Harvesting one ton removes an average of 4 pounds N, 1.4 to 2 pounds P2O5, and 5 to 9 pounds K2O from the soil. As with most fruiting plants, N applied must be adequate to develop a vigorous canopy, but not so high that vegetative growth is stimulated during the period of fruit development. If this happens, leaves and fruit compete for carbohydrates and fruit yield and sugar content may be reduced. Adequate P may be available in previously cropped southern soils, but in alkaline western soils and some other soils, P2O5 additions may be necessary to stimulate seedling growth, and maximize fruit size and sugar content. Considerable boron is required and may need to be applied as a foliar spray.
Muskmelons are very susceptible to fertilizer burn.
Additional N and K fertilizer applications are usually provided at last cultivation. See Soil Management for a discussion of organic sources of these nutrients. 90 degrees F is optimal. In North Carolina, muskmelon rows are usually spaced 5 to 6 feet apart with the final stand of plants 18 to 24 inches apart in the row. Two thinnings are often required because muskmelon seedlings are vulnerable to pathogens and birds until establishment, and a single thinning could result in gaps in the final stand.