The most successful growers are very particular in regard to the character of the seed which they use. Breeding plats are sometimes maintained, because it is important to take the plants as well as the individual melons into consideration. It is desirable to discard the seeds at the stem and the blossom ends of the melon, because they are not so mature nor so well developed. The seed is often kept four or five years, so that it is unnecessary to grow and save seed annually.
Watermelon seed is usually planted in the open ground where the crop is to mature. In northern districts, however, the plants are sometimes started under glass as described for cucumbers (436) and for muskmelons (512).
The soil must be well supplied with humus, although an excessive amount may cause too much vine growth at the sacrifice of fruit. The methods of soil preparation are practically the same as for muskmelons (513).
See notes (514) on fertilizing muskmelons.
See notes (515) on planting muskmelons. Where soil is rather poor, watermelons may be planted in hills, 8 × 8 feet apart; but the more common distance is 10 × 10 feet, while in rich soils the hills are often 12 × 12 feet. The seeds are sometimes planted in drills as explained for muskmelons (515), but more space is allowed between the plants in the row.
See notes (516) on cultivating muskmelons. Always stir the soil about the plants in the hills after hard rains, which may incrust the surface.
It is exceedingly important that every melon be sent to market at the proper stage of ripening. If it is underripe, quality will be sacrificed, and if overripe it will not carry well on wagons or cars, and the quality will also be inferior.
Experience counts for more than anything else in enabling one to determine the proper time to pick melons. Many people who live in melon districts and have helped to harvest the crop for a number of years can invariably tell when a melon is ripe, but they are unable to explain how they know. The sound emitted when the melons are "thumped" is the most reliable means of determining the state of ripeness. Regarding this matter the Georgia Station (Ga. Sta. Bul. 38, p. 76) calls attention to the advice of the old negro "mammy." in the ballad, when she berated her grandson for stealing a green melon: "Be shore, when you thumps 'em dey alius soun' 'plunk.'" The Arizona Station (Circular 44) writes: "Most varieties give forth a distinctly different sound when ripe and when green. The greener the melon, the sharper and more metallic is the ring that it gives forth if snapped with the finger. As the melon matures and becomes less solid, it gives forth a somewhat hollow and distinctly muffled ring. The riper the melon, the more nearly the sound given will be like that produced when the palm of the hand is snapped with the finger. Some varieties will be ready for market, while the melons still give forth a somewhat metallic sound, while others must be left on the vines until the sound is quite a 'dead' one. These are matters that can soon be learned by experience. The writer knows by long experience that if proper precaution is taken and a doubtful melon cut occasionally, there is little excuse for ever putting a green melon upon the market."
The test of the tendril (the melon being considered ripe when the tendril is dead) is unreliable. When the underside of the melon "begins to turn yellowish and becomes rough, pimply or warty, with the surface sufficiently hard to resist the fingernail when scratched, it is usually a fair sign of ripeness."
Watermelons are shipped in bulk in box cars, which are bedded with straw. They are usually loaded four deep in the cars and the freight paid according to weight. The following table shows the number of melons of different sizes that can be loaded on a car (Ind. Sta. Bul. 123, p. 17) :
Car 34 feet long loaded 4 deep contains:
Averaging about (lbs.)
Car 36 feet long loaded 4 deep contains:
See notes on muskmelons (519, 520).