Like most squash, Guatemalan Blue squash is sensitive to frost. Sow seeds indoors 3 to 4 weeks before the expected last frost date, or sow them directly in the ground after the last frost, once the soil has warmed sufficiently (to at least 15°C).

Squash prefers rich, well-drained soil with a pH between 6.0 and 6.8. Add compost to the soil before planting.

Sow seeds about 2.5 cm deep. Plant them in groups of 3 to 4 seeds spaced about 90 to 120 cm apart, with at least 2 to 2.5 metres between rows. Once the seedlings are about 10 cm tall, thin them to keep only the 2 strongest plants in each group.

Squash needs regular watering, especially while the fruit is forming. Keep the soil evenly moist without waterlogging it to prevent root and fruit rot.

Apply a layer of organic mulch around the squash plants to help retain soil moisture, regulate temperature, and reduce weed growth.

Give squash a balanced organic fertilizer at planting. Once the fruit begins to form, add an organic fertilizer rich in potassium every 2 to 4 weeks to support fruit development.

Guatemalan Blue squash is generally ready to harvest 100 to 110 days after planting, when its colour is even, the skin is hard, and the stem is dry and woody. Use pruning shears to cut the stem, leaving 5 to 10 cm attached.