The best to time harvest butternut squash depend upon where you are growing your crop. Butternut squash can be grown in the USA, Australia, New Zealand and South Africa, to name just a few countries. This advice assumes your crop is growing in the USA.
Butternut squash can be planted at any time during the warmer seasons, but is it important that this must only be done once any chance of damaging frost has passed. The squash requires three to four months to grow, depending on the variety. If you wish for your squash to be ready for Halloween, then June might be the best time to plant your squash, although it may take some experimentation on your part to know for certain in your part of the world.
Squash Matures After Picking
Remember that many varieties of squash require curing after picking so it is in optimum condition when it comes to selling or cooking. Cure your squash for ten days in a warm, humid storage environment, although it is debatable as to whether butternut squash is improved by curing. Cured or not, the butternut squash can be stored in a cooler environment for up to three months. Here's a short film with a few tips on growing butternut squash: