"When do you take care of the horses?"
Translation:Kdy se staráte o koně?
Checked with a Czech and she said if you use 'Kdy se o koně staráš ty' you would typically come with more information, either before or after. like 'Kdy se o koně staráš ty, žerou?' - 'when you take care of the horses, do they eat?' And you could also say 'Oni žerou, kdy se o koně staráš ty?' COOL!
First, please read the question by Laszlo.Sz and the answers.
Please understand that if you change the word order, you are changing the meaning. You cannot just shuffle the words randomly, even if the resulting sentence is grammatically correct. See https://en.wikipedia.org/wiki/Topic_and_comment
Your proposed sentence very likely says something different that you may think it says. It strongly stresses the verb and makes it the main point of the sentence. "When do you take CARE of the horses?" It is quite strange here, really. Take care as opposed to what?
I think in the present tense it is more like wondering that it is strange that you are not doing it presently. The when are you gonna do it already would be "Starat se o koně budete kdy?" but most often that is used to say you sheould be doing it now insteasd of what you are doing or what you are going to do.