And set on a quiet windowsill with sunlight. Itâ€™s helpful to make use of a clear glass so you may easily see when roots start to develop, and also when the water needs to be modified. Many guides advocate to alter the water on daily basis, but I discovered, by trial and error, that it is better to alter the water every 5 days to every week or so. You do need to ensure you modify the water often, to prevent mold, micro organism and fungus growth, which may doom your little avocado sprout. Many online guides I’ve read say that sprouting can take anyplace from 2-4 weeks, but in my experience, it usually takes at least 8 weeks to get a sprout, so be patient. 1. The top of the avocado pit will dry out and kind a crack, and the outer brown seed skin will slough off. 2. The crack will extend all the approach to the underside of the avocado pit, and through the crack at the bottom, a tiny taproot will begin to emerge.