Butternut squash is a tan squash with a bright orange flesh. It tastes tastes like autumn. It is sweet and nutty much like pumpkin but sweeter and less stringy. Caramelizing it brings out the sweetest, richest flavor. Caramelizing is cooking it until it has a nice golden crust on it, bring out the natural sugars and flavors. I love it roasted with garlic and onion. It also makes a wonderful winter soup.
It is a winter squash, which means it doesn’t fully mature until fall. In our area, that’s around the time of frost. So I start them indoors to give them a head start. My favorite variety is the Waltham Butternut.
Planting– Choose a site in full sun. Well drained, neutral, fertile soil.
Butternut squash is a long, vining plant, so they will need room to sprawl. The planting area doesn’t need to be large though if you grow UP. Vertical gardening is a great way to make the most use of your limited space. The vines have tendrils that grab onto it’s supports. It also keeps the fruits off of the soil, reducing the risk of rot from sitting on the wet soil.
While you can grow these in containers, I’ve found they don’t get very big, so I would say the garden is best.
I usually start my seed indoors to give it a head start, about 4-6 weeks before the last frost. Then plant outside after danger of frost is past. If started indoors, they will need to be harden off first. This means to put them out a little longer each day so they can acclimate to the outdoor climate and the direct sun. Usually takes about a week.
Space 12-18″ apart.
Growing– The squash need regular watering for good growth. They have large leaves so they loose water quickly. About an inch of rain or water per week. Remember, when you water, water the feet not the head. It is also best to water in the morning to reduce the risk of mildew on the leaves.
The fruit develops just behind the female flower. Each plant has male and female flowers.
On the left above is a female flower. See the tiny potential squash behind the flower bud? On the right is the male flower. Nothing behind it but stem. If the female isn’t pollinated, the little squash will wither up and fall off. It have noticed a reduction in the pollinated flowers over the last few years. Perhaps from the reduction of bees? Hand pollination is always an option.
Fertilizer– Squash are big eaters. Use a general organic fertilizer.
Hardiness– Winter squash do not withstand frost or freezing temps.
Pests and Diseases– Powdery mildew is probably the biggest problem. It usually shows up in August when it gets very humid.
Squash bugs are also pretty annoying. They suck your plant dead. You will notice clusters of yellow eggs under the leaves. Cut it off and toss it before they hatch.
Squash vine borers are also a problem, but I find they prefer zucchini plants over butternut squash. You will recognize this by a sudden wilt of the plant and saw dust looking mess as the base of the vine near the roots.
There are organic sprays available for all these problems.
Harvesting– Leave your butternut on the vine as long as possible. Even past the leaves dying back. The butternut should be a nice dark buff color with the green lines gone. The skin should also resist when you press with your fingernail. The stem should be brown and dried up. Those are really the only ways to tell if it is ready.
However, if the squash is damaged you should harvest it and cook it before it goes bad.
Once frost is upon you it is best to take them off the vine or cover them.
If you want the butternut to last several weeks or months, you will need to cure it. That’s really just letting it sit in a warm, dry, shady spot for a few days. If cured properly, they can last into March or April. Our last one is usually eaten around March, depending on how many I am able to harvest.
Updated June 2018