Can you bury passionflower trunk?

[NickD]

I'm growing passionflowers in containers, and the soil level has been dropping. I guess the compost in the soil has been breaking down. My 5-6 gal pots now have a soil line that's about 3-4" below the rim of the containers, so I want to add 2-3" of soil to bring it to within 1" of the rim to make full use of the size of the container.

Is it okay to bury the stem/trunk of the vines like that? I know for young plants/thinner vines it's fine and they'll just grow new roots from the buried part, but I was wondering if it's still okay for thicker woodier growth that's about 1/2" to 3/4" thick. Also, some of these vines are starting to branch out from the trunk very close to the ground level, so there would be some nodes for thicker secondary vines that get buried too.

It seems like I might have to repeat the process on a regular basis, once or twice per season, due to the fact that the soil had a lot of organic matter in it.

Species I'm growing in containers include

incarnata
caerulea
manicata
tripartita (var azuayensis)
edulis
ligularis

[xesoteryc]

Dont. You will kill the plant like I did with my first vine, on top of not having good enough drainage.

[NickD]

Dont. You will kill the plant like I did with my first vine, on top of not having good enough drainage.

I guess I can try to ease the plants out of the containers and add soil to the bottom or up-pot. Maybe add mulch for the plants that I want to wait until the end of the 2024 season to do that for (mulch should let enough air in not to harm the trunk while keeping the moisture closer to the surface of the soil, encourage roots to make use of the near-surface).

Why would drainage be an issue though?

[vnomonee]

the older trunks are susceptible to fungus. are you able to lift the plant out of the pot? if the roots are substantial the whole plant root system should pop out with the soil. then you can add soil to the pot. i have a short video of what the root system looks like on a 3 gallon plant https://www.youtube.com/shorts/LeF0tpc2Vbw notice the entire rootball came out with barely any soil visible

[xesoteryc]

Dont. You will kill the plant like I did with my first vine, on top of not having good enough drainage.

I guess I can try to ease the plants out of the containers and add soil to the bottom or up-pot. Maybe add mulch for the plants that I want to wait until the end of the 2024 season to do that for (mulch should let enough air in not to harm the trunk while keeping the moisture closer to the surface of the soil, encourage roots to make use of the near-surface).

Why would drainage be an issue though?

It loves to breathe

[Tropicaltoba]

I ended up cracking the base of a 5yo vine in a large pot they get very brittle. It looked intact but u could see the vine just dry up.

I currently have 2 purple in 35 gallon pots 3 and 1 yo. Looks like I may get 75 fruits this spring. I am curious about what is the max number you could grow in a large container? I staring doing proper pruning (not perfect) this year and it made a difference.

[NickD]

the older trunks are susceptible to fungus. are you able to lift the plant out of the pot? if the roots are substantial the whole plant root system should pop out with the soil. then you can add soil to the pot. i have a short video of what the root system looks like on a 3 gallon plant https://www.youtube.com/shorts/LeF0tpc2Vbw notice the entire rootball came out with barely any soil visible

The soil is kind of heavy so I'd be worried about snapping the trunk or roots if I started pulling on it, but once it's warm enough to bring them outside (mid-May), I can try and hold the containers upside down and see if the root ball can slide out.

[NickD]

I ended up cracking the base of a 5yo vine in a large pot they get very brittle. It looked intact but u could see the vine just dry up.

I currently have 2 purple in 35 gallon pots 3 and 1 yo. Looks like I may get 75 fruits this spring. I am curious about what is the max number you could grow in a large container? I staring doing proper pruning (not perfect) this year and it made a difference.

My maypop had about 20 fruits on its first year in a 5gal pot, although I accidentally snapped a large chunk of vine when I tried moving it inside to finish ripening after the frost, so only 8 of them actually ended up ripening. In a larger container, with a more mature plant, and a longer growing season, I would think you could get quite a lot.