How does Speed-Gro mathematically work?

[Party You]

So I am on Summer 26 of year 1, and I learned a day late that deluxe speed-gro is sold at the desert for 80g each on Thursdays. it is currently Friday and I unfortunately am too late to close my game and reset the day. I want to buy them next Thursday and put the Speed-Gro on my (probably) cranberries. The only problem is I am not sure how speed-gro exactly works, because if it subtracts a flat amount of days off the total growth cycle then it would function how I want it to and work with my berries. But I am unsure of how they work in terms of the math done.

[Guts]

It does what it says. The time to grow a crop is reduced by 10%. But it only works on 1 cycle of crops, so cranberries won't keep producing faster for each harvest.

I might have the numbers wrong, but for example if it takes 14 days to grow a cranberry plant, then with speed gro it would take 1.4 days less. If you use it on a grown cranberry plant (assuming the time it takes is 4 days) then it would be harvestable again 0.4 days faster.

Deluxe speed gro works the same but with a 25% effect.

[I Kinda Fail]

Ursprünglich geschrieben von N473:

It does what it says. The time to grow a crop is reduced by 10%. But it only works on 1 cycle of crops, so cranberries won't keep producing faster for each harvest.

I might have the numbers wrong, but for example if it takes 14 days to grow a cranberry plant, then with speed gro it would take 1.4 days less. If you use it on a grown cranberry plant (assuming the time it takes is 4 days) then it would be harvestable again 0.4 days faster.

Deluxe speed gro works the same but with a 25% effect.

I think they mean like, if it takes 14 days to grow, but you add it on day 6, will it subtract the 1.4 days, or will it subtract 0.8 days?

[Adeptguy]

Ursprünglich geschrieben von Party You:

So I am on Summer 26 of year 1, and I learned a day late that deluxe speed-gro is sold at the desert for 80g each on Thursdays. it is currently Friday and I unfortunately am too late to close my game and reset the day. I want to buy them next Thursday and put the Speed-Gro on my (probably) cranberries. The only problem is I am not sure how speed-gro exactly works, because if it subtracts a flat amount of days off the total growth cycle then it would function how I want it to and work with my berries. But I am unsure of how they work in terms of the math done.

I suggest going to https://stardewcommunitywiki.com/Cranberries
Especially the part where the growth is compared with the fertilizers. Do note it only works on the growing part of the plant, that happens only once. After that you get regrow days of the berries themself, any speed growth fertilizer does not affect regrow days. Only the inital stage of the plant itself.

For example you can see on the wiki growth picture that the plant grows 7 days after planting (I always count it with +1 day cuz I count the seeding day as well, makes it way easier for planning personally speaking, so in this case I'd count it as 8 days and not 7) and after that you get 5 harvests if you did it all on the first day. With 10% speed grow it will finish 1 day sooner and with 25% 2 days sooner. If you got the grow perk then you need to look at the other pics but generally speaking if you dont have the perk then this holds true.

So according to your situation if you want to buy fertilizer at fall 4 and also want to plant the cranberries at fall 4 then you will get 4 harvests for the season. Honestly I wouldnt do it if I were you since once again the regrowth days are not affected and only the base growtime of the plant is. If you just plant all the cranberries you want immediately on fall 1 without any growth fertilizers you will still get all 5 harvests, compared to fall 4 with only 4 harvests.

Not sure if this sounds complicated but im sure you will figure it out once you look at the wiki! Very handy website. And if you dont want to spoil yourself with all the additional information well... Try to not look at it and ignore it I guess xD (I tried it too so yea)

I always use the pics on every crop when im planning my next season, on what to fertilize and what not. Saves me some math, pics are easy to look at :)

[Party You]

Ursprünglich geschrieben von I Kinda Fail:

Ursprünglich geschrieben von N473:

It does what it says. The time to grow a crop is reduced by 10%. But it only works on 1 cycle of crops, so cranberries won't keep producing faster for each harvest.

I might have the numbers wrong, but for example if it takes 14 days to grow a cranberry plant, then with speed gro it would take 1.4 days less. If you use it on a grown cranberry plant (assuming the time it takes is 4 days) then it would be harvestable again 0.4 days faster.

Deluxe speed gro works the same but with a 25% effect.

I think they mean like, if it takes 14 days to grow, but you add it on day 6, will it subtract the 1.4 days, or will it subtract 0.8 days?

Yep! Had a hard time wording it but this is what I mean, because I plan on planting the berries at Fall 1, but putting the fertilizer in on Fall 4.

[iwao]

Ursprünglich geschrieben von N473:

It does what it says. The time to grow a crop is reduced by 10%. But it only works on 1 cycle of crops, so cranberries won't keep producing faster for each harvest.

I might have the numbers wrong, but for example if it takes 14 days to grow a cranberry plant, then with speed gro it would take 1.4 days less. If you use it on a grown cranberry plant (assuming the time it takes is 4 days) then it would be harvestable again 0.4 days faster.

Deluxe speed gro works the same but with a 25% effect.

I wanted to automate the math in a spreadsheet, so i needed the exact formula - i came up with 2 possible formulas (including yours), but none of them seems to work on the Sweet gem berry.

https://stardewvalleywiki.com/Sweet_Gem_Berry states that the deluxe speedgro makes the berry grow in 19 days, and the hyper speedgro in 16 days.

- Growth time reduction by substraction (your method): the berry should take 24-0.25*24=18 days to grow with deluxe speedgro, but wiki says 19. The formula works fine for normal and hyper speedgro though.
- Growth time reduction by division : growth time would be calculated by dividing the normal time by 1+[percentage of reduction] - if this rule is used, the berry would take 24/1.33 days with hyper speedgro, which is approximately 18, but wiki says 16 instead. The formula works fine for normal and deluxe speedgro though.

So in conclusion, i still do not know which formula is the correct one. However, I haven't counted the growth time in-game : maybe the wiki states a wrong value? If anyone has an answer to this, i'd be glad to hear it.

[carl8000]

I'm sure he's figured it out over the past few months, but the scenario TC wants isn't possible since you can't add fertilizer days after you plant the seeds (at least at 1.50 when I tried it last). As for the formula to use, it should be the first one you used, rounded down when the result isn't a whole number. If the wiki says 19 days instead of 18, they probably made a mistake, although like you I haven't measured it specifically for sweet gem berries myself

[BeastWalnut]

Ursprünglich geschrieben von carl8000:

I'm sure he's figured it out over the past few months, but the scenario TC wants isn't possible since you can't add fertilizer days after you plant the seeds (at least at 1.50 when I tried it last). As for the formula to use, it should be the first one you used, rounded down when the result isn't a whole number. If the wiki says 19 days instead of 18, they probably made a mistake, although like you I haven't measured it specifically for sweet gem berries myself

Wiki says fertilizers cant be used after planting but speed-gro can be as it is not the same

[ShiZniTe]

not very well.

[carl8000]

Ursprünglich geschrieben von BeastWalnut:

Ursprünglich geschrieben von carl8000:

I'm sure he's figured it out over the past few months, but the scenario TC wants isn't possible since you can't add fertilizer days after you plant the seeds (at least at 1.50 when I tried it last). As for the formula to use, it should be the first one you used, rounded down when the result isn't a whole number. If the wiki says 19 days instead of 18, they probably made a mistake, although like you I haven't measured it specifically for sweet gem berries myself

Wiki says fertilizers cant be used after planting but speed-gro can be as it is not the same

Yeah, looks like I was lying, my bad. I just did a quick trial using 5 cauliflower where I used deluxe speed gro for one on the planting day, and then added it 2 days later for another, 4 days later for another, and 6 & 8. I was able to add it as per the wiki, and I can confirm that it reduced the *remaining* grow time by 25% (rounded in your favour)--the 1st cauliflower was ripe after 9 days, 2nd & 3rd were ripe after 10 days, 4th & 5th after 11 days. Sorry for speaking out of turn earlier