I have some flower heads on some (purported) P. aquatica. What would be the best way (and time) to collect the seeds without letting them self-seed? How do I tell they're mature?

Another question is, how long does it take for alkaloid production to respond to nitrogen feeding? Let's say I fed them today, if I collect the blades tomorrow will they have a higher alkaloid content, or do I need to feed them every day for n days?

The seed heads should be dry when you harvest.
Sometimes mold or bugs will get inside of these so can't harvest.
Just take a seedhead, squeeze it/shake it to see if any seeds inside.
Viable seeds will be dark/beige.

I am posting a picture of Phalaris Aquatica in anthesis and P. Aquatica when seeds are ready.

Thanks. Do you have an idea of roughly how long it takes for the seeds to mature? As in closer to a few days or closer to a couple of months?

I plan to collect some seeds soon with little zip bags i want to put around the seedheads.
There is no danger of loosing the seeds with this method. but it might be more dangerous to get mold or similar problems inside the zip bag. Anyone have experience with this?

One could also use bigger bags and put several heads inside one bag.

Jagube, the seeds take a few weeks to form from when the floret is green turning to straw-color.

Grollum the plastic-bag idea is a common and efficient method for collecting grass seed.
You could also browse around the patches inspecting the seed-heads for signs
of mold(which are usually black patches here and there) and cut the seedhead down
with scissors and put into a bag.
I have Phalaris seedheads from 5 and 6 years ago from different locations that
still germinate and never molded.
Right now: Mid-June to July is when Phalaris will be producing rapid amounts of seeds.
The grass will go dormant until about September, then you can begin harvesting
for alkaloids when the rain returns followed by a dry period.

OK cool. Good to know. Do you think it is possible to cut the heads when they are still a bit green and then let dry afterwards?

@jagube sorry for entering your thread but this might be of interest for you, too, so i ask it here.

My brachystachys is putting up seedheads and there are tiny little things coming out of those still green heads. Is that pollen or seeds already? When I collect those parts with the finger, they look to small and seem to not have a hard shells...

Any ideas on that? I tried to find Information about the process but couldnt find any...

Edit: I found the following picture which seems to describe what I asked for...

Tried this once, with my P. Arundinaceas...was a hell of a work.

The next day, there were torn plastic bags all over the garden...

...and I had to realize that this doesn't work if you have a dog...

Instead of plastic bags wrap the heads with something like cloth tea bags, cheesecloth, or nylon stockings and tie them on with some string. This will allow airflow and prevent mold issues.

For the nitrogen feeding cut the grass back, fertilize, then come back in 7-14 days and harvest the regrowth.

Thanks grollum, a good call.

I'm getting those soft yellow things coming out of my aquatica seed heads and I thought they were seeds, now having seen your picture I'm thinking they're anthers?

I think so. I am asking myself if there is some need to help the plants cross pollinating, bringing the anthers to the other plants. I went for a good weed tousle of the plants in hope of spreading the different anthers between the plants.

Not sure if they are able to self pollinate.

A quick google reveals that the annual Phalaris spp. (e.g. brachystachys) are generally self-pollinating. P. arundinacea, on the other hand, is self-sterile. Haven't found info on P. aquatica.

But come to think of it, my aquaticas are all clones (allegedly AQ1). So if they're self-sterile, I won't be able to get seeds, because all my plants are genetically identical. Which would be a good thing for preserving the traits, but wouldn't allow me to share the seeds (I know that if they did produce mature seed, the offspring wouldn't be AQ1 anymore).

Edit: My plants are clones from the two rhizomes I got sent to me, so if the two rhizomes were clones, all my plants are genetically identical indeed.

Can anyone tell me if he successfully extracted dmt from Phalaris Aquatica in steam current?