Wisconsin Fast Plants Network

To know a plant, grow a plant!

Over the course of 25+ years, many different growing and lighting systems have been developed for Fast Plants. The question of which growing and lighting systems to use became complex enough that we actually hired custom programming for our website during its last revision to help guide educators and researchers who are new to growing Fast Plants through the decision-making process.


Still, there are many effective growing systems that are not included in our website (or the information about them is buried in the vast archives that live there). KSBioteacher's latest blogumentary about making his version of the portion-control-cup/deli-container growing systems is just one example of a great alternative to the bottle growing system that is found more prominently on our websites (fastplants.org and bottlebiology.org).


The decision about which growing or lighting system to use boils down to a combination of your purpose for the plants (e.g. being able to separate individual plants at some point vs it being okay to work with a group of 4-6 plants growing together in a system, or if you're quantifying soil volume, or limiting nutrients, etc.), the amount of space you have for growing and setting up your light systems, materials availability / budget, and personal preference.


Yesterday, I received the following question about why a wicking system is recommended:

I have a general question about how to grow these plants.  I read in the instructions that I have to use some kind of growing system with a wick.  Is that just to keep the soil really moist and so that when watering the plants, you don't disturb the seeds?  Is it possible to just use the standard 3 x 4 in plastic pot with holes on the bottom and have the pots sit in a tray filled with a bit of water?
My response follows. Please feel free to add recommendations and comments that may help this first-time grower.
You are right about the role of the growing system with wick being used to minimize seed disturbance and keep the soil moist. Your suggested method will work if you carefully regulate the depth of the water such that the roots also have ample oxygen. If the soilless mix becomes saturated with water, then the roots will drown. Also, when the plants go into the flowering stage, they will drink a lot of water, so you'll need to monitor water levels extra during that time.

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Another good question came up recently about using peat pellets to grow Fast Plants. We've used peat pellets in the past successfully; they fit really nicely into a portion cup growing system (aka Discovery Cup System) such as the systems that Brad carefully documented making here and Paul describes in his sandbox entry here.

When we've used peat pellets--either for growing mosses or Fast Plants--we've pre-soaked the pellets in water. Then, when the pellets were fully expanded, we used small, sharp scissors to snip the webbing that holds them together around the pellet's "waist" so that every pellet made soil for two Discovery Cups. The pellets fit perfectly into the portion cups. We placed each half-pellet in a cup, "waist" side up, so the entire surface was exposed for planting (no webbing edge anymore). You wouldn't have to do this step for growing Fast Plants because the volume of soil would be fine to use as is when the pellet is whole, but you could. When we were using the peat pellets, we were making tiny moss gardens that were contained within the portion cup (lid on), so we needed less medium in the cup to make room for the mosses.

Any other members of our network who have used peat pellets with Fast Plants could share insights into how the system worked for them. I don't recall that we did anything special to get the wicking system to work--I believe the wick just had to be in contact with the peat pellet (in the moss gardens we don't use a wick). You'd just need to be sure that there is good contact between the peat pellet and the wick and that everything is thoroughly soaked (wick, too).

Alternatively, the flats that peat pellets are sometimes sold with could be modified to work, I'm sure, or other growing systems could be designed to use the pellets. It's just a matter of making a growing system that will both grow Fast Plants well and effectively allow students to pick up their plant(s) and make observations. The portion cups (sometimes sold as "shot glasses") are perfectly sized for the peat pellets and pretty easy to nest in a recycled deli container so that groups of four students can share one deli container that houses their four plants. Some teachers have reported getting portion control ups donated for their use by local restaurants; we purchase ours online.

To plant in a peat pellet, place 2-3 Fast Plants seeds on the surface of the fully moistened peat pellet and lightly cover with either a sprinkle of soil-less planting mix or vermiculite. Then, top water lightly so everything is moist.

Please add comments if you've used peat pellets for growing Fast Plants--we'd love to learn from your experiences!

Thanks for the details Hedi!  What I would like to do (plan to do) is use the Jiffy Greenhouse systems I already have.  I've purchased a number of fast plant mutants that I plan to mix together and provide students for planting.  My idea is to ensure a variety of observable variation for selective breading.  Each group of 3-4 will have their own greenhouse, and so will be able to grow a large population of plants.  I'm glad to know that the pellets can be split.  That way each group can use the supplied pellets for both their diverse parent population followed by their F1 offspring.  Since the pellets are self-wicking, I would like to not have to use a additional wick.  I understand that this will require close monitoring of the water level in the system.  The greenhouse instructions call for fertilizer to be added only to the water initially added to the tray.  Does this sound like the way to go with fast plants?

You can definitely add the fertilizer to the water. We use Peter's (now called Jack's) fertilizer as described on our website and pasted below. Sounds like your students will have plenty of different traits to select from for a breeding program; I hope you have time to keep us posted!

Peters Professional™ Fertilizer
Peter's liquid fertilizer solution provides nitrogen, phosphorus, and potassium plus some trace elements to plants. Make a stock solution of Peters™ by dissolving one level soda-bottle capful (7cc) of Peter's crystals into one liter of water. This stock solution is considered "full strength" and can be applied in two ways:

  • Soil application:
    Apply 2 ml of the stock solution to the soil surface on Days 3, 7, 14, 21, and 28 for each plant that will be grown to maturity.
  • Water reservoir application:
    Dilute the Peters stock solution by 1 part Peters to 7 parts water to reach a 1/8 strength nutrient solution. Keep the reservoir filled with this 1/8 strength solution throughout the life cycle.

I've got it all setup and plan to have students planting this Tuesday.  I had some hydroponic liquid nutrients already that I plan to give a try.  I think the brand is Hydrogrow (I'm not at school).  It's a 7-7-7 fertilizer and I'm mixing it according to the instructions on the bottle, 1.3 ml/L.  At this low concentration, I don't think it will be too much, and since the Jiffy pellets are just peat, I don't expect they supply much in the way of nutrients.  Admitedly, I don't have much of a green thumb and haven't had much luck growing plants in the past.  Wish us luck!

Definitely sending a little green thumb energy your way, James! Hope all went well on planting day, and we look forward to hearing more as your project progresses...

I had 4 teams of 2 students, each with their own Jiffy Greenhouse.  One team had almost all 72 germinate within 2 days of planting, while the others had variable success.  After planting more seeds in the wells that didn't germinate, all groups have a pretty good crop coming up.  Some of the taller plants are falling over, but once laying down they're still turning up to the light and growing.  Should we be staking them?  With the variety of mutants I bought, they have plenty of variation to observe and record.  So far so good!

Sorry I didn't see your post earlier. You can certainly stake the plants that are falling over to help. I wonder if those are the "tall plant" variety, perhaps? Sounds like all is going well. Would be fun to see some pictures if you're able to snap some.

The team with the best growing plants were able to cross pollinate today.  Two of the other teams aren't far behind, but one crop has almost totally failed due to a number of mistakes.  I'm simply going to have that team cross pollinate plants grown by other teams, but not selected by them for breeding (leftovers).  I didn't have them stake the tall ones.  They're doing fine laying down.  I'm anxious to see if they successfully harvest viable seeds!  I'll try to get some pics and post them if they're any good.

Nicely done! 

We have some solid information about finishing your seeds and harvesting at the right time for them to be viable here: http://fastplants.org/how_to_grow/seeds_harvesting.php

Let us know if you have any questions along the way.




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