Organic Watermelon

A long growing season (a minimum of 3 months of warm weather) is required to mature and establish sweet watermelons. In other words summer locations, a warm indoor start can count towards the long-season requirements. If you reside in the North, beginning your watermelon seeds inside your home 2-4 weeks prior to your last frost date will enable you to benefit from any warm, bright days outdoors and still have the ability to bring them in the evening or on cooler days. Planting too early will trigger the plants to establish tendrils or more than four leaves which might cause your plants to have trouble setting roots once they are transplanted to the garden. In the warmer southern environments, watermelons can be direct-seeded in the garden when soil temperatures have actually reached a stable 75-80F.

Where to Plant Watermelon

The secret to growing a successful watermelon crop is to offer as many warm, warm days as possible for the growing plants and secure them from cold temperatures. The more exposure heat the vines receive, the more fruit your plants will produce in the summer season.

Watermelons require full sun and a lot of heat. Offer your watermelons the sunniest area readily available with good air circulation. This will assist the plants dry quickly after a rain to prevent diseases.

Preparing the Soil for Watermelon

Watermelons prefer well-drained, sandy loam soils with a pH level in between 6.0 and 6.5. Soils with a pH less than 6.0 will produce plants with yellow foliage and less best flowers. Good drainage is important for preventing illness in your melon plants. If your soil doesn’t drain water well, mix a generous quantity of raw material into the soil prior to planting. We suggest mounding your soil into hills. Raised hills enhance drain and assists keep the soil temperatures up. If you water with soaker hose pipes, mounding up a row (rather than hills) will make watering much easier.

Mix in a shovel full of well-aged manure where you plan each hill. This is particularly crucial if a spring crop has actually already been planted in this area and taken nutrients from the soil. Mound your manure changed soil into hills about 12″ high and 2′ -3′ wide. Area each hill 4′ -6′ apart, depending on how much area your range needs. Adding 2-3″ of aged manure or garden compost before planting your melons will give the plants a nutrient boost and improve your soil’s structure.

As much as I’m not a fan of plastic, it’s nearly a requirement when attempting to grow watermelons in a much shorter growing season. This is something you will require to choose on your own. Watermelons develop sugar and develop sweet taste in their final days of development so providing the needed heat is critical for growing an excellent watermelon crop.

Covering your planting area with plastic a couple weeks prior to transplanting will warm the soil faster. Depending upon the weather condition, this can enable you to transplant your seedlings outdoors approximately 7 to 10 days earlier than without the use of plastic.

If plastic is left throughout the growing season, it will decrease ground rot in your fruit (fruits decaying from sitting on soil). Clear plastic mulch will heat up the soil up 4-5 degrees warmer however black plastic will prevent weed development.

Ventilation holes must be made in your plastic mulch to enable oxygen into the soil. If your plastic doesn’t have pre-made ventilation holes and it is still on the roll, you can use a 3/4″ drill and drill your own holes through the layers at an 8″ x8″ spacing.

Selecting the Right Seeds

When choosing a watermelon range, think about how much space the plant needs to spread out. If you have a minimal growing location, pick a bush type that is more compact. Some heirloom or more energetic varieties can take up 100 square feet per plant and just produce 2-3 fruits.

Seeds and Germination

Watermelon seeds sprout optimally in between 70 and 90 degrees F. At these temperatures, seeds will germinate within 5-10 days. At temperatures listed below 60F, germination will not occur.

Beginning Inside Your Home

Watermelons do not endure frost or preserve appropriate development at temperatures listed below 60F. In areas with brief summertime, seeds must be begun inside and later on transplanted outdoors; be very careful not to disturb the roots. Watermelon plants do not grow well if their roots are disturbed, even when young seedlings.

Plant your seeds in loose potting soil (not seed germinating mix as it includes no nutrients for the developing seedling).

Plant 2 seeds 1/2″ deep per 4″ individual pot (I plant 2 seeds in case one seed does not germinate, and as the seeds grow older I might include 1 or 2 more simply to be sure I get one excellent plant). Watermelon seeds remain usable for 5 years after your initial purchase.

Keep planted seeds in a warm, sunny area (such as a south-facing window) where soil temperature levels maintain between 70F-95F. Use bottom heat if essential to maintain around 75F soil temperature level. When your seedlings are 2″ tall, thin each pot to the one greatest plant by cutting the other seedlings off at soil level.

Transplanting to Outdoors

Starting your seeds inside can extend your melon growing season 2 to 4 weeks but melons are particularly sensitive to transplanting. If the roots are disturbed, your plants growth will be stunted.

Vines might not set fruit if they’re chilled when seedlings so make sure the soil temperature levels stay steady at all times and the garden soil has warmed to 70-80F before transplanting outside. Planting in cooler soil will likewise increase the possibility of soil-borne root diseases establishing.

To prevent disrupting the roots, 4″ usage peat pots or other biodegradable planting pots instead of plastic seedling pots. Peat pots will break down rapidly and allow you to plant the pot directly in the garden bed when you transplant the seedlings.

Carefully tear or cut out the bottom of the peat pot prior to planting in the ground to allow the roots to spread out more quickly. Be really careful not to cut the roots. If the roots are too dense (root bound) at the bottom, do not cut the bottom out as you may harm the roots.

Transplants need to have 2-3 fully grown leaves and a well-developed root system when they are moved into the garden. Planting seedlings that have developed 4 or more leaves may have difficulty setting roots as soon as transplanted to the garden.

If you covered your soil with plastic to help raise the soil temperature level, you can get rid of the plastic before planting or leave the plastic down to continue locking in the heat. Cut slits in the plastic every 4 to 6 feet and plant seedlings through the slits.

If you select to leave the plastic down, make certain to slow well. Plastic that is not anchored well can blow off throughout a windy day, breaking your plants while doing so. If growing watermelon in rows, space seedlings 18 to 24 inches apart within the row. Area rows 5 to 6 feet apart. In much shorter season areas, only plant one plant per hill so it will not contend for nutrients with other vines. In warmer climates, 2-3 plants can be planted per hill.

Crop Covers

To safeguard your young plants from wind damage, which can slow down development and lower the quantity of fruit the vine will set, place hot caps, plastic tunnels, or a row cover over the plants the first 2-3 weeks up until the plants have a possibility to better establish themselves.

Making use of among these coverings will likewise safeguard your plants from cooler air temperatures and early insect bugs. Eliminate the covering within 2-3 weeks to prevent high temperature plant injury and to enable bees and other pollinators simple access to the flowers.

Direct planting (planting seeds straight into garden bed).

Follow the above instructions for preparing your soil and forming hills. When your hills are formed and modified with well-aged manure or compost, plant the seeds 1/2″ – 1″ deep, sowing six seeds per hill.

When your watermelon plants have actually reached 2″ tall, thin seedlings to 2-3 plants per hill by leaving the healthiest and most vigorous seedlings and cutting the remaining plants off at soil level.

If planting in rows, plant 2 to 3 seeds together (a couple inches apart from each other) every 18 to 24 inches within the row. As soon as the seedlings are 2″ tall, thin to the best plant per group by cutting the staying plants off at soil level.

Don’t pull weeds up by hand. Hand-pulling might disrupt the root systems of the other plants and pull them out of the soil.


Using 2-3″ of mulch around the plant will save soil wetness and lower weed growth. Organic mulches like wood chips or straw can likewise be utilized when growing watermelons, however do not apply organic mulches up until soils are warmer than 75ºF. Applying organic mulches too early keeps the soil cool, resulting in slow growth and shallow rooting.


The roots of melons grow near the surface of the soil, so it is essential not to cultivate too deeply or too near to the plants. Cultivate simply deeply sufficient to cut the weeds off below the surface of the soil. Continue cultivating until the vines begin to spread in between the rows. Then pull large weeds by hand.


Routine deep watering is specifically crucial during the very first 3 to 4 weeks that growing watermelon vines are growing in your garden. Leak watering or soaker tubs are the best way to provide watermelons a constant supply of moisture. Water deeply and occasionally (1-2 times per week); provide an overall of 1-2 inches of water weekly.

Cut down on the water once the plants have begun to set fruit; over-watering will water down the melon’s sugars, causing it to be less tasty and lose sweetness. Excessive water could also worry the plant and trigger less fruit to establish. There is extremely little benefit in a light watering that only wets the soil’s surface. Deep, irregular, but constant watering is exceptionally important especially in the last 2 weeks of development. Extreme watering at this phase can cause the fruit to divide.

Buddy Planting and Rotation Considerations.

Watermelon does not allow much space for buddies, and does best when it can sprawl out freely without competing for nutrients with other plants.

You can try planting Marigolds or Nasturtiums in the area which prevent beetles, or Oregano which offers general bug security however it is most likely the vines will smother them if planted too close. They need to be in their own pot or raised bed, out of the reach of the intruding vines.

Due to the fact that watermelons remain in a different class than muskmelons (cantaloupe) and both require the exact same care, they’re excellent companions. Watermelons and muskmelons share the same nutrient requirements and have the same watering needs; and due to the fact that they are in a various classes, their seeds will not cross-pollinate.

When to Harvest.

Ripe watermelon does not slip from the vine when it is ripe, so it takes a little bit more know-how to tell when a watermelon is ready to pick.

Use this mix of signs to check for ripeness:.

Tendrils near the fruit stem have actually become brown and dry;.

The fruit surface is rough to the touch and the fruit color is dull;.

The bottom of the watermelon (where it rests on the soil) has actually altered from a light green to a yellow-colored color;.

Look for ‘black sap areas’. These are triggered by bees extracting the juice from the melon. If there are a number of beads of hard black sugars, you understand you’ve got a sweet melon.

Preventative and Natural solutions to Common Insects and Problems.

The use of row covers will assist prevent infestations of many pests (see Row Covers, Hot Caps, & Plastic Tunnels).

Striped and Spotted Cucumber Beetles.

These pests spread bacterial wilt throughout your crop when they feed; they tend to assault around the time the plants start flowering. Note: Male flowers will appear initially, at leaf joints on the main stem and female flowers will appear. About one week later, female flowers will develop off of secondary side-shoots.

Your finest defense versus these insects is to cover your plants with row covers up until flowering. The covers should be eliminated when the female flowers appear so that the bees can access the plants for pollination.

An extreme problem can be managed with pyrethrins; the pyrethrins are a pair of natural organic compounds that have powerful insecticidal activity.


Melon Aphids.

Aphids are tiny pear-shaped pests with long antennae that draw sap from the plant, causing the leaves to become distorted and drop.

A strong spray of water can frequently knock the insects off your plants. Crushing a number of cloves of garlic into a spray bottle filled with water and spraying mixture on the plants can frequently deter these bugs. Insecticidal soap, pyrethrins, and neem oil are also effective natural insecticides for heavy problems.

Squash Vine Borers.

Squash vine borers appear like 1″ long white caterpillars. They bore through the stem of the plant and may be unnoticeable to the gardener until the vine begins to wilt.

In April (in the South) and in late June or early July (in the North), keep a lookout for an orange and black wasp-like moth. This is an adult borer which lays eggs at the base of the stem during this time. The small orange and red eggs are laid simply below the surface of the soil. Get rid of and crush any eggs you can find.

Once the season progresses, watch for entry holes at the base of the stems. If the hole is surrounded by a yellow dropping that resembles sawdust, cut a slit in the stem and remove any larvae. An injection of Bt can likewise be utilized (Bacillus thuringiensis, or Bt, is a soil-dwelling bacterium, frequently used as a natural option to chemical pesticides).

Ecological Factors.

Vine crops that have recently been transplanted or that have actually been directly-seeded outdoors and recently sprouted have actually been understood to all of a sudden wilt and pass away. Usually this occurs when you have a stretch of 4 or more days of rainy, or overcast weather condition with no defense over your plants to keep heat. If soil temperature drops down listed below 60F, the plant roots stop taking in water from the soil.

When the sun does reappear, water evaporates from the leaves faster than the roots soak up water, which leads to abrupt wilting and death. To prevent this from occurring, keep your plants secured when cool wet weather is forecasted with making use of row covers or hot caps. In humid climates, watering the roots straight rather than soaking the leaves helps prevent lots of typical foliar diseases.


Many diseases can be prevented by following these guidelines:.

When growing watermelon choose varieties resistant to common illness such as grainy mildew. Wait up until the soil has actually warmed to a minimum of 70F before planting seeds or transplants and keep soil temperature levels regularly warm throughout the whole plant cycle. Keep seeds and seedling beds moist but not water logged.

If starting inside, plant seeds in 4″ pots or bigger to minimize root disturbance and allow more space for roots to establish effectively. Transplant seedlings once they have 2-3 real leaves. Avoid over-applying Nitrogen (such as animal manure). Excessive nitrogen, especially throughout the fruit set, can encourage “hollow heart” and boring flavor. Offer great air movement around plants by keeping weeds under control and planting with appropriate spacing.

Grainy mildew.

Powdery mildew, a fungus, can cause leaves to prematurely die, and minimize yield and fruit quality. Damage can include brown spots, tattered holes in leaves, sunken brown lesions on vines, and rotted fruit. Grainy mildew infections are generally brought on by warm, damp conditions (68-81F), or the plant perspiring too long from rain or overhead watering.

In warm, dry conditions, brand-new spores are produced in leaf areas and can easily spread illness by being blown by the wind and infecting other leaves. To prevent these diseases do not grow melons in an area where any member of the squash household has actually been grown for 3 years or more. Lower wetness on leaves by offering plants with correct area, controlling weeds, and utilizing drip irrigation or a soaker hose pipe instead of sprinkler irrigation. Apply a natural fungicide when a single spot of powdery mildew is identified. Sulfur products can be applied to both the upper and lower surfaces of the leaves. Remove significantly contaminated plants and any debris from the garden.

Plant disease resistant ranges whenever available. Resistance is virus specific and it is needed to first identify which mosaic virus is common in your location. A credible seed company in your part of the nation will have this information. If not, ask your county extension.

Purchase tidy seed from a trusted provider. If conserving seeds, do not gather seed from contaminated plants. Control weeds within and around the planting area. Specifically seasonal weeds that can carry the infection from one season to the next. Control aphids and cucumber beetles early on to keep populations low. If disease appears in a couple of plants, bury or dispose of these plants to prevent more spread of the illness. Wash hands and tools after working with contaminated plants.


Watermelons will keep in the fridge for as much as one week, but not only will flavor and sweetness reduce, so will nutrition levels. The best way to store a watermelon is at a room temperature level of 50-60 °, such as a basement. Watermelons will last approximately 2-3 weeks and retain their flavor, sweet taste and nutrition. Melon flesh can be frozen (think watermelon healthy smoothie) and rinds can be marinated.