Tips for Growing Butternut Squash

 Tips for Growing Butternut Squash

    It's sweet and loaded with fiber. 

    It is incredibly versatile yet also impossibly prolific.

    It's loaded with beta-carotene and can be stored in the pantry all winter.

    Butternut squash is truly the unsung hero of the garden; it's a pantry staple for anyone who's looking for a little bit of long-term food security from their garden. It's important to know how to grow this crop correctly when you're relying on it to feed your family. 

    While butternut squash is typically very easy to grow, there are a few problems that could wipe out your harvest, or even your entire crop. That's a devastation that many first-time gardeners go through, especially when squash bugs take over quietly.

    In this guide, I'm going to step you through the process of growing butternut squash successfully, providing my tips along the way. 

Small butternut squash that was stored for 6-8 months before being cooked. This squash cured in the garden before being cut from the vine. 

Always Plant Your Squash After the Last Frost Date

    I know it's tempting to plant right before your estimated last frost date; but this is a risk that I cannot recommend. As a matter of fact, due to the sensitive nature of squash, I recommend planting it one week after your estimated last frost date.

     This will help to ensure that your plants don't get hit by an unseasonably late frost. After all, your ELFD isn't a guarantee that there won't be a frost; it's simply a date by which the risk of frost is low- not impossible. 

Squash seedling sprouting among my native clay garden soil.

Always Direct Sow Squash Seeds, if Possible

    The general consensus is that transplants will grow and fruit faster than direct sown plants. While this is typically true for slower growing plants such as many herbs, tomatoes, peppers, and perennial flowers, plants that grow from large seeds (squash, beans, sunflowers, peas, okra, etc) always seem to grow much faster when direct sown. 

    If you transplant a 4-week-old squash plant at the same time that you direct sow butternut squash seeds, you'll likely witness the seedlings surpassing the transplants in growth, vigor, and production. Seedlings don't encounter transplant shock, and there's no adjustment period. Therefore, seedlings can quickly overtake transplants that are dealing with transplant shock. Save yourself money, labor, and a trip to the store; just plant a packet of butternut squash seeds! 

Young squash plant in a freshly weeded garden

Don't Forget the Compost When Sowing Butternut Squash Seeds

    If you don't have homemade compost, that's no big deal! I personally love Black Kow, composted cow manure that comes in a yellow bag. A little goes a long way; you can either till the product into the soil for distribution throughout the plot, or you can simply amend planting holes. Typically, I only amend the planting holes with this product to reduce costs, and I use 1-3 cups per hole depending on what I'm planting. Squash plants are very heavy feeders, and you want to ensure that they have adequate nutrition throughout the growing season. 

Blemishes on a butternut squash aren't always a guarantee that the squash will go bad in storage. It's important to do periodic checks on your winter squashes in the cellar or pantry, just to keep an eye out for rot. This squash was 6-8 months of before being cooked and was in great shape. I believe the blemishes are a result of squash bug damage.

Planting Location Requirements for Butternut Squash

    Squash will thrive nearly anywhere. However, if you want the best success with your squash plants and you want to maximize yields, the conditions below are where it will thrive, (and where it won't):

• Sunny Location: Squash prefers full sun. However, growing it in part sun locations, such as among another crop, can offer relief from the midday sun. Squash needs adequate light for maximum yields. However, it does very well when grown among corn or okra. Squash plants lose a lot of water through transpiration during the hottest days of summer, so this partial shade can help to alleviate that problem. Anything more than this as far as shade could mean a reduction in production and growth; squash is not a good candidate for mostly shaded gardens. In one of my previous posts, I talk about why you shouldn't plant your garden to the north; all of those important notes apply to this sun-loving crop.

• Plenty of Water, Not Swimming: Squash can be planted in a lower spot in the yard and thrive; there is a higher risk of fungal or bacterial issues, though. It shouldn't be planted in the lowest spot where water collects during heavy rainfall, but it's a great candidate for planting adjacent to these areas. Squash plants consume a lot of water, so they can help to mitigate flooding with their consumption. They should never be planted in the flooded areas; just close enough that their roots can take advantage of the resource. Otherwise, you run into issues with anaerobic soil and root rot.

• Avoid Rocky Soil: Squash plants aren't a big fan of rocky soil, but they'll still try to take off. Rocky soil tends to dry out faster, and it's a little harder for roots to run in it. If possible, try to amend the soil with loamy soil, or plant in a raised bed to offer more space for root growth.

• Avoid Allelopathic Plants as Companions: Some plants are allelopathic, which means that they can inhibit the growth of plants that are nearby. Sunflowers are one such plant, but there are many others (including trees.) This goes for a lot of different crops, so be sure to identify all of the allelopathic plants in your yard or seed collection. This will help with future garden planting, preventing plants with stunted growth due to the allelopathic properties of those plants. 

This squash plant was severely stunted by allelopathy, being planted directly beneath my sunflowers. I wanted to test out just how much of an impact sunflowers had on surrounding plants; this seedling is roughly 10 weeks to 12 weeks old. Granted there was some grass to compete with, but the area was tilled, loose, and largely exposed dirt when the pumpkin seed was planted. The sunflowers had a very strong effect on this pumpkin seedling.

The Early Days (before Fruiting)

    As the plants grow, there will be a few chores to keep up with. Squash plants are incredibly easy to care for though and will likely thrive without intervention from you at all!

    Squash plants are fast growing, large plants; they will consume quite a bit of water! Therefore, you'll want to watch for wilted vines. They will naturally wilt during intense heat, especially when highs exceed 90F. The soil may not necessarily be dry, so check soil moisture before watering. The plants generally recover overnight. The rate at which they transpire is quite high, so that's partially responsible for their high water consumption.

    While plants are small, weeding is highly recommended. This will reduce competition for light, nutrients, and water. It will give the plant an opportunity to form a strong root system, sturdy first leaves, and a thick stem that can support lots of leaves, blooms, and fruits.

    Plants need lots of room to run, or a trellis that can support them. I built homemade trellises for my squash and cucumbers (link is the cucumber version), which is quite a savings over buying a trellis or installing a cattle panel. 

    Pests can be devastating while young. Two of the pests I have to keep a close eye on with Butternut squash are cucumber beetles and squash bugs. Cucumber beetles are most devastating during the first 4 weeks in my garden. The squash bugs usually take 8 weeks or so to begin growing in numbers, but control of the adults early in the season can help to delay infestations. This will give your squash plants time to grow and fruit before becoming overwhelmed. 

    When the flowers begin to appear, it's a great time to apply a slow-release granular fertilizer or additional compost. This will continue to feed the plant through the summer, once the nutrients in the compost that you added previously are depleted. 

Fast growing squash vines reached the top of the homemade squash trellis in record time! 

Caring for Butternut Squash Vines at Maturity: Fruiting

    Once the plants have reached maturity and begin fruiting, they're likely large enough that you won't need to weed as often. The large leaves are likely shading the soil, while the vines have started to run at record speeds across the garden. That's a relief, isn't it?

    However, the work is just beginning! You'll want to prune older leaves when possible in the squash patch. You likely have a designated area, and you don't want your butternut squash overwhelming other areas in the garden or yard. Therefore, I recommend a practice of pruning and circling the vines. Prune older leaves, leaving gaps in the canopy of leaves. Once you've done a quick pruning, find the growing tips of each vine that's leaving the designated patch, and redirect it towards a pruned section, where the new young leaves won't be competing with larger leaves. Without pruning and vine redirection, you'll notice that the squash patch will be largely brown and empty of leaves as the vines venture outward, consuming other plants within their path. This results in more work as far as weeding and makes the garden a very confusing space.  

    Squash vines tend to reach maturity right before the worst of the summer heat, so you may experience some troubles with flowering and fruiting. I have a post dedicated to poor fruit production in squash, and high heat (95F+) can be a contributing factor. It doesn't mean you've done anything wrong, just another hurdle that most of us encounter with our squash crops!

    As you may have already discovered, this point in time is when the squash bugs begin forming large, destructive populations. Squash bugs are very difficult to control. However, you'll still have to monitor them and control them to keep your butternut plants alive. Some people opt for conventional insecticides; some use organic insecticides which aren't as effective. There are also creative options, such as removing eggs, or sucking up adults with a handheld vacuum cleaner. There's the board trick too, which involves laying a board at the base of a plant and checking for adults every day; once found, they're squished. I have a video posted over on YouTube which shows how I use soapy water when the squash bugs are out of control. No matter what method you experiment with, it can be a difficult fight and there's not a universal solution that works for everyone.

Roasted, home-grown butternut squash is an absolute favorite around here. A little bit of avocado oil and salt go a long way! It's one of the easiest ways to cook a squash. Wash, split, oil, salt, roast! 

Harvest Time! How to Harvest and Cure Butternut Squash

    So you've made it to harvest, congratulations! Now that you're at the finish line, let's make sure your squash is ready for storage. Butternut squash is a winter squash, and you can store it in your pantry for winter consumption.

Before you harvest, be sure that the butternut squash fruit is ready for harvest. The skin should be pale and hard. Use your fingernail and try to scratch or dent the squash. If you can damage the skin easily, it is not ready for harvest.

If the squash passes the scratch test, it's time to cut it from the vine! Use a pair of pruners and cut the squash with 1-2" of vine. You want to avoid introducing bacterial or fungal infections by ripping the fruit from the vine attachment. 

Once the squash is removed from the vine, allow it to cure in a warm, sunny location for 1-2 weeks. This isn't completely necessary, but it helps to improve quality for storage as well as flavor. It also provides an opportunity for you to inspect the fruits before storing them.

As I just mentioned, you'll want to inspect the fruits before storing them. Look for discoloration in the skin, molding areas, or soft spots. Any of these issues could mean that a butternut squash is going bad and you might want to cut the fruit (removing the bad spots) before it is a complete loss. The squash could be cooked right away, frozen, dehydrated, or pressure canned. It could also be turned into livestock feed. Vine borers can also make their way into the fruits, so be sure to look for any signs of holes or frass. 

    Once cured and the butternut squash has passed your inspection, store it in a cool, dark, dry location for winter use. It's important to remember that squash will lose moisture and the texture may change- this is normal, as most homes have very low humidity levels during winter. This is why cellars were such an important part of homes before the 1950's. They were usually locations that had stable, ideal humidity levels for long term storage of root crops and winter squash crops. See the photo below for an example of moisture loss- do you see the crevices and cavities? Personally, I feel that the flavor of these older squashes, the last to be cooked, is much richer. They seem to age very, very well!

Moisture loss in an old butternut squash. This squash lost some of its moisture in storage. It was cooked in January or February, after sitting in the pantry since roughly July. It was absolutely delicious and safe to eat, but many would question the cracks and air found within the squash. As the squash ages, it does lose moisture.

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