The phrase here, as in many places in Exodus through Deuteronomy where God gives commands, is בְּנֵי יִשְׂרָאֵל. Literally this is "sons of Israel", though some translations say "children of Israel" instead.
In Hebrew all nouns have gender (there is no neuter), so a masculine plural like בְּנֵי means either an all-male group or a mixed group. (You only see the feminine plural if all members of the group are feminine.) So grammatically speaking this is ambiguous, and we have to look at other uses.
Unfortunately, there isn't a clear pattern just from the text; for example, in Ex 20 masculine language is used for both general command (like "do not murder") and one that seems to apply just to men ("do not covet your neighbor's wife"; no I'm not considering modern sexuality here). When the language is ambiguous, as in the passage in this question, the rabbis looked for both other contextual clues (e.g. is this a man's garment that's being discussed?) and received tradition. A question about the specific case of tzitzit might be better asked on Mi Yodeya.
There are some cases where the text clearly addresses both men and women. One place where the text is more explicit is in Lev 19:
דַּבֵּר אֶל-כָּל-עֲדַת בְּנֵי-יִשְׂרָאֵל
Speak unto all the congregation of the children of Israel
After which we get the holiness code. Because it says "all the congregation" it is clear that it includes men and women. Similarly, Deut 2:4 says to command הָעָם, the people, and that includes everybody (it's related to their travels). So more-general terms are used in the text, but not most of the time.
Please note: This answer was written for a neutral, academic audience
and is not intended to be interpreted in the context of a religious
belief or doctrine.