Top Tips for growing Physarum Polycephalum...

[Heather Barnett]

If you're keen to grow your own the slime mould Physarum Polycephalum, this information may help...

Preferred conditions: dark and damp (for example: petri dishes or tupperware in a shoe box or similar, with a damp base - paper towels or agar base).

Food likes: favourite food is porridge oats, doesn't mind starchy stuff like rice and pasta. Best to give sterilised (i.e. boiled) food, so it doesn't go mouldy as quickly. I often boil flaked oats to make a paste and keep it in the fridge.

The slime mould itself is harmless, but the food you give it will go mouldy (just usual food mould) so some care is needed, and your pet physarum slime mould should move to a new clean environment on a weekly basis.

Its top speed is approximately one centimetre an hour, so not exactly a spectator sport, but its beautiful growth patterns are clearly visible and easily captured with time lapse photography. My films are shot at various frame rates, from one shot every 20 seconds to one every 5 minutes, depending on what I want to show.

If you want to capture protoplasmic streaming (the inner pulse of Physarum polycephalum which transmits nutrients and chemical signals) chose a frame rate of less than 90 seconds as that is the approximate duration of the pulse in each direction.

Happy growing… do share your results...

[Divya Sengar]

Alright thanks, It's a good thing that I bought the 2 percent agar.

[Jan-Maarten Luursema]

In my experience too, 2% agar works fine. I source it from an Asian supermarket, the kind that has no additives. Not laboratory grade, but by boiling it during preparation you get rid of most of the biological contaminants. For fun I tried flavored/colored agar too, which mostly works fine, although 'true' molds (dust molds as opposed to slime molds?) seem to mess up the candy agar faster. You'll find more about this here.

For time lapses I keep the slime mold container under a hood with led-strip lighting that is always on. A laptop and a webcam attached to a tripod are part of the setup, and I use CandyLabs VideoVelocity software for the time lapses, which gives you great control over light, color, etc. I mostly shoot one frame every fifteen seconds, which at 30 frames per second gives you nice, slow movements with pulsations.

[Steven Paul Wetzel]

Hi Heather,

Do you (or any other collective member) have advice on what to do if P. polycephalum feels like slowly escaping a petri dish? 

[Heather Barnett]

Let it and watch it go! I once had a very impressive cascade of physarum as it gradually moved its way up a pile of petri dishes. It usually means its exhausted nutrients available in the dish and/or the oats are going mouldy and it's time to move house. :)

[Steven Paul Wetzel]

Perhaps it is because I added too much water to the paper towel base to increase physarum's feeding abilities(imagine eating pancakes without syrup).  Adding the extra water increased its speed and mass but my theory is that it stuck a portion of itself outside the dish to evaporate some of that water because now it is back inside (1% is still sticking out). 

I ordered and received my sclerotia last week and grew a piece on Friday.  

Steven.

[Jo Podvin]

Give it somewhere nice to go! I've had lots of escapees--they'll grow just fine in a pyrex dish, or on a wad of wet paper. Let it out to explore! 

[Jan-Maarten Luursema]

If you keep it on a glass plate with an aluminum rim, and fill the plate with agar, it will be reluctant to crawl over the aluminum

[Roger E]

Do I need to do anything special to grow physarum polycephalum in an arid climate?

I just received a pet slime mold for Christmas, but I live at high altitude with very dry air.  Will the agar base in a petri dish provide enough moisture?  Or do I need to arrange some kind of humidity control system?

Also -- this is probably a stupid question, but i can't seem to find the answer:  Is a covered petri dish airtight?  Do I need to keep the cover off?  (Does a slime mold even require oxygen anyways?)

Any advice greatly appreciated!

[Heather Barnett]

Hi Roger,

A petri dish containing agar should hold enough moisture with a lid on (the agar will slowly evaporate without a lid). The container doesn't need to be airtight, most petri dishes allow some movement of air. The organism is aerobic but I don't know if it 'requires' oxygen. I've grown it in airtight containers without any problem, but usually use petri dishes as they're easy. My advice, to all Physarum growers, is to try different methods and observe behaviours - there's no better way to get to know and understand your pet slime mould than empirical experimentation!

Best, Heather

PS: I love the fact that you got your pet slime mould as a Christmas present :) Happy growing...

[Rosie]

great thanks for the top tips.

I currently have mine in a tupperware container with a damp tissue and bits of wood and in a shoe box and in a drawer.

Do you know where to buy agar jelly by any chance?

I also have some that is not moving - is this likely to suggest its dead?

thank you

[Jan-Maarten Luursema]

Agar powder is sold by many Asian supermarkets. Look for plastic sachets like this

I usually use 110 gram water with 2 gram agar powder. Bring to a boil and keep stirring for about two minutes. Let it cool a bit while still stirring, and then pour the agar over your substrate. Good luck!

[Emilie Pugh]

Hi, I'm new to growing slime mound but really excited by the prospect of growing it. I ordered some myxomycetes culture and some oatmeal agar and some Petri dishes. It arrived with no instructions and I'm not sure how to get started.. The culture has arrived in small dried orange rectangles and I'm not sure how to activate it... Do I wet it? Do I place it on a bed of boiled up oatmeal ? How much oatmeal do I put in the dish? Just under the culture or all over the base of the Petri dish? Sorry for all the questions I've tried to find out this information online and no where seems it tell you about this beginning part.. I'd appreciate any tips.