Proper fertilization, seed spacing and the use of plastic mulch and floating row covers are important to producing big pumpkins in your garden.
Mulches help to warm the soil, control weed growth and maintain good soil moisture levels. Floating row covers help to protect the plants early on from wind and cool temperatures — assuring quicker growth.
Always apply lime and fertilizers based on soil test recommendations. Giant pumpkin vines require approximately 2 pounds nitrogen (N), 3 pounds phosphorous (P) and 6 pounds potash (K) per 1,000 square feet of growing space. Pumpkins also like a rich, well drained soil and will benefit greatly from the addition of organic matter (compost, manure, etc.) to the garden.