Squash Selection to Avoid Common Issues

I have 3 squash problems that keep me from getting good harvests here in NW Missouri: Squash bugs, Squash vine borers (SVB), and mildew.

Members of the C. Pepo family of common pumpkins and summer squash have hollow stems that welcome the SVB to enter and destroy them. So since I have such a strong population of SVB in my soil now, I’m taking a year off from anything in the C. Pepo family which are also prone to mildew and squash bugs.

I have battled these issues before. Vine surgery/wrapping, mildew sprays, traps, etc. But that labor intensity is not worth it to me. So I’ve done some homework and found members of other squash families with resistance to these issues.

The C. Moschata family which have solid stems immune to SVB. These are commonly winter storage squash, but Korean zucchini (Aehobak, Put Hobak, and King Ka Ae) are much like common summer zucchini.  Some members of this family also hybridized  mildew resistance like the Honey Nut (butternut hybrid.) Others from warm climates have natural mildew resistance like the Seminole pumpkin and Thai pumpkin.

The C. Mixta, aka C. Angyosperma family is small, containing mostly variants of the Cushaw squash. These have the trinity of resistance to squash bugs, SVB, and mildew.

The C. Lagenaria family is gourds, but the Cucuzzi snake gourd is eaten like summer squash before it matures. I’ve had the same experience with Luffa from this family, perfectly tender and edible when young.

So 2023 shall be the Summer Of Weird Squash for me! I plan to grow the 6 varieties I mentioned. If you have any experience in these or input on this plan, please do share.

Great pics! Thanks Matt for the info on which types have less hassles with pests and diseases, much appreciated.

I have had borers in the past and found dealing individually for each plant a pain in the butt.

I'll be trying this with the squash for now and the pumpkins further down the track as the seasons here are opposite yours.

Thanks for writing this. It’s very useful information. I have been in a similar situation, though mildew has been the problem her, especially since it spreads, and I like to mix different plant’s together where they grow. I am not planting zucchini, for that reason alone, this year. I am planting butternut and buttercup instead. I am also planting delicata and Long Island cheese pumpkins.
Where did you find the information about the different families, and which squash is in each?  I would like to read it. Thank you.

Joseph Lofthouse has been doing a lot of crossbreeding and I believe some were squash family so he may have crosses with c. Pepo and c. Moschata that would be fun to try.

My story sounds very similar. I've pretty much given up on C. pepo squash because of squash vine borer, squash bugs, and powdery mildew. I've grown a few other varieties in the past and plan to add to my options this year.

Of the C. moschata varieties, I'm adding zucchino rampicante this year.

I had amazing success growing sponge luffa (Luffa aegyptiaca), with zero pests bothering it. I've heard ridged luffa (Luffa acutangula) has a better flavor for eating and am going to grow it this year.

I grew cucuzzi once, and every fruit had sticky brown sap running from tiny holes. I'm assuming it was caused by a bug, but I never figured out which one or what to do about it.

I tried to grow Seminole pumpkin once, but the deer ate every plant to the ground. I've improved my fence and am going to grow it again this year. It looked promising before the deer got it.

I haven't tried cushaw squash or other C. mixta varieties. I'm adding those and the Korean zucchinis to my list. Sounds like a fun upcoming garden season for us both!

In the south here and have found the cushaw, trombocino, and cherokee tan pumpkin have the least problems. I don't worry if they cross pollinate.

Because of squash borers, I’ve pretty much been limited to growing pepo squash under the insect excluding shade cloth of my hoop house (which I designed to easily exchange the winter greenhouse film for summer 30% shade cloth, greatly extending the life of the greenhouse film) while only growing Seminole squash and Cucuzzi gourd outside.  In the hoop house, I grow mostly parthenocarpic summer squash cultivars augmented with manual pollination.

For the past few years, I’ve been conducting an experiment with Yellow Straghtneck squash where each spring I’m replanting seed from the squash plants that last the longest before succumbing to borers.

I’ve also noticed that the invasive needle ants, which invaded my garden 6 years ago (where they totally eradicated the equally invasive fire ants) like to make their nests in hollow items like unused garden hoses and the hollow stems of dying pepo squash that were opened to the outside by the exit holes made by departing borer larvae.  I’ve been experimenting with drilling a couple of small holes in the stems of young squash pepo and maxima squash plants in the hopes that needle ants would take up residence and devour any hatching borer larvae seeking to move in.  Last year, I did this to a Blue Hubbard plant, which normally gets killed before reaching the age of flowering and was able to get fruit from it.

In addition to fire ants, needle ants have greatly reduced the populations of slugs, snails, hammerhead worms, and earwigs in my garden.  Needle ants do have a sting, but usually I only get stung by 1 or 2, unlike the mass attacks you can get from fire ants.  Needle ants only sting when you put your hand down on them or they get pinched under your clothing unlike fire ants that sting as soon as they get on your skin.  The pain from a needle ant sting sneaks up on you and comes and goes for about a half hour, making a welt like a sweat bee sting which itches slightly for a day.  Also, having been stung a number of times by needle ants, I’ve noticed that I have less of a reaction to yellowjacket and paper wasp stings. Of the two invasive ants , I’d much prefer needle ants, since they’ve turned out to have a number of uses in the garden.  They are also present in much lower numbers in the garden than fire ants so you don’t encounter them as often.

First, I'll note that Carol Deppe in Oregon grows C maxima and not moschata, because in that climate (dry in summer, less heat in summer) the borers aren't a problem and the moschatas don't complete growth well. Here in West Virginia, I'm always trying new varieties and I find the maximas never produce much--whether it's because of borers or something else I don't know but I've given up on maximas. I don't seem to have any problems with pepos, but I grow only summer squash, not any "pumpkins." I note that the last three years I tried starting a late crop of summer squash to replace the old, declining plants, in July or early August, and all three years they didn't thrive if they germinated at all. Maybe they need row cover for grasshopper protection--no problems with planting  summer squash in May. I've grown the cushaws a couple times--they did fine, the only problem is what to do with that much squash at once. Mostly my standby is butternuts, though some other moschatas have done acceptably well. Last year my butternuts were hit pretty hard by mildew, so I found a strain that's supposed to be resistant to try this year. I'm also going to grow the Tahitian melon squash, for the second time--it's like a butternut that has been stretched extra long, with a curve. I grew it once and it was fine, maybe even sweeter than butternuts and long keeping, but again what do you do with that much squash? I'm also going to try delicata because my daughter asked for it. I grew Seminole twice. The first year I grew it near corn, and it didn't start flowering until September, and then flowered so relentlessly that I had to pluck baby squash daily in hopes that the first ones might make it to maturity. I blamed the shade from the corn. The next year I grew it again, this time in full sun, and--same thing. Didn't get a single usable squash either year, so I have no interest in trying that one again, ever.
Now on the squash bugs--the first year here, I got them, pretty bad by the end of the season but my butternuts were ripe so I didn't care. I didn't do a garden cleanup. The next spring I could not grow any cucurbit, even melons, because a healthy crop of squash bugs had overwintered in the mulch and relentlessly attacked any baby cucurbit. I learned my lesson, and now when I pull any squash plant I throw it where my chickens can work it over, and remove all the mulch before winter and throw it on a woods compost pile. I also police my squash plants every two to three days, removing the eggs and nymphs and adults--kindofa pain because you have to check every leaf...it was handy, the year my summer squash were next to my water spigot--while my watering can was filling I could check a few leaves.

As always, when you are dealing with a specific pest, it pays to know their life cycle:
https://en.wikipedia.org/wiki/Squash_vine_borer
I never had encountered the problem until I chose to grow some winter squash, cucurbita maxima Buttercup squash, over a plastic film [to save myself some weeding, I thought foolishly] The entire crop died and I was left with infected soil.
"Eggs hatch in about 10 days and larvae bore into vines within hours. Larvae feed for 25-27 days and then leave plants to pupate 1-6 inches under the soil. Moths emerge from these pupae the next summer. In Michigan, there is one generation of squash vine borer per year.
So says this site:
https://www.canr.msu.edu/news/squash_vine_borer_biology_and_management#:~:text=Appearance%20and%20life%20cycle&text=Eggs%20hatch%20in%20about%2010,squash%20vine%20borer%20per%20year.
I believe my problem was made worse by placing a plastic film: It also gave protection to the bug as I didn't use my hoe to remove any weeds near my squash, so they had free range...
At the first yellow leaf, I will be on the lookout next time.
For me here, in Wisconsin zone 4, my protection would come in the winter: tilling down to 6 inches might winter kill most of the critters.
Down in Southern climes, you may not have such luck as there may be more than one generation/year and the cold may not be low enough to outright kill them.
If you don't care to use dangerous pesticides, there is always companion plantings: Look at number 15 in this site
https://drecampbell.com/natural-ways-get-rid-squash-vine-borers/#:~:text=These%20pests%20do%20not%20like,the%20squash%20vine%20borer%20moth.
The Old Farmer's Almanac suggest this:
Sprinkle diatomaceous earth around the stalks when the squash vines are small or the threat of squash vine borers is high (early to mid-summer). Reapply after rain. Also, build up the soil around the vines. Or, sprinkle black pepper around the plants as a defense.
I like the D.E idea myself.
I wish you good luck against these bugs for your next growing season, and thanks for detailing the squashes that are least likely to be infested..

Check out this work by Dr. Drystra  in a nut shell if the plant as 12 Brix it with not be attacked by bugs.

https://youtu.be/bnNOvA3diDU.

Joseph Van Wyck wrote:Check out this work by Dr. Drystra  in a nut shell if the plant as 12 Brix it with not be attacked by bugs.

https://youtu.be/bnNOvA3diDU.

My next  question, of course, is going to be : could you alter the brix of plant leaves?

hey Matt,
We tried the Cucuzzi gourds last summer and they were beautiful and grew well. But we found them almost unpalatable. So we let them keep growing and are making digeridoos out of the longest ones. probably will not grow them again for food.

Our favourite for mildew and squash bug resistance is a moschata called tromboncino. They can be eaten like a summer squash when young and mature like a butternut when full grown. Flavour is mild and kind of nutty when young. Firmer texture than a zucchini. Stores really well. And they grow BIG! we got 8 4 foot squashes from one plant. We let it grow up and over a tree as a kind of trellis.

Cecile,
We've worked for years to raise the brix of our plants. Yes, absolutely, we can change the brix of the entire plant including the leaves.

One thing I read recently though is that the 12 Brix works best on sucking insect pests and maybe not so good on chewing or boring insects.

Sunny Baba wrote:Cecile,
We've worked for years to raise the brix of our plants. Yes, absolutely, we can change the brix of the entire plant including the leaves.
One thing I read recently though is that the 12 Brix works best on sucking insect pests and maybe not so good on chewing or boring insects.

Thanks, Sunny. I can understand that boring insects have a different skill set... Back to hoeing in early winter and sprinkling D.E near the young plants....Aargh.
BTW, how do you change the brix of a plant? I had extra winter syrup from my hives one year and I poured it in my tomato patch. I didn't notice a change in taste in the tomatoes that survived the ant invasion, LOL.

Sunny Baba wrote:Cecile,
We've worked for years to raise the brix of our plants. Yes, absolutely, we can change the brix of the entire plant including the leaves.  

webpage that nay help

So, how can we improve our rates of photosynthesis and therefore increase quality, yield and natural
defenses of the plant? How do we improve the process?
When we consider the question, we need to look at how the plant is grown and how we can reduce
nitrate and chemical input; both of which will reduce Brix levels.
N: The big unknown today is Nitrogen. If you examine the molecule for chlorophyll it can be
seen that N is essential for its’ make up, but excess N can bring too much water into the plant if
it’s applied as NO3. It’s important to remember this when we start to build Brix levels. We are
always looking at various ways of applying different types of N to decrease water within the
plant to increase Brix levels. We have recently reduced recommendations of NO3 and started to
use urea and ammonium nitrate as foliar applications and are having great success.
P: As mentioned earlier, phosphate is essential to sugar movement within the plant.
K: K is important as it controls the opening and closing of the stomata. As with N, excess
Potassium can also enter the plant in non-phosphate form along with water and cause
problems.
Ca: Calcium is involved in many pathways in plant cells, including plant growth and
development, resistance to environmental stress
Mg: Magnesium controls the amount of N in the leaf to avoid an excess building up.
Note that the chlorophyll also contains carbon, hydrogen, oxygen, nitrogen and magnesium.
We will use some form of a humic substance to partner up with magnesium that speeds up the
metabolic process and makes sure there is enough magnesium for photosynthesis. We see that when
coupled with a humic substance, this will help liberate C02 from the soil calcium carbonates thus making
C02 available to the plant through the roots. The humic substances will also stimulate plant enzymes
which further aid the production of sugars in the plant leaf.  

Sunny Baba wrote:hey Matt,


Our favourite for mildew and squash bug resistance is a moschata called tromboncino. They can be eaten like a summer squash when young and mature like a butternut when full grown. Flavour is mild and kind of nutty when young. Firmer texture than a zucchini. Stores really well. And they grow BIG! we got 8 4 foot squashes from one plant. We let it grow up and over a tree as a kind of trellis.

I grew tromboncino or rampicante this year for the first time and can echo these comments. Very productive so plenty of young summer squash. A little larger and they stay solid in the freezer. A winner for sure.

Ulla Bisgaard wrote:Thanks for writing this. It’s very useful information. I have been in a similar situation, though mildew has been the problem her, especially since it spreads, and I like to mix different plant’s together where they grow. I am not planting zucchini, for that reason alone, this year. I am planting butternut and buttercup instead. I am also planting delicata and Long Island cheese pumpkins.
Where did you find the information about the different families, and which squash is in each?  I would like to read it. Thank you.

I use a variety of sources (and cross reference them so I'm not relying on any one source) but one surprisingly good source for categorizing is Wikipedia https://en.wikipedia.org/wiki/Cucurbita

I recall reading that Long  Island Cheese is susceptible to mildew, so if you've had that issue with other varieties you might have it with this one too. There are other ways to avoid it, like trellising to get it high and dry. But the only squash truly immune are hybrids bred to avoid it or deep-south species that are used to high humidity.

Ulla Bisgaard wrote:Thanks for writing this. It’s very useful information. I have been in a similar situation, though mildew has been the problem her, especially since it spreads, and I like to mix different plant’s together where they grow. I am not planting zucchini, for that reason alone, this year. I am planting butternut and buttercup instead. I am also planting delicata and Long Island cheese pumpkins.
Where did you find the information about the different families, and which squash is in each?  I would like to read it. Thank you.

Reputable seed companies will also have on their packets the type of squash/pumpkin it is. Around here, we get  Cucurbita argyrosperma, C. maxima, C. moschata, and C. pepo, not so much the C. Ficifolia, which appears to be grown more for its seeds.
If you have lots of room you might want to grow one of each kind as they do not seem to cross pollinate much, so you could save the seeds.
But if you grow 2 moschata or 2 maxima, you can't trust that the seeds you get will be true to the parent.
Seed people, if you are listening, it would be nice to have bush categories for all these vines as it would enable folks to grow more foods in the same amount of land. [Walking and cleaning around the plants is easier too as you don't tangle all over in the vines!]

Matt Todd wrote:
I use a variety of sources (and cross reference them so I'm not relying on any one source) but one surprisingly good source for categorizing is Wikipedia https://en.wikipedia.org/wiki/Cucurbita

I recall reading that Long  Island Cheese is susceptible to mildew, so if you've had that issue with other varieties you might have it with this one too. There are other ways to avoid it, like trellising to get it high and dry. But the only squash truly immune are hybrids bred to avoid it or deep-south species that are used to high humidity.

Yes. Once I started doing the same research as you, I saw that. I am going to plant cinnamon girl instead, which is more resistant. It turns out, that the seed company I used, does have the information about pm resistance in their seed catalog. It’s just not on their website.

Here in the Missouri Ozarks near Salem I’ve grown grown Seminole Pumpkin (from Southern Exposure Seed Exchange) with great success. About 2 plants out of 21 succumbed to squash bugs with no spraying. The rest lived on and the resulting pumpkins all lasted over a year at room temp in our house (72-75). Many lasted over a year and a half and the last of them just over two years. They get less sweet and more starchy the longer stored for sure. I tried a cushaw type from Baker Creek, “Illinois”, and it did terrible. Some plants survived, but the resulting squash where just eaten up by bugs, squash bugs all over them, trails all over the skins, rotting easily. The couple I saved from the bugs and peeled all the nasty skin off didn’t taste good, very bland, and they were very watery.

Katie Anne wrote:Here in the Missouri Ozarks near Salem I’ve grown grown Seminole Pumpkin (from Southern Exposure Seed Exchange) with great success. About 2 plants out of 21 succumbed to squash bugs with no spraying. The rest lived on and the resulting pumpkins all lasted over a year at room temp in our house (72-75). Many lasted over a year and a half and the last of them just over two years. They get less sweet and more starchy the longer stored for sure. I tried a cushaw type from Baker Creek, “Illinois”, and it did terrible. Some plants survived, but the resulting squash where just eaten up by bugs, squash bugs all over them, trails all over the skins, rotting easily. The couple I saved from the bugs and peeled all the nasty skin off didn’t taste good, very bland, and they were very watery.

Welcome to Permies, Katie. would you know what type of cucurbit it is? This is what the Wiki says:
"The five domesticated species are Cucurbita argyrosperma, C. ficifolia, C. maxima, C. moschata, and C. pepo. All of these can be treated as winter squash because the full-grown fruits can be stored for months; however, C. pepo includes some cultivars that are better used only as summer squash."
I'm also saying that because the Survival Gardener posted an article on Seminole Pumpkins but the pictures associated with it have many different shapes and colors and tastes. I suspect that these folks may have planted several squashes/ pumpkins of the same type and they cross pollinated with ... something else?
https://www.thesurvivalgardener.com/rabbit-trails/the-seminole-pumpkin-project/
If a person is careful to plant only ONE of each species, [and have enough room to do so,] they should be OK and the fruit should be true to type. Cucurbits seem to cross pollinate within their own species but not across species.

I found the discussion of the "Brix" fascinating.

Since this was a new word to me.

Maybe everyone's problems could be solved by building soil health?

Bryant said, "Plants that are healthy will not be sought out by pests animals as readily as those plants that are not getting the nutrition they need, these "sick" plants send out chemical messages that attract the insects that love to feed on the plant, these "sniffles" can be in the form of exudates, pheromones released through the stomata to the air and through electrical messages that travel through the fungal network as well as the root surrounding soil. These are the reasons composts teas are usually recommended to be sprayed on the trunks, branches and leaves of plants.

https://permies.com/t/102935/soil-food-network-works#864722

How many folks with pest problems use wood chips?

https://permies.com/t/120453/Great-Wood-Chips

Companion planting works very well for me in dealing with squash bugs and vine borers. In particular, I find that Nasturtiums are great for squash bugs (you can only plant these in the spring: they will do well until the summer heat sets in, then they will just hang in until they go gangbusters in the fall, so if you are going to plant multiple beds throughout the summer, get those into all of them in the spring) and dill fools the vine borers. In fact, while the squash bugs will eventually find your plants even with the nasturtiums (though you can hold them off a bit longer by using row cover until the plants begin flowering), by the time they do, your plants will be sufficiently well established that they will not be too bothered by them. But the dill? It is a game changer. Since I started planting dill in my cucurbit beds, I have not lost a single plant to the vine borers. Not one. And dill is so easy to plant! Just throw the seeds out there and you will have it growing everywhere. Oh yes, and let the plants go to seed and it will come back again and again. Using these two methods I easily get six weeks or more from my summer squash varieties and tons of winter squash as well.

Marisol Laylin wrote:Companion planting works very well for me in dealing with squash bugs and vine borers. In particular, I find that Nasturtiums are great for squash bugs (you can only plant these in the spring: they will do well until the summer heat sets in, then they will just hang in until they go gangbusters in the fall, so if you are going to plant multiple beds throughout the summer, get those into all of them in the spring) and dill fools the vine borers. In fact, while the squash bugs will eventually find your plants even with the nasturtiums (though you can hold them off a bit longer by using row cover until the plants begin flowering), by the time they do, your plants will be sufficiently well established that they will not be too bothered by them. But the dill? It is a game changer. Since I started planting dill in my cucurbit beds, I have not lost a single plant to the vine borers. Not one. And dill is so easy to plant! Just throw the seeds out there and you will have it growing everywhere. Oh yes, and let the plants go to seed and it will come back again and again. Using these two methods I easily get six weeks or more from my summer squash varieties and tons of winter squash as well.

I was just thinking yesterday about what herbs might foil borers! Thanks for the suggestion.

Do you plant the dill before or after the squash?

Mk Neal wrote:Do you plant the dill before or after the squash?

I plant the seeds / seedlings at the same time. If anything, err on the side of the dill being bigger - it is so feathery and light that it will not hinder other plants.

Thanks, Marisol for the dill suggestion with squash. Since dill can take 10-21 days to germinate, it might be to my advantage to get dill plants [of known height already] to intersperse in my cucurbit plantings.
The cucurbits will take off quite quickly once the oil is warm and will catch up to the dill

This is a very helpful discussion as I’m about ready to plant sugar pumpkins, butternut squash & zucchini. I’m in zone 7b & the vine borers are brutal here.
I bought a big bag of diatomaceous earth…so I’m ready! And I plan to make compost tea as another insect repellent & soil enhancer.
But while reading this thread I am completely baffled by the discussion of brix! What on earth is this? What does this have to do with vine borders? Help!!!

Gaurī Rasp wrote:This is a very helpful discussion as I’m about ready to plant sugar pumpkins, butternut squash & zucchini. I’m in zone 7b & the vine borers are brutal here.
I bought a big bag of diatomaceous earth…so I’m ready! And I plan to make compost tea as another insect repellent & soil enhancer.
But while reading this thread I am completely baffled by the discussion of brix! What on earth is this? What does this have to do with vine borders? Help!!!

I suggest you ignore the brix discussion. It's rather silly IMO. Yes, an unhealthy plant will be more prone to pests. Also yes, we grow the most healthy plants we possibly can. Also also yes, we get vine borers regardless and will always need other ways to combat or avoid them.

After several years of struggling with zucchini and yellow squash, I've switched 100% over to tromboncino squash.

Resistant to SVB and most diseases.

Produces both summer and winter squash (just depending on if you let them fully mature).

Concentrating on this single variety allows me to avoid undesired cross-breeding.

It creates a very large vine (30-40').  This can be a problem for some, but under the right circumstances is a real asset.  I have limited raised bed space for vegetables.  However, I've taken to growing a couple of tromboncinos up a fruit tree in my mini-orchard.  The vines grow up the first tree and then spread out in the tree canopies.  The fruit is produced earlier and squash comes later, giving me two harvests each year from those trees with no garden space used.

I'll be planting cucuzzi squash again next year!

Zucchino rampicante and luffa either didn't like where I planted them or didn't like the weather. They were both stunted at a few inches tall, and ants took over the rampicante.

C. moschata pumpkin vines looked great until deer ate them to the ground.

The volunteer C. pepo produced a little before squash bugs found it, and then deer ate it, too.

But the cucuzzi. The cucuzzi!! Squash bugs and vine borers have left it alone. Deer haven't nibbled it at all, even though it's growing along the fence. It grows and produces whether there is heavy rainfall or no rain. It's soft leaves aren't unpleasant to harvest among, like many of the squash family with prickly leaves.

I've tried a few cooking methods to see how cucuzzi compared to common zucchini and summer squash. The smell of raw cucuzzi is different and not something I currently find appetizing, but the cooked smell is mild and much better. My toddler likes zucchini in the air fryer, but she took one bite of air-fried cucuzzi and said no. Otherwise, it's been great. We've enjoyed cucuzzi squash particularly in soup and squash bread.

A bit late to this thread, but...

Another vote for cucuzzi! I am done with any other summer squash. Zucchini died a horrible death (mostly SVB). In general, summer squash had never done well for us.

After doing squash surgery cutting out the borers from our candy roasters (maxima) all summer, we got 6 large squashes to maturity from 3 plants. I tried injecting with BT, burying the stems, etc.. Can't wait to try the dill suggestion! I am surprised they survived and matured.

Butternuts got attacked by bears (while immature) and this lead to rotting. So far, not that impressed with butternuts after 4 attempts or so. I would love to try a new moschata, particularly Cherokee tan pumpkin - but cannot find the seeds anywhere this year. I am also considering a moschata landrace, a Lodi, or black futsu. At least the SVBs didn't get the butternuts.

As far as pepos, Candystick Dessert delicata did pretty well this year despite the SVB attacks. Way better than zucchini.