If you don't have room to grow butternut squash in an outside garden, you can grow these gourds in pots. The pots can be placed outdoors on your balcony or patio. The butternut squash will need to be transplanted once the threat of frost passes, because squash doesn't tolerate freezing conditions. Because squash vines spread out, you will only be able to plant one seedling to a pot.
Select planting containers that are at least 45 cm (18 inches) deep and 90 cm (3 feet) wide. The containers will need drainage holes in the bottom.
Fill the bottom of the container with 5 cm (2 inches) of pea gravel. This will improve drainage from the containers.
Fill the pot with potting soil. Dig a hole in the centre of the potting soil two times wider and deeper than the squash transplant container.
Remove the squash from the container if it does not reside in a peat pot. You can do this by placing the squash container on its side and gently squeeze it to loosen the soil. If the squash resides in a peat pot, you can plant it directly into the soil. The top of the peat pot will need to be at the soil level. Place the squash transplant in the hole.
Fill the hole with soil and pack firmly around the squash. Place the squash pots where they will receive direct sunlight during the day.
Water the seedlings until water begins to drain from the bottom of the pot. The butternut squash will need regular watering to keep the soil moist so it does not dry out.
Apply a water-soluble fertiliser to the squash when it begins to flower. Follow the dosage instructions on the package.
Harvest the butternut squash when the vines dry. The vines that are attached to the squash will appear brown and wilted when the squash is ready to harvest. Cut the squash at the stem, and leave 5 cm (2 inches) of the stem attached to the squash.
Buy the smallest transplants, between 5 to 10 cm (2 to 4 inches) in height, because they will develop healthier root systems in the container.