Thistles are grown in a Thistle Garden.
One seed per planting is used. The growing period is 40 ticks of about 6 seconds each during which the various reactions occur. Thistles take roughly 4 minutes per batch to grow. The yield is 5 thistles of varying attributes (ex. Thistle:A-B~C+F~N-P+T~)and 2 seeds. Aborting the process early yields no thistles or seeds.
The three symbols used to represent vitamins levels are:
| - | Low | < 22 |
| ~ | Average | >= 22, < 80 |
| + | High | >= 80 |
Note that vitamin levels appear to be real numbers, even though they are displayed as integers. Sometimes a level of 80 will be considered average rather than high, presumably when it was rounded up from 79.9.
Water, Dung, and Saltpeter are used to change the levels of H20, Nit, and Pot respectively.
One resource is used each time you click on the nutrient. (So one Dung per Nit click.)
Thistle Gardens provide the following information on thistles by selecting "Info: Read about Thistle Gardens" from the menu.
The readout shows five nutrients. You can adjust these directly by pushing the appropriate button. They are:
The readout also shows seven vitamins:
As it grows, the thistle converts nitrogen or potassium into vitamins, and it converts vitamins into other vitamins. For example:
It will take experimentation to learn all the things that thistle can convert. Once you know what it can convert, and under what conditions, you can encourage it to produce the vitamins you need.
Thistle is affected by day-to-day weather variation. On certain days, thistle just won't do certain conversions. Each morning, you will have to test the thistle to see which conversions it will do, and make your plans accordingly. Active conversions change at Midnight.
Modern Sheep Pens require 2 randomly chosen specific Vitamins, but they seem to only require an Average "~" amount of each of the two vitamins. So if the your sheep are craving Asc and Bio, only 40 of each vitamin are actually needed when growing the thistles. The levels of the other vitamins do not seem to matter.
The Modern Sheep Pen research at the University requires High "+" amount of one specific vitamin. The levels of the other vitamins do not seem to matter.
Silkworms require specific amounts of 4 different vitamins in the same thistle such as: A~B~C+N~
You may find useful thistle methods on the Thistle Recipe Page.
If you can grow thistles, please check out the Thistle Requests.
No Asc at night The reactions which produce and remove Asc only function at high sun, so don't try for anything requiring A~ or A+ at night.
You can't get rid of Bio There are no conversions in which Bio is reduced. If you need B- then you have to avoid producing it in the first place (often difficult)
More reactions during the day Due to the extra reactions active at high sun, prediction and control of vitamin levels is alot harder than at night. The corollary is that a wider variety of thistles is possible during the day.
The other key feature of the conversion set is that it contains several cycles which, when active, produce vitamins 'for free':
Thi<->Car At low oxy, 1 Car produces 2 Thi and 1 Bio. At low water, 1 Thi produces 2 Car and 2 Fol. So when both are low, you will often observe Car and Thi static at 10 and 20 respectively, while Bio and Fol increase, apparently from nowhere. If the Car->Bio conversion is inactive, Car will rise instead. Likewise Thi will rise if the Thi->Fol conversion is inactive. These conversions are very sensitive to water and oxy level, and careful cycling of these values between 30 and 50 can be used to manually raise Car or Thi. To enter the Thi-Car cycle it is necessary to produce at least 13 (to be safe) of one or the other.
Fol-Pyr-Nia-Fol At low sun, this is a useful circuit to be aware of as you can shift vitamin to any one of the 3 and hold it there. 1 Fol-> 2 Pyr works at high oxy, 2 Pyr-> 1 Nia works when water >50 and 1 Nia-> 3 Fol when water <50. There is therefore a net gain if you go all the way round, though it takes time.
Thi<->Nia An elusive beast. I'm not sure of the exact conversions between these 2, but they are there, and they make raising Thi at night very hard. The conversions in the table below are a guess at best. Further study needed.
| Water | Oxygen | Sun | Uptake |
| any | any | low | 10 Pot -> 2.5 Bio |
| low | any | low | 10 Nit -> 2.5 Pyr |
| any | high | any | 10 Pot -> 3.3 Car |
| high | any | low | 10 Nit -> 3.3 Thi Often appears as 6 Nia due to Thi -> Nia below |
| high | high | high | 10 Pot -> 3 Pyr |
| high | high | high | 10 Nit -> 3 Pyr |
| high | any | high | 10 Nit -> 3 Asc |
| Water | Oxygen | Sun | Conversions |
| >50 | any | low | 10 Pyr -> 5 Nia |
| <50 | any | low | 10 Nia -> 30 Fol |
| any | high | low | 10 Fol -> 20 Pyr |
| any | >90 | low | 10 Pyr -> 10 Bio |
| low | >80 | any | 10 Car -> 20 Thi 10 Thi -> 20 Car 10 Car -> 10 Bio |
| >50? (high) | none | low | 10 Thi -> 20 Nia |
| low | any? | low | 10 Nia -> 5 Thi |
| low | any | low | 5 Thi -> 10 Fol |
| >50 | any | high | 10 Nia -> 20 Pyr |
| low | low | high | 2 Fol -> 10 Bio |
| low | low | 99 | ? Asc -> 20 Bio ? Asc -> 10 Pyr 10 Nia -> 5 Thi |
| high | high | 99 | 10 Car -> 10 Pyr 10 Pyr -> 5 Nia |
Some conversions may have fine differences in what's considered low (<40 or <30), but it isn't clear.