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5 Things You Need to Create the Best Soil for Watermelon

If you could sum up the taste of summer in one fruit, the watermelon probably comes to mind. Homegrown watermelon is the perfect treat on a hot summer day.

The Best Soil for Watermelons

Do you want to grow watermelon in your garden? A plentiful return on your efforts starts with the best soil for watermelon growth. Read on to learn how you can prepare the dirt in your watermelon patch or container for growing massive, sweet fruits!

What is the Best Soil for Watermelon?

Starting Your Soil Mixture:

Soil Acidifier

Espoma Organic Soil Acidifier 6 Lb.

Do you want prolific harvests of homegrown watermelon? Nothing beats a juicy slice of ripe watermelon on a hot day. To take advantage of the many health benefits of watermelon, you must use the best soil mixture with a perfectly balanced texture and composition.

The best soil for watermelon plants should contain essential nutrients and the correct texture to promote strong roots and healthy stems and leaves. Nutrient-rich soil helps your watermelon plants grow and produce juicy watermelons with deliciously high sugar content.

Like many crops, watermelon plants prefer soil that is loose and loamy. Sandy-loam soil comprises over 50 percent sand and less than five percent clay. This mixture promotes aeration in the earth, which helps control moisture and temperature.

Air acts as insulation in sandy-loam earth, which is critical for watermelon growth. These vining plants require moist, warm soil in order to flourish. In fact, watermelon plants need sunny locations as much for the soil temperature as the sunlight.

Melons thrive in slightly acidic conditions. The best soil for watermelon should have a pH balance between 6.0-6.8. Consider adding a soil acidifier if the planting location is particularly alkaline.

To achieve a suitable soil composition, you should start by analyzing the ground where you will be planting watermelon seeds. You can conduct a soil test before you add any amendments, so you will be sure to mix the best soil for watermelon.

Preparing Your Soil:

What to Mix

Miracle-Gro Garden Soil All Purpose: 1 cu. ft., For In-Ground Use, Feeds for 3 Months, Amends Vegetable, Flower and Plant Beds

Keep in mind your planting destination when seeking nutrient-rich, loamy garden soil for your watermelon plants. Are you planting watermelon seeds in-ground or in a raised garden bed? If that is the case, you can achieve optimal soil conditions by mixing lightweight potting soil with standard garden soil.

Start by digging a hole about one foot wide and one foot deep. If you have exceptionally hard-packed clay earth, you may want to dig a larger hole to provide more space for developing roots. Loosen and break up the native soil along the bottom and sides with a hoe or shovel.

Next, grab a bucket and combine equal parts in-ground garden soil and enriched potting soil. You might add one cup of sand to each gallon of dirt for extra drainage and soil aeration if needed. Moisten the mixture until it is damp and crumbly but not soggy. Fill your planting hole with the mixed sandy-loam soil and water thoroughly.

At this stage, you can mix in some starter fertilizer and let it soak into the earth for a day or two before planting. This is especially helpful if you are transplanting watermelon seedlings, as it provides adequate nutrition without risking nutrient burn from direct fertilizer application. 

Fertilizing the Soil:

What to Add

Growing watermelon in a garden

To truly create the best soil for watermelon growth, you should pay careful attention to the available nutrients. Not all dirt is the same, so starting off with a soil test is wise to determine what needs to be added.

You must be mindful of the growth stage of your watermelon plants to ensure soil amendments are added at the proper times. Watermelon plants need different minerals throughout the growing season. You can get away with using a balanced fertilizer all year, but you will see better results if you cater to the plant’s current needs.

Should you choose organic fertilizer for your watermelon plants? Whether you purchase organic or synthetic fertilizer is up to your personal preference. Either type of fertilizer delivers the necessary nutrients that will lead to healthy watermelon plants.

Before you add any fertilizer, you might want to boost the earth with beneficial microbes. Nature Hills Root Booster is an all-in-one additive that enriches the soil and adds living fungi and bacteria that help roots absorb nutrients.

Fertilizer for Watermelon Plant Development

Quality fertilizer includes three primary nutrients: nitrogen, phosphorus, and potassium. Young plants require extra nitrogen to fuel the production of healthy stems and leaves. The best soil for watermelons at this stage should include additional nitrogen.

From a seedling’s first set of true leaves until it starts flowering is called the foliage stage. To promote strong plant development, you should amend the soil with a high-nitrogen fertilizer.

Dr. Earth Natural Wonder Fruit and Berry Fertilizer Concentrate has the perfect ratio of nitrogen, phosphorus, and potassium needed to support the growth of your watermelon plants through the foliage stage.

Fertilizer for Watermelon Fruit Production

FoxFarm Happy Frog Fruit & Flower Dry Fertilizer 50 Pound Bag, FX14655

Once your watermelon plant is fully mature and ready to reproduce, it reaches the flowering and fruiting stage. During this period, its nutritional needs change significantly.

When plants are gearing up to produce fruit, they do not need as much nitrogen. Instead, the fruiting and flowering process requires extra phosphorus.

In order to supply your watermelon with the necessary ingredients for a bountiful harvest, you’ll want to look for a fertilizer with less nitrogen and more phosphorus. 

Adding FoxFarm Happy Frog Fruit and Flower Dry Fertilizer to your melon patch creates the best soil composition of key minerals and helpful microbes to promote the growth of juicy watermelons.

The Other Best Soil for Watermelons:

Growing in Containers

FoxFarms 733266 Soil, Strawberry Fields Potting, 1.5 cu

If you are limited on garden space, you might think you can’t grow giant, delicious watermelons. While it is true that watermelon plants can grow to enormous sizes, you can still successfully grow them in containers.

To start with, you will need a large pot around 18 inches deep and at least a foot wide. When planting outdoors, watermelons need around six feet of space between seeds. With this in mind, you should try to provide your potted watermelon with as much space as possible.

When it comes to growing in containers, picking the best soil for watermelons requires special care. Ensure you select enriched potting soil with exceptional moisture control. FoxFarm Strawberry Fields Fruiting and Flowering Potting Soil is an ideal choice to keep your melons hydrated and nourished all season long.


Watermelon growing

What fertilizer is best for watermelon?

Watermelon plants need different fertilizer compositions depending on their stage of growth. Young plants that are still putting most of their energy into foliage production need lots of extra nitrogen. Nitrogen helps plants build healthy roots, stems, vines, and leaves.

Once the plant is fully mature and ready to reproduce, its nutritional needs change. The plant will divert energy from foliage production to fruit development. 

This process is phosphorus intensive but does not rely as much on nitrogen. For this reason, specialty fertilizers are available for fruiting and flowering plants in this stage. These fertilizers provide extra phosphorus alongside a balanced ratio of nitrogen and potassium.

Do watermelons need deep soil?

If grown in the best soil for watermelons, these plants can reach immense sizes when fully mature. Despite their enormity above ground, they don’t have especially deep roots. 

Watermelon roots extend into the ground a bit less than a foot, where they create a mound. This mound is a tangle of roots that store excess water and nutrients, providing the watermelon plant with a steady food supply.

When planting watermelons in containers, you should select a container that is at least 18 inches deep. This will provide ample space for watermelon roots to grow and develop without overcrowding. Be mindful that melon roots are sensitive to excess moisture, even with the best soil for growing watermelons in containers. You’ll want to ensure the container has adequate drainage to prevent root rot.

How often should watermelon be watered?

The best soil for watermelon plants is always moist without being soggy. In most circumstances, melons should get about two inches of water each week. This can vary greatly depending on temperature, airflow, and other factors.

To determine if your plants need an extra drink of water, you can do a finger test. Simply dip your finger into the earth about two inches deep. When you withdraw your finger, little crumbles of dirt should cling to your skin. This means that the soil is well hydrated.

If your finger comes back clean, then you’ll want to give your plant some water. If the mud on your finger is thick, then the soil is oversaturated and needs to dry out. Even the best soil for watermelon plants can become an enemy if it’s too wet!

The Best Soil for Growing Watermelons

Creating the perfect environment for watermelon plants to thrive doesn’t need to be tricky. You can mix the best soil for watermelon growth without breaking the bank (or your back!) Once you have a loamy and warm plot, it’s time to plant your watermelon seeds and watch them grow in the best soil for growing watermelons you can make.

Want to learn more about this iconic summer fruit? Then visit our watermelon plants page to learn more about watermelon planting, growing, cooking, and more!

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