Spyder7answered grow question 5 years ago There's nothing provided as a reference point to gauge their size, but I wouldn't put too much into any size expectations around day 22, without some reason to (like discovering a ph problem).
My last grow was an Early Miss 7 week auto (60% indica/30 sativa/10% ruderalls) and it only began to enter the pre-flower stretch on day 22. Up until day 22, it looked like a small shrub (though it is a dwarf strain); but in the two weeks after day 22, during the pre-flower stretch, it got so big I had to defoliate it as it was outgrowing my tent and was too thick for the light to penetrate.
Even after defoliating my first grow (breaking the rule about not doing it your first grow), made mistakes with light, watering, humidity, and was giving it very little nutes, it still yielded about an ounce in a tiny tent, with a 2 gallon pot and 150W LED.
So I wouldn't stress over it. If you get the nutes, ph, and light dialed in, you'll see a lot of growth in the next two weeks as you go through the stretch.