You may start picking leaves in 4 weeks after planting.
Basil likes to be cut! You can start trimming your plants in about one month after planting. You may remove single leaves occasionally. But, for more thriving growth pinching off the whole tip is recommended - it will grow two new shoots in a week.
Cutting and pruning your plant will also delay its flowering.
When basil starts to flower, the taste changes - for some people it will be too bitter. It is up to you - if you want to see how a basil’s flower and what it’s seeds look like, don’t cut your plant anymore. If you like to keep using the leaves, cut the plant strongly back.
But notice, that basil is an annual plant. It does not last forever. If your 70 days old basil looks old already, well, it is time to replace the pod.