For optimum yields plant watermelons 2 feet apart in rows with rows spaced 5 feet apart. This gives one watermelon plant 10 square feet of space. Tighter spacing will result in smaller watermelons and less overall yield and wider spacing will give larger watermelons with less overall yield.
For most commercial farmers high overall yields of watermelon varieties they’ve chosen as marketable is the objective. Different market options include big picnic watermelons with seeds, seedless varieties, small personal size watermelons, or yellow & orange fleshed varieties.
There are different types and varieties of watermelons with the main three categories being divided by weight as personal less than 5 lbs., icebox 5-10 lbs., and picnic size >10 lbs.
Here are two studies done on plant spacing in watermelons that I will cite a few times throughout the article.
- “In Row Spacing Influences Triploid Watermelon Yield and Crop Value”
- “Yield Response of Watermelon to Planting Density, Planting Pattern, and Polyethylene Mulch“.
How Far Apart to Plant Watermelons In a Raised Bed
In a raised bed that measures 4’x 8′ plant watermelon plants every 2′ along the 8′ wall. So that would be four watermelon plants in a 32 square foot bed giving each plant 8 square feet of growing space.
There are bush watermelon varieties that are semi-vining plants more than bushes. These can fit into sections of four square feet but there are less varieties to choose from than traditional vining watermelons.
How Many Watermelons to Plant Per Container
You want to give watermelon plants 3-5 gallons of soil apiece. So if you have a 5 gallon container plant one watermelon plant, if you have a 10 gallon container plant 2-3 watermelon plants in it, and so on.
If you’re planting watermelon seeds plant 2-3 seeds for every 1 plant you want and then thin down to 1 plant once the plants are about 4″ tall. Thin down by picking the most well developed of the 3. If you’re transplanting just plant one plant per spot.
If you have the space to let the watermelon vine sprawl out on the ground it will grow well like that. If you don’t have the space you can use a strong trellis next to the container and train the watermelon vine onto the trellis.
When growing a watermelon vertically on a trellis there are two things to consider. One is the tendrils of the watermelon vine are not strong enough to climb the support naturally so garden ties of some kind need to be used to train the vine up it.
Next is the size of the watermelons. As watermelons grow on the vine attached to the trellis each fruit needs to be supported by a make shift hammock attached to the trellis. Choosing a watermelon variety that produces small watermelons can make this easier.
You can use netting or any breathable material to support the weight of the watermelons so they don’t fall off the vine too early.
How Deep to Plant Watermelon Seeds
Plant watermelons seeds 1/2″ to 1″ deep outside and in pots or starter trays plant them 1/4″ to 1/2″ deep. When transplanting watermelon plants outside plant the root ball 1/2″ under soil.
Water after planting the seeds or plants gently from above or if planted in a starter tray water from below.
How Plant Spacing Affects Watermelons
More space per plant will lead to plants producing more watermelons per plant that are bigger in size. Tighter spacing leads to smaller watermelons and less fruits per plant. In general, total watermelon yield by weight will be higher with tighter spacing.
Corn is an extremely important crop in the US and globally. Lots of studies have been done to increase corn yields.
Corn planted in the field will generally have one ear of corn per plant. But, corn plants on the edges of fields will often have multiple ears on them. This is because of increased access to sunlight, water, and nutrients.
More space makes for a corn plant with more ears of corn on one plant. Farmers have found out that tighter spacing with more plants will lead to greater overall yields. It’s the same for watermelons.
Watermelon Variety & Spacing
Look for bush variety watermelons to save on space. These grow like a semi-vining plant more than a bush. Bush type watermelon varieties grow 2-5 feet long and with foliage that is about a foot tall.
Some of the most popular watermelon varieties are available as a bush type including Jubilee, Sugar Baby, Charlston Gray. If you want a wider selection of watermelon varieties but your tight on space growing watermelons on a trellis can make that possible.
In the study by North Carolina State they suggested that if you’re growing a variety that has small watermelons under 10 lbs. that tighter spacing could be used. The study said “spacings as close as 0.45 m2/plant could be used.” This is a space of about 18″ x18″.
I don’t think I would try and grow a watermelon in that tight of space as a gardener because I’d worry that some of the plants would not produce fruit. What I take away from that is that if you don’t mind having small watermelons you can use tighter spacing.
Planting Watermelons In Hills/Mounds
Sometimes gardeners like to plant things in mounds, especially vining plants. To make a mound you move enough dirt to elevate a spot 8″ or so and at whatever diameter you want the mound to be. The benefit of mounded dirt is increased soil temperature and drainage, no puddles of water.
I’ve found that mounds do not use garden space as efficiently as rows because I end up with less plants in an area. To get the benefits of hills/mounds in a row mound up dirt in a row.
Watermelon Spacing in Square Foot Gardens
Square foot gardens are a form of intensive gardening that divides a garden, usually raised beds, into individual square foot sections. This is commonly done literally with irrigation hose, wood trim, or metal wire sectioning off the raised bed into square foot sections.
Square foot gardening usually leads to better space use because you can see what square foot spots are under utilized and know your options for filling them. Square foot gardening commonly uses inter-planting with different plants in one bed and this is good to keep pest and disease of one plant from bothering a whole bed.
Square foot gardening uses recommended plant spacing to figure out how many of a given plant can go in one square foot. Recommended space between rows is thrown out the window.
A watermelon plants recommended spacing is 24″ so they are given four square feet per plant. If you use a trellis a single watermelon plant can fit into square foot. Here are some other examples.
|Plant||# of Plants Per Square||Space Between Rows|
|Baby Leaf Spinach||32||N/A|
|Melon||2 squares per plant||N/A|
Please comment below about your thoughts or experiences with watermelon plant spacing.