When to harvest ?

While there will always be few variations, you can use the following rules to better identify the harvest window of your plants according to the ripening stage of their trichomes: 1) When the bulbous heads of the trichomes are fully developed but still translucent, plants will produce a "high" and stimulanting effect, less sedative. It is the perfect moment to harvest strong Indica strains. 2) When these bulbous heads turn milky is probably the best moment to harvest most available hybrids. 3) When 70% of these trichome heads are milky and 30% amber, it is the perfect time to harvest mostly Sativa hybrids and long flowering strains (like Haze). It is also the best moment to harvest plants for making hashish.

And btw, seed banks are in the business of selling seeds... so their "estimates" of when you'll be able to harvest are just that - estimates - and usually count on perfect conditions grown by expert growers who have been very lucky. It's pretty usual to find their estimates are off by 2, 3, or 4 weeks! Go by the trichs, not the sales pitch!