Pumpkins as a drought tolerant crop?

Hi,
I'm new and this is my first post--if I'm supposed to be doing something differently, please let me know.

I saw a BBC article https://www.bbc.com/future/article/20231026-are-halloween-pumpkins-a-future-superfood about pumpkins and they showed pictures of them growing them in "mini deserts".

From the article:
"Pumpkins are an ideal plant for water insecure regions due to their tolerance of drought. Given their ability to withstand less water and salinity..."

I'm gardening in coastal southern California (zone 10) with some watering limitations. I've never had success growing things like pumpkins (they get toasted and don't produce anything, then die), and I haven't seen them much in my neighborhood, either. I always assumed it was a combination of the arid climate, the soil, and the space restrictions in an urban setting. From this article, though, it looks like they should be great for my drought tolerant garden, so I'm wondering if I'm missing something. Has anyone had similar experiences to what the article is describing? They mention that they are working on breeding better pumpkins, but the pictures in the article show pumpkins growing in the sand now, not in the future.

The only squash type plant I've had success with is chilacayote (I think it's also called fig leaf gourd and shark fin melon). I grew one several years ago in a different location, and I started one at home at the end of this summer since it seems to do better with cooler weather. Because it's perennial my hope is that it will survive long enough to fruit. It's still one of the most thirsty plants in my garden, though--and that's with the vines almost all being on a covered porch.

Any advice or information you have about pumpkins as a drought tolerant or low water crop would be appreciated. This article made me really curious. Thanks!

Welcome to the forum.

It would have been nice if that article told what variety of pumpkins they were growing.

Seminole pumpkin would be best my guess though this study might help to explain:

https://www.sciencedirect.com/science/article/abs/pii/S0378377419304901

Taste might also be a factor:

Joseph said, "I consider the pepo pumpkins unsuitable for human food. Sure people eat them, but only after adding a ton of sugar and oil.

I find the best pepo flavor in Acorn/Delicata. They could be crossed and/or selected for larger fruits.

https://permies.com/t/226879/Pepo-Winter-Squash-list-prospects#1950235

When a person purchases a can of pumpkin, I believe they are purchasing "Delicata".

Lydia, thanks for the link! You're not alone in being unable to grow pumpkins without irrigation. I had the same issue this past very dry summer.

I think the article is not at all well-written or especially factual! Some of the areas they discuss like Goa are coastal tropical with very high rainfall. The "mini-deserts" they describe are very different to your climate and more like the PNW with a wet season and then a dry season. The sand is flood-deposited during the five months of heavy monsoon rains that make the rivers overflow their banks. So the layer of sand probably covers better quality water-filled soil that the sand keeps moist. The pumpkin roots are probably going down into the better, moister soil rather than simply growing in all sand as the article implies. The sand is acting as a mulch keeping the moisture locked into the deeper soil during the dry season.

And the next photo down shows pumpkin seedlings in what are probably compost-filled Zai pits that are clearly being watered.

I would love a palatable, productive, drought-tolerant pumpkin!

I have grown pumpkins for years. Every pumpkin I've ever nurtured has grown bigger with the more water they receive. Smaller with less. Maybe you could grow pumpkins in low water areas. I don't know. But I wouldn't think they would have much size.

To sum it up: I suspect that the plants can tolerate constant high ambient temperatures, but I doubt they could resist having little water. Landrace pumpkins and selective breeding might help strengthen these traits.

The details:
We grew pumpkins here at Wheaton Labs (zone 4-ish to 5b) this year, which has a very hot, dry one-and-a-half months in the middle of summer. They produced okay for the first year, though it didn't seem effortless and I suspect that if we didn't have so much water (a new well was installed at the start of the summer), then they too would have dried-up.

What we saw happen with them was they started growing a short time after planting: about mid-July. Several of them sprouted and showed a lot of promise. The entire month of August however, most of our plants went dormant because it was so darn hot. Then about halfway through September there was a bit of rain and things cooled down significantly. The dormant plants made up for the lost time, pumpkins included, and there was most definitely a boom in squash production.

I also suspect that - like the article mentions - the type of pumpkin makes a difference. It sounds like that university in Turkey is looking to develop a landrace pumpkin that is tailored to that specific climate. We'll see how our seeds do next year, and/or if any volunteers show themselves.

Hi Anne--thanks for the welcome! I agree that it would have been nice to know the variety of pumpkin that they were growing in the article. Maybe the fact that they didn't list any of that kind of information should have been a red flag... Based off of the article you shared it looks like pumpkins are relatively drought tolerant, meaning that they are more drought tolerant than other really, really thirsty crops. ("Pumpkin also exhibits a higher economic yield in arid and semi-arid regions compared to other agricultural products such as wheat, barley, and chickpeas.") The Seminole pumpkin looks interesting.

Jane--Thanks for your feedback. That's a good point about those locations being tropical. The terms "desert" and "arid" being used throughout the article were a bit misleading.

Jim--Thanks for sharing your pumpkin growing experience. I think you are probably right and the article may have been...stretching the definition of "drought tolerant". That would also explain why the chilacayote I grew the one time were cute cantaloupe sized fruits rather than watermelon sized ones.

Stephen--Thanks for the information. If one and a half months of hot, arid weather paused the growth of your pumpkins, then it makes sense that pumpkins planted in my location would be paused and not growing most of the year. The weather here typically is a long hot and very dry season followed by a cool season with occasional rain.

"When a person purchases a can of pumpkin, I believe they are purchasing "Delicata"."

Libby uses a proprietary strain of the Dickinson pumpkin variety  which is a Moschata squash for their canned pumpkin.  The same tan skinned, orange flesh family as Seminole, Long Island Cheese, Musquee de Provence, Butternut, etc.

I actually think pumpkins can work. I had a pumpkin from the store I smashed by the front door. It regrew itself a year later and was the happiest plant in my garden that year. I think I watered it maybe twice from July to Sept. It only produced 1 pumpkin but that's mainly due to our short growing time and how late it took to get warm enough for the plant to germinate. I think with a tiny bit of irrigation certain varieities can work but you gotta plan for like desert heirloom kinda varieties. Not like french cinderella pumplin kinda varieties.

unfortuantely I cant experiment with squash this yr b/c I have a terrible squash bug problem and I want to give it at least 1-2 yrs to suppress.

Once they initially catch, a lot of sprawling squash kick out extra rootlets on their vines, and I think that makes them more resilient and productive in dry conditions. And when a rain shower hits -- they go nuts!

Extra water does seem to get the plants to "catch" and produce extra roots along the vines. The chilacayote squash I planted has taken off with the greater than usual amount of rain we have been having in the Southern California/Los Angeles area. I decided that if the vines that were under the covered front porch were the doing best, and the ones that got sun were dying, it might be worth trying to move the whole vine into dappled, almost full shade before summer hits. I wrapped the vines around the corner from my front (south facing) porch to the side yard (east facing) where there are several feet between my house and my neighbor's house. I'm hoping it will root there enough for me to eventually disconnect it from the initial planting spot.

I have a question that might be silly...but I'm curious. Is it possible to graft squash vines that aren't the same group (Cucurbita ficifolia)? I wouldn't mess with it for an annual plant, but since chilacayote can live a few years it might be worth it. It seems like theoretically I could have it getting strong each winter, and then graft something else on the southern end just for the summer so that the chilacayote gets the shade and the grafted variety gets full sun but the benefits of established roots. As far as I know, there's only one Cucurbita ficifolia, but it can form "interspecific hybrids with Cucurbita maxima, Cucurbita moschata, and Cucurbita pepo", at least according to wikipedia. I really have no idea how this works.

It depends on what Maxima variety you grow, there's hundreds, you need to grow the ones adapted to your region and keep adding new genetics. You breed your own drought resistant local variety that way. Joseph Loftouse is on Permies, he does nothing else and sells seeds as well.
I have dryland farmed in a corn field, the farmer wanted to try three sisters, he seeded all together. The seeds came from a farmer far south he had been mixing all kind of dry varieties up. As people mentioned they were of a smaller variety and we had a rainy year. But without watering this was the result from a two acre field i guess. Hé seeded, we harvested before hé tractorchipped his corn plants for cowfodder. It was prématuré.

It's definitely possible. The Hopi and other SW USA tribes raised pumpkins with zero irrigation in 7-10 inches of annual precipitation. https://seedssoilculture.org/newsletter-2019/hopi-tutskwa-permaculture-institute-arizona-us/

Here's a video of Hopi farmer who is raising squash (not pumpkin) in the desert.  

Does anyone know a good source of Hopi or Navajo seeds?

Native Seed SEARCH sells seeds of the desert and Mexico.

https://www.nativeseeds.org/

Seed Treasures at jackieclay2007@yahoo.com,
Sells Hopi Grey squash and other seeds.  She' currently in MN,  by way of the southwest and MT.

You can dry farm pumpkins in San Francisco Bay Area - even in hot places like Marin and Sonoma.  have to choose sites carefully - grow better in wet winter zones - and then heavily mulch. Ideally early ripening things do better with dry farming anything and often some water is used in the first period of transplanting, but not always. I just saw a farm that always dry farms squash and we accidentally had a crop last year after feeding them to our pigs the year before. No watering. But they were in the area that is very wet in the winter and only survived where we had hay mulch (our goat shed bedding put along the fence line) on the ground.

Hi, Lydia. A warm Permies welcome to you! I figured the composition of pumpkin might be of help.:
https://www.universityofcalifornia.edu/news/10-things-you-probably-didnt-know-about-pumpkins#:~:text=Interestingly%2C%20pumpkins%20are%2092%20percent,vegetables%20and%20fruits%20their%20color.
Here you can see #6, that Pumpkin is 92% water, so it has to get it from somewhere. Perhaps, in an arid area, if you can grow your pumpkin an a bucket of rich and well watered soil, you would be ahead. If I had that problem, since pumpkin roots are rather shallow, I'd use a homer bucket [5 gallon] and make holes not in the bottom but about 4-5" up the side of the bucket, insuring that after the first watering, there would always be 4-5" of water in the bucket. You could bury the bucket to the rim and also mulch the plant.
Look also at #9: Native tribes would grow it along river banks. They knew that this plant [all cucurbits, which contain a high percentage of water, really] is water dependent.
The problem that people have in Bangladesh, which is used as an example in the article you quote, is more one of poverty and lack of water suitable for *drinking*.
On Bangladesh Aid America, they specify: https://www.wateraid.org/us/where-we-work/bangladesh
"Bangladesh has an abundance of water, with around 24,000 km of rivers flowing through its fertile land. But providing water safe enough for everyone to drink is a complex national problem".
The article you quote states:" In Bangladesh, mini deserts – known as sand bars – are formed due to climate change-caused flooding during the torrential rains of the five month-long monsoon". In the very next sentence, they specify: "The sediments deposited contain highly toxic elements due to river pollution, and they render the land infertile."
So the problem is not really due to lack of water. Rather, it is a problem of pollution: The water that flows in the rivers ruins the soil. They are now advocating for collection barrels/ / cisterns/ reservoirs that would more than meet the need for multiple crops, thirsty or not. The water falling from the sky is fine, and abundant. After it passes through toxic deposits, however, that water is a lot less suitable, especially for drinking.

Mountain Norcal here. I got some pie pumpkin volunteers this year. I snipped 3 off the vine last night ( bc bears). Definitely smaller than the parents.  I forget which early month they came up on their own, and the 3 i planted later are not going to fruit, vines are much smaller too. I've had to water them everyday to survive the heat in the raised bed they are in.

Will I try them again?  Yeah. Does the raised bed need more fill? Also yes.

A few years ago had some nice success with buttercup squash in a 3sisters set up, the beans didn't do anything and died, but they too were irrigated pretty regular.

None of the pumpkins or other squash I tried in my unirrigated 18" rain a year Bulgarian garden the past two years have survived past seeding stage, but they were seeds from the UK so not locally adapted or local seeds from plants grown in irrigated gardens.

But I noticed on my last visit squash that looked like butternut were being harvested from presumably unirrigated broadacre fields. I'll get a couple of those squash and try the seeds from those next year. They should have more useful genetics. I can also plant them in a semi-shaded spot that gets run-off from the roof if we're blessed with any rare summer rainfall.