How to Manage Pests

Cultural Tips for Growing Watermelon

In This Guide

Site selection

Plant your garden in a convenient location, where you can check it frequently. Choose an area near an abundant supply of water so you can water as needed easily. Vegetables do best if they receive full sunlight (at least 4 to 6 hours a day). Plant them in a well-exposed area in the garden, where they are not shaded by trees, fences, or walls. Try to plant away from areas that will be watered by lawn sprinklers.

Whenever possible, select a location that is not heavily infested with weeds, especially weeds such as field bindweed, nutsedge, and Bermudagrass that can be hard to control with hand weeding. Also avoid areas that have had previous disease problems.

Try to plant on level ground. Level ground is easier to work on than sloping ground. Vegetables will do well on a wide range of soils; they do best in well-drained soils. If your soil forms a clump when squeezed, then it is too wet; if the soil crumbles easily, it is a good soil to use. Damp soil surfaces encourage snails, slugs, sowbugs, and root diseases; fruit decay and leaf spot diseases may also increase. Soil amendments can make clay and sandy soils easier to work with, and correct soil preparation can improve poor soil.

Adding organic matter (compost, peat moss, manure, sawdust, ground bark) makes clay and sandy soils easier to work with. The soil should be kept at a pH level of 6.0 to 6.5. Lime or gypsum can be added to soils low in calcium.

Soil recommendation

Well-drained fertile soils; choose non-saline sandy loam or silt loam.

Soil improvement

Any type of soil can be improved with soil amendments. Heavy clay or sandy soils can be improved by adding organic material such as compost, manure, or leaf mold. Texture is an important consideration when choosing an amendment. An amendment that is granular and fine grained is important for container mixes. For gardens, a more coarse-grained amendment can improve drainage and aeration. Work amendments into soil by rototilling, raking, or double-digging.

Soil preparation

The preparation of your soil is just as important as adding fertilizer and soil amendments. Before working the soil, make sure it is moist but not thoroughly wet.

1. Use a shovel, rototiller, metal bow rake, or all of them together to loosen the top 1 to 2 inches of soil. Rake the area to remove weeds and old crop debris. Be sure to dig out roots.
2. Irrigate the plot deeply to encourage the germination of weed seeds.
3. In a week or two, after a substantial number of weeds have germinated, work the area again to kill the weed seedlings. Be sure to break up the clods in the soil, as seeds planted in cloddy soil will germinate poorly and won't live long because the soil dries too quickly.
4. Form soil into beds if desired, and plant while soil is still wet.

Time to plant

Watermelon are warm-season crops that can be grown over a wide climatic region. However, they do not tolerate frost. They can be productively grown between the frost-free periods, as they are short-season crops.

Planting Watermelon

Watermelon can be seeded directly or transplanted into the garden. It is ideal to plant on raised beds made by adding large amounts of soil amendments so that a bed is established above the previous level of soil. If seeding, plant more seeds than necessary so as to make up for any losses. Plant seeds in rows 4 to 6 feet apart depending on which crop you are planting. Push them into the soil 1 to 1.5 inch deep. Fill these holes by scratching the surface, firm the soil lightly, and cover with a thin mulch of organic material in order to hold soil moisture. Keep moist during the germination period. When the plants are about 3 inches high, thin plants.

For transplants, use young plants with 4 to 6 true leaves, wider than tall, stocky, succulent, and slightly hardened to outdoor conditions. Make sure the planting site is level. Spread and mix organic amendments and a good granular phosphorus fertilizer over the area. Mark where you want each plant and make the hole deep enough to bury the stem as far as the first leaf. Place the plant deep into the hole. Press the soil firmly around the plant and water thoroughly to remove any air pockets. If transplanting in the summer, shade the plants in the middle of the day for the first week or use floating row cover.

Fertilizing

Most vegetables require fertilizer for growth. Organic materials, such as manures and compost, and inorganic materials, such as chemicals, can be used to fertilize plants. Using both types of materials usually provides the best growth. Manures and compost can be used to increase soil fertility. They are usually applied at 1 pound per 4 or 5 square feet. These materials should be worked into the soil several weeks before planting in order to allow it to decompose. Manure that contains straw, sawdust, or similar materials should be applied with a commercial nitrogen fertilizer. Generally, if the soil has been properly amended with compost or manures or other organic materials, the only nutrient needed is nitrogen, if anything. Some commercial nitrogen fertilizers available are urea, ammonium sulfate, calcium nitrate, and ammonium nitrate. Apply these fertilizers at rates of 0.5 to 1 pound of nitrogen per 100 feet of row.

If manure and other organic material has not been used, apply fertilizer that contains both nitrogen and phosphorus before planting. All commercial fertilizers are labeled by the percentages of N-P-K; nitrogen (N), phosphorus (P), and potassium (K). Some common mixed fertilizers are 5-10-5, 5-10-10, 8-16-16, and 12-12-12. Apply these fertilizers at rates of 1 - 2 pounds per 100 feet of row. After plants are 3 to 4 inches tall, sidedress nitrogen in narrow bands or furrows and water thoroughly after application, or apply through the drip system. Consider light but frequent applications of nitrogen fertilizer every 3 to 4 weeks. Avoid letting the fertilizer come into contact with the plant stems to avoid burning.

Application tips

Inorganic fertilizers can be sidedressed. Manures are more difficult to use as a side dressing and must be tilled into the soil.

Banding: Make a small groove 1 or 2 inches deep on both shoulders of the bed, 4 to 6 inches

Watering Watermelon

Watermelon may be grown under drip or furrow irrigation. Avoid wetting the foliage or fruit with overhead watering. When direct seeding, the beds should be irrigated until completely wet. After the seedlings emerge, water when moisture is being depleted from the soil. Apply water to 1-foot depth to insure deeper rooting. If plants are stressed for water when they start to set fruit, the melons will be small and rot will increase. If plants get too much water, it may cause fruit to split.

Harvesting and Storing Watermelon

Watermelons should be harvested as soon as they reach maturity. Leaving the fruit on the plant too long may result in split melons or fruit decay. It also results in fewer flowers developing later on and a yield reduction. When harvesting be careful to not damage the fruit or stems. Twist off the fruit, instead of cutting it, to avoid spreading disease.

Storage for watermelon is short. They may be stored for a few weeks under refrigeration. Watermelons lose color and crispness if stored too long. However, some melon flavor improves because some acidity may be lost in slightly immature melons.

Harvesting and storage tips

To test watermelons for ripeness (about 90 days after planting), rap the side of the fruit with your knuckles. A light or metallic sound means that the fruit is still green; a dull sound means it is ripe. This test is most reliable in the early morning.