How long for seeds to sprout when germinated directly into soil?

1-2 weeks if you just popped them in soil no prep. This is what I did my very first grow, it took 9-10 days to pop. If you helped them along by soaking in anything before hand or altering the seed by means of scarification, it should speed it up a bit. could be looking at 3-5 days maybe 8. If nothing is happening after a full week they might have drowned. I find when I don't wait and go digging I damage them. keep temps 22-26c day time and higher humidity. Drop that back at night. My method that works well goes like this. 1. scarify the seed with a emery board in the palm of your hand just rolling it around gently not pushing to hard. Then nick the fat bottom with one mini swipe on the emery board. 2. soak in warm tap water, 12hr max, you don't need to PH balance it but can if you want. also optional any mycorrhizae/bacteria incontinent in the water with it. 3. make a hole 1/2"-1 1/2" deep with pencil or finger, lace hole with dry mycorrhizae, drop in seed and lightly cover. If its tap root is extended be gentle. 4. lightly water with a mix of liquid mycorrhizae and beneficial bacteria, helps molds stay away. 5. keep temps up in day 22-26c cool at night 18-20c and RH at least 60% at most 80% and a small fan. 5b. I also prewet my medium before I plant to get the right consistency, then the 2nd watering step 4, is just to wash over the small area where you just dropped the seed. best of luck