Has anyone planted sechuan pepper? I got two pepper plants from a nursery and they call the Sechuan pepper (Zanthoxylum simulans) female and say you need a male Sansho pepper for peppercorns.
But the Sansho pepper is a different species (Zanthoxylum piperitum) so I’m a bit confused.
Wikipedia and other sources say both plants are dioecious so wouldn’t you need male and female plants of the same species for peppercorns? Or do these two species cross pollinate?
I got a plant of this recently, so wanted to reactivate this thread. The person I got my plant from said the mother plant came from China. The owner of the mother plant only has the single tree, yet it produces seed. The plant that I have was grown from one of those seeds.
Anyone have experience with this plant?
Hi Margaret and Rob,
Here’s something I just found on Bay Flora’s site:
“Szechuan pepper tree seems to be fairly self-fertile, certainly much more so than our sansho trees, which are strictly dioecious. A greater harvest is had by more than one tree, but not always necessary for berry production. Female plants can self-pollenize so this may explain single trees bearing fruit. Our plants are not sexed, so we cannot guarantee any single plant will produce berries”
So… it looks like even though they are dioecious, females don’t necessarily need a pollinizer (although, they’ll fruit better with one). So, probably best to plant a few if they are unsexed. If you want a couple extra Rob, I’d be happy to give you some.
Thanks for that info, it’s helpful and clarifies why the single plant was producing fruit.
To help with pollination, I’d love to have and extra plant or two if you can spare it. Check my profile if you want any of my cuttings as trade. Thanks!
Edited to add: I just realized who I’m replying to. Thanks, Nate 
The Szechuan (Sichuan) pepper does not need pollination from another tree. It is self pollination on the same tree. Not sure if there are male and females flowers etc.
I do not know what kind of Zanthoxylum it is.
I also have only a Szechuan Pepper (Zanthoxylum simulans) with no pollinator. It seems almost every flower set a fruit despite its young age. I have yet to verify if the fruits contain viable seeds or not, but being in the Rutaceae (Citrus family) I wouldn’t be surprised if it can set seeds with or without pollination.
Note: The common name “Szechuan pepper” can apply to multiple Zanthoxylum species, but I believe the one circulating in the United States is Zanthoxylum simulans.
I have both Sansho ( Zanthoxylum piperitum) and Szechuan/Chinese ( Zanthoxylum simulans) pepper, from One green world.
Both trees are grafted so it appears the nursery is working with a known male(s) (Sansho) and known female(s) (Szechuan/Chinese).
I forgot to update. After harvesting the fruits I found them to contain well formed seeds that appear healthy and viable. I’ve planted them and am waiting for them to germinate now. I would assume seedlings grown from a self pollinated specimen would most likely also end up being self fertile so they should be worth growing out.
I believe your seeds could then become male or female plants. They would be variations of the mother plant.
I germinated a bunch of seedlings a couple of years ago from a lone female. About half of them flowered last season and all of them were female. I’m not sure if the males just take longer to flower, or if the seeds only produce females. It does seem odd that I’ve only had female flowers and fruit. Maybe it’s apomictic?
“Female plants can self-pollenize so this may explain single trees bearing fruit. Our plants are not sexed, so we cannot guarantee any single plant will produce berries.”
They are in the same family as Citrus (Rutaceae) so apomixis would seem very probable given how prevalent it is in the related Citrus.
Hey check it out. Apomixis has already been documented in multiple Zanthoxylum species!
I just found a UK article that specifically references Z. simulans (Szechuan pepper) which states that at least as far was what’s available in that country they have only found pistilate flowers which set apomictic seed. This is probably also true for what’s circulating in the US. When observing the flowers on mine I recall seeing pistils, but no pollen and yet I got heavy fruit set with viable seeds.
Great job tracking down this info! That seems to clarify things. I’m guessing that a majority of the remainder of my seedlings will flower this year. If they are all female, I’ll give an update on this thread.
Yes thanks for all the info.
Per wikipedia, “Apomictically produced offspring are genetically identical to the parent plant”
@alliumnate, do you see a bend at the base of the seedling plant? I have this bend at the base of all my purchased sechuan/sansho pepper plants, I’m wonder if it’s due to grafting or just genetic.
If my Sechuan pepper plant was grafted, I’m wondering why since nursery could have easily just allowed the plant to clone itself via asexual reproduction. Maybe the grafted rootstock some other hardier Zanthoxylum altogether?
@JohannsGarden , do you know if some Sechuan pepper plants that produce pollen exists in the world? Or is it that simply because all known Sechuan pepper plants and seeds are sourced from clonal asexual female reproduction, we have no ability to obtain a male from seeds of the female.
I didn’t look at any studies from their native so I’m not sure what information is documented for wild forms. I have noticed that a lot of plant material gets shared between the UK and the US though so it’s very possible it’s the same genetic material on both sides of the pond for at least those countries.
From reading it sounds like most nurseries are propagating it from cuttings so the bend should be from the new trunk emerging from a bud near the top of the original cutting. I suspect none of the commercial propagators have reviewed the info which would inform them the plants are apomictic…
Additionally I found a reference stating there aren’t any known hybrids between Zanthoxylum species so that seems to hint they don’t cross easily. If that is the case, everyone who also bought a Sancho pepper to pollinate their Szechuan pepper got duped as they likely provide zero pollination benefit.
I have both Sansho and Sechuan, and I’m planning to plant them closeby so we’ll see. Looks like the thorns/leaf/smell are unique feature to the sansho and sechuan, we can check if seedlings exhibit some sort of hybrid appearance. If pollination is successful, I expect a group of offspring to show variability. E.g. Some has sansho thorns, but sechuan leaves, or some leaf/thorn form in between.
