So I've been thinking about this a bit. The rates at which our crops grow to harvest are weird. I've been effected by the random bug that is preventing some trees and crops to mature, but presumably that will be fixed soon. (This doesn't seem to happen to me in singleplayer, only on a server.)
In survival mode as we all know it's way too easy. Food grows too fast; trees grow way faster than realism. To a degree, it needs to be faster than real life, of course. And, you can make it more realistic (and difficult) by increasing the hours in a game day. You can go from: 10 minutes = 1 day, up to: 24 hours = 1 day. So, you could go all the way to the slowest speed and make things grow much slower. I see in settings too that there is a slider for plant growth—I've never used it but I might! Though, I also assume that your calorie needs would slow down accordingly—or maybe not? It currently takes only 6 carrots a day to survive. I don't know about you, but that would be torture for me!
But more important than the time needed overall, is the time for a plant to mature in relation to the other plants/trees. Now, a carrot and birch tree take roughly the same amount of time to mature. I am presuming that there is a time increment assigned to each plant for when it changes stages, and that it is different for each plant. This must be the case, unless I am wrong, because Spruce and Birch seem to change stages at different rates. (Anecdotally. I haven't tested.) If this assumption is true, I hope that better, more realistic times (growth rates) can be programmed. This will probably be easier to rationalize with the vegetable crops as they mature in single season, but trees can take 10 to 50 years! (Lumber companies have super-fast growing varieties that take 10–15 years!) Patience in forestry is a must.
Example to-harvest comparisons: (All days to harvest vary widely by location, so they could be biome dependent too! Though probably too difficult to program.)
Corn 100 days
Tomato 95 days
Carrot 85 days
Lettuce 14–60 days (leaf or heads)
Watermelon 75 days
Pumpkin 110 days
Spruce 20–30 YEARS (grow 2-3 feet per year)
Birch 10–15 years
Hickory 15–30 years
Beech Willow 15–20 years
London Plane 15–30 years
If we want fast growing building material we need Bamboo! Bamboo can grow up to 3 feet in a single day!! Seriously. LOL.
If we were really surviving we'd need to be much more conservative in cutting trees, and probably build more from stone or mud. We'd also have to forage more to supplement food while waiting for stuff to grow. So maybe tree growth times could be a LOT longer than vegetable growth times. Or you could have a selection for that. Forage plants could be made more or less scarce the way that Ores currently are. (It does seem like they are slightly less common in Unity than they were in Java.)
I figured that having the days to maturity for veg, and growth rates for trees all in one spreadsheet might be handy, so geek that I am I collected some. Attached. These have all the veg we have plus more, and most of the trees I could remember. It has the rates of growth to harvest, (as product or wood) and I also included storage times under proper conditions. As I know food spoilage will eventually become an issue. This varies by type of product and by the method of storage and preservation.
Let's also mention food types! No subsistence farmer could live without a grain crop either Wheat, Rice, Barley, or Oats. Corn is a grain (sort of) but it's not used exactly the same. But American Indians all survived for eons on Corn, Squash, and Beans. We must have beans!!! Nuts from trees are a very important forage food source too. I know, all good things in time.
True survival means you must hunt for protein and WAIT for your farm crops.
Anyway my 2¢ on farming and forestry. Animal husbandry next!! (Yes, I have opinions. LOL)
Looking forward to the update!