Hardy Passiflora (maypop). Too good to be true?

[Shabou]

Hello All:

Saw this comment from a fruit trees producer in British Columbia, Canada:

…”As far as i know this is the only cold hardy fruiting passion flower. I’ve noticed that this hardiness depends 100% on very well drained soil and proper hardening off…”

Latin Name: Passiflora incarnata
Pollination Requirements: Self-fertile
Propagated by: Cuttings
Soil and Sun Preferences: Half to full sun, very well-drained soil.
Years to Fruiting (average): Several
USDA Hardiness Zone: 5
Hardiness in Celsius: -28.9
Eventual Size: 8 to 12 feet linear

It’s sounds so interesting. I love passion fruit. Should I dive for it? Since my English is not optimal: does the text implies the plant is in-ground or in pot???

Thanks!

Marc

[jeremybyington]

I am in zone 6 and my Maypops died to the ground (as expected) and I am awaiting May to see if they pop. I suppose if you put them in the ground and top them with plenty of mulch over winter they will have a chance in your zone 5. If you are going to do containers don’t bother with passiflora incarnata when you can just bring a passiflora edulis indoors over winter.

[Jujube]

I started growing them last year in zone 6 as well in a partially amended clay soil and only mid to late day sun. Waiting to see if it’ll come up again as it died to the ground, as expected. Flowered in our warm fall last year in year 1

Just fyi each flower only lasts 1 day but smells lovely. Beautiful foliage even without flowers. Slow growing in my first year when planted in late spring and half sun but took off when the summer heat started to calm down.

[JohannsGarden]

I’d love a “self fertile” maypop. I think that nursery description is misinformed though. So far I’ve only got fruit set from cross pollination. Faux fruit don’t count (when they appear to set fruit from self pollination, but turn out to just be hollow shells).

[Shabou]

Thank you both. Your testimonies are precious to me. Marc

[JeremiahT]

The natural range of P. incarnata does extend into parts of USDA Zone 5. With heavy mulching, maybe a good microclimate, I think you could do it in Québec. They are very adaptable plants.

My wild local strain produces tasty fruit in fall. I think it’s actually better than the commercial tropical passion fruit I have tried, though the seeds of the maypops are bigger and crunchier. There’s a lot of variation in the genetics and flavor of maypops, though.

These native ones die back to the ground every winter (Zone 6b, Kentucky), only to return with gusto every spring.

In your cold zone, it might be helpful to remove the mulch in spring—and perhaps do other things to hasten warming of the soil (perhaps a cloche or mini-greenhouse?)—in order to speed things along and ensure some fruit before winter.

I don’t think many maypops are strongly self-fertile, so it might be good insurance to have at least two genetically different plants.

Even if you don’t get much fruit, they’re very pretty flowers, beloved of hummingbirds and bumblebees.

In brief, go for it!

[RedRam]

What johanns said. I’m 5b and I planted a May pop a couple years ago, and it came back last year, way more widespread than I liked. But if you want fruit, you need two genetically distinct plants, is my understanding. It’s not clear to me if May pops are just a general name and propagated by seed, or if they’re clones. If they’re clones you might have trouble finding something else to get fruit with. The one that I grew was definitely not self fertile.

But holy cow did pollinators love it. I’ve never seen so many pollinators on a plant. Japanese beetles too unfortunately. But it spreads underground way too aggressively for my liking, even in zone 5B.

[TrilobaTracker]

Great info here from many folks. Not much to add!
They do need or at least greatly benefit from a genetically different vine for good full fruit set.

[Shabou]

I second that! A lot of priceless info. Thanks to all contributors. Marc

[Chills]

Passiflora lutea is arguably the hardiest member of the species (yes, hardier than incarnata). Problem is that it doesn’t have a particularly showy flower or an edible fruit.

Incarnata is the hardiest passiflora with a showy flower and an edible fruit. The actual plant offered by Brushwood nursery (link below) is from my yard here in Michigan.

Passiflora incarnata

Scott

[Piblarg]

I have a maypop that is not fruiting very well (think 5 or so fruits despite tons of flowers). I think it must be because it’s all the same plant. If I were to plant the seeds from what fruits that would be a pollinizer right? I’m not sure we’re to get maypop seedling I canada.

[Mtncj]

I’ve about 1.5 years into a couple passiflora. Nothing functional yet, but the first came back last year in 6B I’ll find out soone enough what made it into this year, and I’ve added one that will definitly be indoor/outdoor already that I hope will lead me into first fruits.

[jeremybyington]

Any seeds from the fruit will not be a 100% clone of the parent even when self-pollinated, so that will provide enough genetic diversity to increase pollination.

[TrilobaTracker]

Oh that’s cool!
I sent them some cuttings too but have not gotten great reports back on the status.
They have the “large” one from my videos as well as a tasty white seedling.

[urbangardener]

Scott, do you have another maypop for pollination?

Would incarnata and lutea cross-pollinate?

[Rispa]

Have you tried other types of maypop? How does this one compare?

[hobilus]

@JeremiahT

In your cold zone, it might be helpful to remove the mulch in spring—and perhaps do other things to hasten warming of the soil

Hi Marc- I’m trying incarnata out here in SE Vermont thanks to a couple of generous forum members. I was going to put them in a high tunnel, but I’m getting cold feet on that idea and may try the south side of a building instead. I’m thinking about how best to contain it I too.

think fruit ripening is going to be the limiting thing for you and me, not hardiness, especially since it It dies to the ground.

I’m guessing you get a lot more of that powdery white mulch up your way. Down here at my spot, we get lots more sleet and ice, good snow base being a fairly fleeting thing many years.

[JeremiahT]

@Rispa

Have you tried other types of maypop? How does this one compare?

My frame of reference is only these versus store-bought tropical passion fruit. The latter may not have been picked entirely ripe, but the wild maypops here taste a lot better, and I detect none of the “off” flavors that some folks complain about in certain wild maypops—just sweet-tart tropical goodness; and the riper the fruit, the sweeter the flavor. Seeds are bigger/crunchier in the maypops, though. Some people might not like this, but it bothers me not one whit. (I also eat the seeds along with the watermelon! )

I understand that there is a good deal of genetic diversity among P. incarnata populations—so trying different strains would likely be a worthwhile endeavor. I once heard somebody describe a Texas strain that tasted of bubblegum. I’ve never tasted anything like that here—though, of course, it could’ve also been a product of climate or the genetics of the taster.

In any case, there seem to be some pretty good genetics in this part of the country. @Blake, who runs Peaceful Heritage Nursery in Stanford, Kentucky (not far from here), has been doing selection work with Kentucky maypops for the past couple of decades.

Superior Passionfruit Seed Packet – NATURALLY GROWN | Peaceful Heritage Nursery

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There has really not been a lot of selection/breeding work with maypops. Native Americans, of course, cultivated it (we have accounts going back to Captain John Smith) and likely made selections—but any such work has been lost. I do understand that Eric Stafne at Mississippi State is doing some work with P. incarnata at present, as is Raphael Maier in Europe; and I believe both are looking into interspecific hybrids. And as I just mentioned, Blake Cothron is doing some improvement work here in Kentucky. There is also an “open source” breeding/selection project focusing on pure incarnata that might be of interest to some members here:

https://www.experimentalfarmnetwork.org/project/22

My own “work” in this line is just casually puttering about my native hills and my garden, looking for big and tasty (to me!) maypops!

[a_Vivaldi]

This will repeat some of what was said before, but here’s my experience with them:

I don’t know about zone 5 but in general maypop is quite hardy for such a tropical plant. Unlike the other edible passifloras, it’s a herbaceous perennial, so don’t expect anything above ground to persist after first frost.

Assuming it makes it through the winter for you, you should be fine so long as it gets what it wants: sun, warmth, lots of light, warm soil, sunlight, and heat. Maybe that’s redundant but that’s what it likes. In your climate, go full sun and consider black plastic on the ground and maybe a poly tunnel at the start of the season. You’re going to be really tight in terms of growing season if you want fruit, so anything to push the plant along will help. Something sneaky and clever with the fertilizer regimen might help ad well, maybe high N at first and then high P mid summer to push flowing. I don’t know if maypop responds much to fertilizing, but it’s worth a shot. At least two individual plants is a good idea, since self pollination is iffy.

In my climate it can take part shade but it’s not best, and I’m three zones and several hundred miles south of you.

Well drained soil is important, but otherwise it’s not too picky from what I’ve seen. In the wild around here it shows up in disturbed upland sites, often in poor or meh soil. They do sucker a fair bit, but I don’t think they’re hard to control side the vines aren’t woody.

I’ve never had them with the fruit still green. We always waited until they turned yellow and wrinkled, unusually late summer for us and into the fall. They are very good in terms of flavor, at least our wild ones, better than the p. edulis I’ve had (though I admit I’ve never had those straight from the vine). Pretty seedy and a bit of work to eat though, they are basically just wild plants after all.

It has a huge range, so if you can get some from the northern part, they’ll most likely be hardier than the ones from further south.

[Rispa]

Thank you both for the info. I’ve seen some growing on the side of the road here in Houston and my friend said maypop tastes nasty, so I let it be. I’ll have to find some here and maybe order some other varieties to try.