I was able to grow these in southern Ontario. They overwintered the 2022-2023 winter in Oakville (zone 6), but they were too late to send new shoots in the spring (late June), so they flowered a lot in 2022, but not in 2023. That’s the in-ground plant…
I also took cuttings in fall 2022, and used them to grow a couple clones in containers. Cuttings flowered earlier in 2023 (mid July) than the in-ground plant did in 2022 (early August), and was able to begin setting fruit in mid-late August 2023. I believe they are not self-fertile, so they were most likely fertilized by my passiflora caerulea. I had to take the plants indoors in November to protect them from frost, and for the fruits to finish ripening, which they did, and produced viable seeds (some of which have already sprouted).
For the winter 2023-2024, I brought them inside. One plant died, maybe I brought it inside too late, or didn’t provide it enough light in the basement (just had a grow light). But the plant I kept in a south facing window is still alive, and began sprouting new shoots from the ground, one of which has been flowering for the past couple weeks. It seems to take about 2 months from new shoot to flowers, and 2-3 months from flowers to fruit, with maybe an extra month needed because the first flowers might not set fruit? That means you want 5-6 months of summer weather, when southern Ontario/Quebec has closer to 4-4.5. Hence why you should have them in containers (or a greenhouse) to either give them a head start in the spring, or to extend the season in the fall.
I’m also trying out edulis (purple passionfruit), ligularis (sweet granadilla) and tripartita (banana passionfruit) in containers. They’re a little over a year old now, so hopefully 2024 will be the season that they first flower (and hopefully even fruit)?
I think cuttings produce fruit sooner than plants from seeds by the way - just something to keep in mind. My passiflora caerulea grown from seed only gave 3 flowers from 3 plants on its first year, whereas my passiflora caerulea grown from cuttings gave me about 100 flowers per plant on their first year.
Passiflora Capsularis flowers for me from seen in one season. Mine is in a pot and I bring it inside each winter.
Flowers are small, white and smell sweet. The fruit isn’t considered edible and the fruits explode when ripe (which means I get seedlings in surrounding pots frequently).
If I have time—and have some decent fruit. My native maypops have largely stymied my efforts at cultivating them. The problem is that they do not come back in the same spot every year. If they would even come up near the original crown it would be okay—but often the new spring growth is composed of suckers coming up a considerable distance from the original plant, sometimes 10’ or more away. It seems pointless providing permanent support.
In the meantime, if you are interested in good Kentucky maypop genetics, I recommend:
After this past winter I can officially say that all of my P. incarnata (and hybrids thereof) failed to overwinter. The local climate zone doesn’t seem to mean much regarding what will survive here. We almost always get our worst cold snap of the winter after a period of spring like warmth. I regularly lose plants that are rated to much colder climate zones…
Just a quick question about your maypops. Have you tried planting them in a large, buried pot (kind of like what people do with mint, or bamboo?) I am about to put some in (zone 6a), but am feeling a bit leery about the potential for uncontrolled spread…
No, have not tried that. I wouldn’t worry overmuch about just planting them in the ground, though. The suckers are easily pulled or mowed; and they don’t grow rankly as do bamboo and mint. They pop up in my blueberry and gooseberry area all the time. I just pull them when I see them where unwanted, and no harm is done. I let some grow and fruit on my big Pixwell bush last year—perhaps not best horticultural practice, but good enough for me!
I tried incarnata on the Oregon coast, and they eventually died on me. I remember reading somewhere that they can handle cold OR moist, but not too much of both at the same time. I think it probably depends on cultivars or origin of seeds, so I may try again.
They do better in well-drained soil, yes. This is true in all seasons, but especially true in winter when they’re not actively growing.
That being said, given how many people report failure with maypops in the PNW, I’d have a hard time believing none of them have well-drained soil. In the PNW, it’s a double whammy of low summer heat and sun, so weaker plants, and longer cold spells during the winter. You and I are fairly close to the same zone, and yet despite my lows being a little lower, I’d bet money that your ground freezes more than mine does.
I think this is the number one factor… what little energy they can store over the brief growing season is barely enough to keep them alive through the very long dormancy. My seedlings were largest at the end of their first year, smaller at the end of year 2, and still haven’t emerged this year, if they even still will (I’m doubtful).
Plus, even during the growing season, the overnight low is often in the low 50s or even upper 40s, so they grow less vigorously even in the middle of summer, compared to places with warmer overnight lows in summer.
I think you and @a_Vivaldi and @JohannsGarden are hitting all the reasons. We have constant summer sun 15 miles inland in Southern Oregon, and only a dozen or so of days per year below freezing in the winter, but cool nights and low humidity in the summer, so the maypops just languish. Lots of warm season vegetables like most varieties of eggplants, sweet potatoes, and melons also fail to thrive, so it makes sense maypops are a challenge.
Spoke too soon, one of my third year seedlings is finally starting to emerge. I’m going to try to keep it watered more this summer in the hope it’ll grow better than the last couple summers.
I’ve only eaten a couple but I agree with @a_Vivaldi maypops here when green are very dry inside and sour. He’s responsible for me growing these tetraploid also haha
Unnamed tetraploid seedling and purple passionfruit planted together
Where did you get your unamed tetraploid? I just got marjorie sherwin from passiflorista on ebay. I also have incense, fata confetto, and some maypops but haven’t had fruit from any of them yet.
