Monday, January 11, 2016

[th]e-Seed: New Year 2016 Edition

Organic, On-Farm Squash Breeding 

Uncle David’s Dakota Dessert squash was bred on our farm by farmer-breeder, David Podoll, Dan’s brother, and we have been refining it for over four decades. It is a winter squash and a buttercup-type variety; a cross between Hubbard, Gold Nugget and other buttercup types.  

     Uncle David's Dakota Dessert squash     

When Dan and I were dating, the first time I came home with him to meet his family, we sat down at the dinner table.  At each plate was a card to rate the squash they were serving as part of the meal.  I didn’t grow up with squash.  I had only eaten it once in my life and it was not a good experience. I didn’t even LIKE squash. Much to my dismay, each of us were to taste-test the squash and rate it for color, texture, and flavor.

When they prepared the squash, the seed was scooped into an aluminum pie tin awaiting its rating cards.  There were tins stacked up on the radiators in the kitchen and dining room from previous meals, with all of their corresponding score cards.  I whispered to Dan, “I don’t like squash.” But Dan asked me to try it. I relented and took a bite. I LIKED it! I LOVED it! And I have enjoyed tasting, selecting, and saving seed from the very best ever since.  

We select for deep orange color, thick flesh, rich sweet taste, smooth texture, vigor, and storability long into the winter. It makes for a delicious side dish and a savory soup.  We use it for all of our baking, including pumpkin pie and quick breads. This workhorse variety is resilient, producing solid yields in variable conditions.  We have heard many stories of the adversity Uncle David's Dakota Dessert squash has endured and about its resilient ability to make a strong come-back. Your gardening success is our #1 goal. Vigorous seed of strong, resilient varieties will keep you gardening like a pro!

Growing Notes
Winter squash is a warm season annual in the Cucurbitiacea family, which includes cucumbers, summer squash, melons, and gourds. The plants need loose, fertile, well-drained soil with sufficient organic matter, a good supply of nitrogen and a pH of 5.8-6.8.  Winter squash is heat tolerant and should be planted in full sun. 

Uncle David’s Dakota Dessert squash requires 95-105 frost-free days to reach maturity.  Seed companies often recommend starting winter squash indoors and transplanting them in northern climates. However, Uncle David’s was bred for northern climates. We direct seed our squash when danger of frost has passed and soil temperatures reach at least 70°F, usually the last week of May. (We are located at the 46th parallel in Dickey County, North Dakota in what used to be Zone 3 but is now designated as Zone 4.)  Black plastic mulch can be used to increase soil temperature for earlier planting. We plant at a 1-inch depth, 2 seeds per foot, in rows 5-6 feet apart.

Our squash is bred and selected for dry-land farming; we do not irrigate our squash or any of our other seed crops.  Our annual rainfall is 18-20 inches.  However, there have been many years that our rainfall fell far short of that. Even then, we don't baby our plants.  They have to grow stronger roots systems and find their own water.  The most successful plants are the ones that produce beautiful, tasty squash, despite adversity. These we select for our stock seed; the seed we will plant back the following year.

During extended periods without rain and under high-heat conditions, Uncle David’s squash leaves will temporarily wilt during the heat of the day. This occurs when the amount of water the leaves loose, due to transpiration, exceeds the water the plants can supply through their root system. During the evening and overnight hours, the plants and leaves will rehydrate and recover from temporary wilting.  If the leaves and vines do not fully recover overnight, the plants are teetering on permanent wilting. Permanently wilted plants may recover when water is added, but prolonged permanent wilting usually kills most species of plants. If you find it necessary to water, use soaker hoses or drip irrigation rather than overhead application; water early in the day so leaves can fully dry, quelling the growth of disease organisms. 

Diseases in Squash

Carefully inspect any wilt you see in your squash patch; make sure you do not dismiss wilting as a water or drought related issue without ensuring that it is not disease related.  Common wilts in squash include Fusarium Wilt, which is caused by the fungi (Fusarium oxysporum).  This can be seed and/or soil borne. Other possible diseases are Bacterial Wilt (Erwinia tracheiphila) and Cucumber mosaic virus; remove and destroy any infected plants.

Wet conditions encourage anthracnose, scab, and fusarium. Prevention strategies are to provide plants with space to avoid a dense, airless canopy, and avoid wetting the foliage to avoid encourage the growth of disease organisms. Powdery mildew can also be reduced by avoiding overhead watering and providing good air circulation. Give plants plenty of space and keep weeds in check to maintain air circulation in the canopy. 


Striped Cucumber beetle feeding can damage young leaves so extensively that plants either die or are stunted in growth. In our experience these insects often appear in our cucurbits after a strong south wind. If the plants are in the two to four leaf stage, they are particularly vulnerable.  The insects target weakened plants first and can literally suck the leaves dry, destroying all of its leaf area. In addition to the feeding damage, these insects can transport diseases, such as bacterial wilt. Prevention strategies include crop rotation and removal of crop debris to discourage overwintering of these pests. Tents can be constructed of fine netting, cheesecloth, or floating row cover to protect young plants.  (Remove before flowering to allow pollinators to do their job.)

When cucumber beetles are detected, hand picking is one strategy, if the bugs are few and far between. Trap crops or companion crops, such as tansy, may be planted to lure pests away from the production areas long enough for your squash to get established. Another strategy is the use of sticky traps and pheromones to lure beetles away from main crop and to the trap them, impeding mating, avoiding a more serious invasion as the season progresses. Sticky traps are also a good pest monitoring strategy, helping you ascertain their numbers.

If pest numbers climb, another strategy is to dip or spray seedlings with kaolin clay to deter the insects from feeding on young plants. You can also combine clay with insecticidal soap, such as Safer BrandTM, or neem oil, such as Ahimsa Neem Oil.

When cucumber beetles become a serious threat for crop loss, PyGanic can be used as a last resort to provide immediate knockdown.  PyGanic contains botanical pyrethrum (derived from chrysanthemum) and is OMRI listed for use in organic production. However, PyGanic also sets your plants back and should only be used if absolutely necessary. If plants are already seriously damaged by the insects, prior to application of PyGanic, application will cause additional injury.

For more information on control strategies, see the ATTRA publication, Cucumber Beetles:
Organic and Biorational Integrated Pest Management, available for download here.)

Squash vine borer is another potential pest.  As the borer boroughs its way inside the vine, it will cause plants to look wilted, even when moisture is plentiful. Uncle David’s squash has the ability to root down at its nodes, providing more resilience in the face of these pests. If you see wilting, check for signs to disease and look for signs of damage along the vine.  If it appears to be vine borer damage, slice open a portion of the stem cutting with the stem, rather than across (do not severe the vine), remove the borers and destroy them, being careful to do as little damage to the vine as possible to aid in healing. 

Harvest & Storage

We cut the squash from the vines about the last week of September, when they are full-size and have a deep rich color. Changing color of the “ground spot” from green to yellow, gold or orange is another general indicator of ripeness. We cut the stem at least 2” from the fruit: a short or broken stem can lead to rot. We let the fruit cure after harvest by keeping in a warm, dry location (usually the garage) for a month. Toward the end of October, we transfer the squash to their winter storage room in the basement, storing them at about 50-55°F with 55-75% relative humidity and good air circulation. 

We closely monitor our cache for any signs of breakdown and immediately cook those up to prevent waste.  (Make sure to carefully and thoroughly remove any areas showing signs of rot before baking or steaming.) We cook our squash from November through February, freezing any excess for use in the spring and early summer months.  

Seed Saving Caution

Squash is cross-pollinated AND insect pollinated. Take caution if you are planning to save seed, as many squash are the same species, Cucurbita maxima. Therefore, they will cross with each other. If different varieties of the same species cross-pollinate, the squash itself will still look and taste like Uncle David’s Dakota Dessert squash; you won’t even know it crossed with anything.  If you save and plant that seed back the next year, it will not be Uncle David's squash; you will get completely different squash throughout your patch.  You now have an interesting science experiment on your hands, rather than good production of predictable quality.

Different varieties of the same species, Cucurbita maxima, must be isolated by at least 1 mile to keep the seed true to type. In addition to the isolation by distance, physical barriers such as shelter belts, orchards, woods and buildings between the fields can further reduce risks of cross-pollination. 

To save seed, harvest the best squash from the best plants, free of any disease.  Let them after-ripen for 3-6 weeks. As you prepare the squash for baking, remove the seeds, rinse in a strainer and dry. Store in a cool, dry place.

We are having Uncle David's Dakota Dessert squash for supper!  Hope you are too!  

Happy New Year to you! 
Theresa & Dan
Prairie Road Organic Seed