How to Grow Melons
When selecting your site, look for the spot in your garden that receives the most sun and the least wind. It may take a couple years of trial and error to determine this location, but if you want to grow melons successfully it is worth experimenting to find the "sweet spot" in your garden.
Melons like well drained, loose soils that hold moisture well. The best way to provide these characteristics is with the additional of well-rotted compost just prior to planting.
Melons will not grow well if the soil is cool, so you must wait until late spring to plant your seedlings. Daytime temperatures should be steadily warm and the weather conditions stable. Do not disturb the roots when you transplant. Move the plant carefully from pot to soil, firm the surrounding soil, and water in well with some fish emulsion mixed in to the water. Melons are traditionally planted in hills (the contents of your transplant pot equals a hill), 3-5' apart. Researchers have learned, though, that 18" between both plants and rows may result in higher yields.
Whatever the spacing, the use of black plastic mulch around melon plants dramatically improves results. Black plastic warms the soil, aids in moisture retention, and suppresses weeds. A 36" wide roll down the row works well. Lay the plastic down carefully over your seedlings and cut an X using a razor to allow the seedling to poke through the plastic. Pin down the edges of the plastic using soil staples. Black plastic reduces the necessity to weed around your plants, making it less likely that you will disturb the vines. Beware, melon vines are easily damaged when moved.
Maintain steady soil moisture while your plants are growing. Pay particular attention to their water needs when the fruits are in their phase from 3" in diameter to maturity. There is evidence that irrigation in this final period of growth produces larger fruits and therefore higher yields. There is no indication it affects the sugar content and therefore the flavor of the fruit.
One of the primary benefits of growing melons in your backyard is that you can pick the fruit when it is perfectly ripe, unlike truck farmers who must harvest early to get their as yet unripe fruit to market. The sugar content of the fruit builds in the final days before harvest, and for the best tasting, sweetest fruit you must wait until the final moment to pick.
Knowing when to harvest your fruits takes experience. Holding the fruit to your ear and thumping is not a valid test for ripeness. Muskmelon varieties such as Hearts of Gold will slip, or separate, from the vine when they are ripe. Push lightly on the stem if you think it is ready, but if the stem resists wait a while longer. Inodorus melons (Crane and Honeydew) do not slip. Look for subtle changes in color called "warming", and yellowing of the leaf where the stem meets the fruit before you cut the melon from the vine. Use a knife or scissors to perform the procedure; do not pull. True cantaloupes (Charentais and Noir des Carmes) reveal their ripeness by changes in color and cracking where the stem joins the fruit. Do not be alarmed by cracks, they mean your melon is ready to eat! Arava (Reticulata) melons reveal their ripeness by changing color from green to yellow. Cut the stems to harvest cleanly.
Once harvested your may keep your fruit refrigerated for about a week in the refrigerator, but the very best approach of all is to harvest and eat the same day. Delicious!