Growing watermelon, cantaloupe
Many of us who garden in western Montana have discovered that we do not have the ideal climate for melons. These subtropical plants do well at lower elevations on the west side of Lake County, but for the rest of us ripening them can be quite a challenge.
With a little care and preparation, melons can be grown anywhere in our area as long as they receive full sun. Both cantaloupe and watermelon prefer warm, rich, sandy soil, full sun and a location protected from wind. Siting is important for success; good airflow is helpful to prevent powdery mildew. Protection from deer is essential — a good 6- or 7-foot-high fence is the best solution I have found. Your soil should be carefully prepared for best results, so testing with a good soil test kit is always a good idea. Watermelons need a slightly more acidic pH (5.5 to 6.5) than cantaloupes, which prefer a pH of 6.5 or more. Pine needles, coffee grounds, used black tea leaves and sulfur will lower pH; wood ashes, kelp meal and lime will raise pH.
If your soil is heavy, add compost, manure and sharp sand to the existing soil. Melons of both types grow fastest in warm to hot conditions. Planting in raised beds increases soil temperature by heating up quickly in sunshine and elevating plants above cold air currents. Planting inside large rubber tires is one solution, and raised beds of untreated lumber are excellent.
One tried and true method to heat your soil is to create a hotbed with fresh manure placed 18 inches or more below the planting level. The manure heats up as it begins to compost, releasing heat night and day. A hotbed should be active for about a month and will give melons a great start in our cold springtime weather. In the 1700s and 1800s French market gardeners perfected this method of growing melons and produced very high yields.
Cloching, or covering your plants with cold frames, is a time-tested method of growing melons because it keeps air and soil temperatures high at night. (Be sure to admit air during the day to cold frames and cover them with mats if frost threatens.) Open-ended plastic tunnels are excellent cloches for melons as air can travel through and ventilate the plants without overheating.
A few early-maturing heirloom cantaloupes are: ‘Jenny Lind’ (75 days) from 1846, ‘Prescott Fond Blanc’ (70 days) from the 1860s, and ‘Ananas D’Amerique a Chair Vert’ (80 days) from the 1700s.
Some early-maturing heirloom watermelons are: ‘Hopi Yellow’ (75 days) a yellow melon from the Hopi tribe; ‘Cream of Saskatchewan’ (80 days) a white melon from the 1860s; and ‘Blacktail Mountain’ (80 days) from the 1930s.