Germination & Vining Problems in a Pumpkin Garden

Pumpkins (Cucurbita spp.) are warm-season annuals that need up to 100 frost-free days to thrive and produce fruits. They need space for the large-leaved, rambling vines to grow, regular feeding and watering throughout the growing season and attention to the growing fruits to keep them blemish free. Pumpkin plants reward you with large yellow or orange flowers in summer and big leather-skinned fruits by October.

Pumpkins are warm-season plants. They need warm soil for seeds to germinate or seedlings to thrive and frost-free temperatures for newly sprouted plants to survive. Wait until the ground has thoroughly warmed in spring and the spring frost date has passed before planting pumpkin seeds or seedlings in the garden. Pumpkin seeds do not germinate in cold soil. If your frost-free growing season is less than 75 days, start pumpkin seeds inside about a month before you can safely transplant them outside.

Pumpkin seeds and seedlings are large. Seedlings and growing plants need a lot of room to grow well. Do not plant bunches of seeds close together, because they crowd one another out and grow stunted without enough space. If planting seeds directly in the garden in spring, plant only three or four seeds at least 2 inches apart in mounds. If planting in containers in early spring, plant one seed per pot.

Pumpkin vines are large, growing up to 1 inch thick and rambling 30 feet or more, anchoring themselves with curly tendrils to anything that is in their path. Avoid damaging vines with lawnmowers or by stepping on them, because broken vines are susceptible to disease. Broken vines also interrupt the flow of moisture and nutrients to the growing fruits and result in lost crops.

Squash bugs, squash vine borers and cucumber beetles cause problems with growing pumpkin vines. Squash bugs are small, brown crawling insects that suck the sap out of vines, causing wilted leaves and introducing yellow vine decline disease that kills the plants. Squash vine borers are larvae of moths that lay their eggs on pumpkin leaves. The larvae tunnel into the thick vines and eat the green flesh inside, leaving a substance that looks like sawdust at the holes where they enter. Control these by slitting the vine where the "sawdust" is observed, removing the larvae and then burying the part of the vine you cut into. Cucumber beetles are spotted beetles that spread powdery mildew that affects and kills pumpkin leaves, eventually killing the whole plant. Spraying weekly with natural insecticides such as insecticidal soap or Bacillus thuringiensis var. kurstaki when plants sprout and throughout the growing season controls these pests.