However, this can set fruiting back. Instead, examine individual melons as they form and cull some of the weakest ones. Left with greater access to water and nutrients, the remaining watermelons will be bigger and more flavorful as a result.
The soil moisture level’s impact on watermelon production
Shallowly rooted, watermelon plants don’t do well with “wet feet” or with inconsistent watering. As such, good drainage and regular watering are integral to successful watermelon production. For best results, amend the planting bed with plenty of aged compost—particularly if your soil is very compacted or comprised of heavy clay.
To maximize fruit production, make sure your plants get one to two inches of water weekly. Watering via a drip irrigation system or soaker hose is ideal. Directing water to the root zone in this way helps to keep plant foliage dry, thereby reducing the likelihood of fungal diseases such as anthracnose and gummy stem blight.
Finally, when you get close to harvest time and your watermelons have reached the expected size for their particular variety, avoid overwatering since this can dilute their flavor and damage them structurally.
Can more fertilizer result in more watermelons per plant?
Adding fertilizer can influence how many watermelons per plant you’ll pick—provided you don’t overdo it, that is. By incorporating an all-natural, slow-release fertilizer early in the season, your plants can access nitrogen for green, leafy growth and phosphorus and potassium for flowering and fruiting when they are ready for it.
Watermelon varieties with the most melons per plant
Early season: Sugar Baby—Maturing in about 80 days, extra-sweet Sugar Baby watermelons produce 8- to 10-pound fruits.
Mid-season: Crimson Sweet—Crisp, sugary, and disease-resistant, Crimson Sweet watermelons mature in 85 days with 20- to 25-pound fruits.
Late season: Mountain Sweet Yellow—Produces 25- to 30-pound fruits with sweet, yellow flesh in 95 to 100 days.
Want to learn more about how many watermelons you can expect to harvest from each plant? Watch this video:
Do grafted watermelons make more fruits?
Grafted watermelons—seedlings which have been cut and re-attached to a different plant’s rootstock—potentially can make more fruits. Partly, the outcome depends on the rootstock used and why it was chosen.
For example, commercial grafters might join a watermelon variety with a rootstock intended to promote better disease resistance or one intended to improve overall plant vigor. Certain types of winter squash and bottle gourds are among the most commonly used rootstocks. Grafted plants are more expensive than standard packs of watermelon seeds.
Final tips for growing more watermelons per plant
- Avoid overcrowding—Generally, you can plant two to three watermelon plants together in a single mound. Rather plant in rows? Try two to three feet between plants and five to eight feet between rows.
- Patrol for pests—Hand-pick small infestations of aphids, cucumber beetles, and other pests. Apply an insecticidal soap for larger infestations—just remember this also affects beneficial insects. To keep pests off of your vines post-pollination, use floating row cover or insect netting.
- Pro tip—When fruits do set, place them on a layer of straw or a melon saucer to keep them clean. Not sure when to harvest? Look for these clues. First, the ground spot (where the fruit rests against the ground) will be a creamy yellow color. Also, there should be a (formerly green) tendril which has dried. If you see a brown tendril near where the fruit is attached, that’s another good sign.
Sweet!
Once you have a handle on the basics like the size of your garden space, your soil and climate characteristics, and which watermelon varieties you intend to grow, you’ll have a better sense of how many watermelons per plant you’ll get to enjoy. Remember, watermelons require full sun, rich, adequate spacing, well-draining soil, a consistent watering schedule, and plenty of patience.
Whether you choose a humongous hybrid or the rarest, most compact heirloom watermelon variety, if you follow these best practices, you can be sure to enjoy not only a bountiful harvest, but a sweeter and more flavorful one, too.
For more information on growing watermelons and other vining crops, be sure to check out these articles:
- Growing watermelon in containers
- Growing spaghetti squash from seed to harvest
- When to plant cucumbers: 4 easy options
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