Two Ways to Grow Squash for Seed Saving Even in a Small Garden

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There are a few varieties of squash my family cannot do without. We require spaghetti squash with sage and browned butter in the summer, pumpkin for pies in the fall and if there was no butternut squash with bacon crumble for Thanksgiving, there would be a riot at the dinner table. And don’t forget Grandma’s zucchini bread. So, how do I save seeds without the squash crossing until they are all one inedible warty squash mutant?

Lazy Gardener Methods

Kakai PumpkinIt’s easier than you might think even though the fat, black Carpenter bees in my garden love squash flowers and will happily mix pollen from one flower into another all day long. There are four main species of edible squash. The ‘Rugosa’ Butternut squash I favor is from the species Cucurbita moschata. To keep it from crossing all I need to do is keep it away from other squash I want to grow that are in the same species. For us that means the ‘Tromboncino’ that we often use in place of a true zucchini needs to be as far away as possible from the “Rugosa’ patch.

I can grow the spaghetti squash that we like right next to the “Rugosa’ because the spaghetti squash is a Cucurbita pepo. But it can’t be near the pie pumpkins because they are also C. pepo. As long as you know which species of squash you are growing, you can separate them enough to prevent most cross-pollination. I do this by growing one variety of each species in front of the house and one behind. You could plant on either side of a hedge or other windbreak and do a pretty good job of keeping your variety breeding true. Or you can separate the plants with time. If I put in my spaghetti squash very early from transplants, or under a row cover, or both, and I don’t plant out my pumpkins until the spaghetti squash have each set a few fruits, then I can grow the pumpkins right beside my developing squash and pinch off any extra flowers that try to develop on the spaghetti squash plants once the pumpkins start to flower.

Precision Gardener Methods

Hubbard Squash

A Mother of a Hubbard

If you are determined to maintain a squash variety with maximum purity, you have several options. You could alternate years of growing for varieties that are in the same species. Year One I would grow ‘Rugosa’ squash and then can or freeze what we would need during Year Two when I would be growing the ‘Tromboncino.’ But even then, a bee from a neighbors garden could stop by and ruin things inadvertently. You could alternate days, or even weeks, when you “cage” one of the varieties or the other. Large sheets of row cover are best for this with squash and you would have to be sure you tucked in the edges and laid a board or something heavy over them to make sure they didn’t blow off exposing both varieties to insects at the same time.

Or you could hand-pollinate, which sounds fussier than it actually is. You have to keep an eye on your squash blossoms as they develop and know which are male and which are female. And you will need to tape the female flowers that you want to hand-pollinate shut to prevent them from opening on their own, ideally the night before they would have opened. You pollinate that flower with pollen you know came from a male flower of that same variety and then you tape that flower shut again and tag the baby squash behind it so you can save the seeds only from the tagged squash. If I’m making this sound complicated, check the videos or instructions available on the Internet. This is the best method if you are preserving a rare variety, a family heirloom, an unusual squash where you won’t be able to easily get more seeds, or if you are saving seeds for trading and sharing.

If you have favorite seeds saving methods for squash, we would love to hear them. Please share in the Comments.

Squashing the Whitefly Invasion


It must be August, because my squash leaves are starting to look pretty sad in places. I noticed the beginnings of a whitefly problem a few nights ago and tested a new do-it-yourself spray on a group of leaves. Two days later, the test leaves looked great, but the rest of the squash patch was starting to show more serious signs of infestation. Today I sprayed the top and bottom surface of every leaf I could find with evidence of whiteflies and then some. I’ll track the results in a few more days and update things here.

The varieties of squash in the patch are:

‘Vegetable Spaghetti’ (C. pepo)
‘Candy Roaster Melon’ squash (C. maxima)
‘Upper Ground Sweet Potato’ (C. moschata)
and ‘Jim’s Butternut’ (C. moschata)

This last one was saved from ‘Waltham Butternut’ many years ago and kept going by a neighbor. It grew 25 foot vines with 10 fruit on a single vine in 2012. If some of that productivity crosses into my ‘Upper Ground Sweet Potato’ seeds for next year, maybe it will be a good thing!

The ‘Spaghetti’ squash is suffering the most from the whiteflies, though I first noticed it on the ‘Upper Ground Sweet Potato’ leaves. Maybe I didn’t notice it on the ‘Spaghetti’ squash because it’s harder to get to their part of the patch? The ‘Candy Roaster Melon’ is clearly the least affected. It’s much slower growing than the other varieties and is just now, in August, starting to flower. I have yet to find any research on differing vulnerability to whitefly across squash species, so the differences I see may have other causes. It is certainly too early to say that C. pepo is more likely to suffer whitefly infestation and C. maxim is more likely to fend it off—but that’s a theory that might turn out to be worth testing.

Homemade Whitefly SprayThe spray that I made started with 1 Tsp of Dawn Advanced Power liquid dishwashing soap mixed into 1 cup of vegetable oil. This makes a concentrate that you then mix with water in your sprayer. Add 1 1/2 tsp of the concentrate for each cup of water you add into the sprayer. I mixed 3 cups worth at a time in my regular household spray bottle. Next time I will seriously consider a backpack sprayer. In order to control whitefly everything I have read emphasizes the need to spray both the tops and the underside of the leaves. This can quickly become a tedious and finger-numbing project with your average spray bottle.

Next year I will plan ahead. The U.C. Davis Integrated Pest Management site says, “Several wasps, including species in the Encarsia and Eretmocerus genera, parasitize whiteflies. Whitefly nymphs are also preyed upon by bigeyed bugs, lacewing larvae, and lady beetles.” Buglogical has additional suggestions to try. If I manage to establish populations of these good bugs in my garden before August next year, maybe we won’t see the whiteflies at all.

Do you have a whitefly cure that works well in your garden? Please share it in the comments. And if you have tried something that didn’t work, I’d like to hear about that as well.

Updated August 31, 2013

The spray has had mixed results. The plants are still going, and new fruit is even being set, but there is noticeable damage from this pest on a number of leaves. Below is an example from the ‘Butternut’ patch.

Butternut Squash Leaves

Butternut Squash leaves treated with homemade whitefly deterrent.

The growing tips look healthy and you can see at least one young squash has been set during the Whitefly/Mildew invasion. But a number of leaves may have been too damaged to recover. And the nastiness is clearly spreading again.

Spaghetti Squash Leaves with Whitefly or Mildew

Both sets of leaves you see here are from the same Spaghetti Squash, one clearly much more affected than the other.

Only the few five-fingered leaves you see here are not from this plant. Seeing these leaves so close together, clearly growing in the same conditions, makes me wonder about the variability for disease resistance in these squash.

Watching the Squash


Squash-ClockThere are no zucchini plants in the Dirt to Dinner garden, for reasons that will be obvious to you by August, if they aren’t already. ;-) Instead I’ve been trying to learn more about the squash varieties we do have going. For instance, did you know that the ‘pumpkin’ you buy canned to make into pumpkin pie is actually a squash that is most closely related to Butternut? I’m loving all the details available at Watch Your Garden Grow, from the University of Illinois Extension. It even includes recipes!

Spaghetti Trellis

Spaghetti Trellis

So far, the most vigorous grower we have out in the garden is the Spaghetti Squash which we are hoping to convince to grow up the trellis we have so generously provided just for this purpose. Unfortunately, the plants have designs on the wide open spaces in front of them and keep growing away from the trellis which backs up against theshade of the bushes that edge the garden. We could actually consider relocating the trellis, but there are still carrots and big white Icicle Radishes growing where it would need to go. Note for next year: Squash trellises need to be on the sunny side of the squash plants.

Net Lonving Squash?

Net Loving Squash?

At least the mystery squash seems happy to give it a try. Though, in my heart of hearts, I’m worried that this might actually be a cantaloupe plant of some kind. I’m not actually sure how to tell the difference. If it has big triangular leaves with spiny stems and sends out those little twisty tendrils that cling onto other plants and –hopefully–trellis netting, it could be anything from a Delicata to a cucumber as far as I can tell right now. I better go back to my website on growing squash to see how much more I can pick up.

Delicata Shade Crop

Delicata Shade Crop

These guys I am pretty sure really are Delicata. They are a Compact Winter Squash from Renee’s Garden that gets great reviews for growing well and tasting a lot like sweet potatoes, which most of the kids are happy to eat. I took this picture just before I thinned them down to the recommended “2 strongest plants per hill.” I could have carefully pricked out the extra plants and moved them to a sunny spot so we could see exactly how much difference the sunlight would make, but it’s starting to feel like there’s an awful lot of squash growing around here. There are eight of the compact Winter squash plants left after thinning, half Delicata and half Early Butternut. There are at least twenty plants representing the dozen different varieties mixed into the Zucche in Miscuglio we got from Grow Italian with names like Tonda Padana, Serpente Di Sicilia and Berrettina Piacentina

Pre-Colimbus Natives

Pre-Columbus Natives

And, not to worry, it’s not *all* Winter squash. There are two Summer squash plants that I know of in the garden. They are Golden Scallopini Bush squash from Seeds of Change. It’s a rare native American cultivare that predates Columbus. And it makes small 3-6″ squash with a flying saucer shape that I hope will appeal to the kids.