Most disappointed outdoor growers ordered on time for the wrong date. The arithmetic that fixes it takes one minute.
Count backwards from planting day. Rooting and dispatch take up to two weeks, transit takes a few days, and hardening off takes about a week. That is roughly three weeks from click to soil. For most northern states with a late-May planting date, that puts the order in the middle of April.
Ordering earlier than that is fine if you have indoor space to hold the plants; ordering later is how people end up hardening off in a hurry and planting stressed seedlings into cold ground.
Cuts are taken and rooted to order rather than pulled off a shelf. That window is the rooting itself: a fresh cutting needs time under humidity to build the root mass that lets it survive shipping and transplanting. A nursery that promises a next-day dispatch on live cuttings is either sitting on aging stock or shipping something under-rooted.
Treat the window as quality assurance rather than a delay. The plant that leaves after a proper rooting period is the plant that arrives worth planting.
Indoor growers order year-round and think this question is strange. Outdoor growers should not: a January delivery means holding plants under lights for months, which turns a clone into a leggy, root-bound problem before the season starts. The exception is a mother-plant strategy, where holding in veg is the entire plan.
Extreme cold is also a transit risk. If your winter lows run hard, the sensible move is waiting for spring or arranging a carrier hold instead of a doorstep drop.
Hold the plants in veg under lights or in a bright window; a clone can wait weeks with no harm if it is potted up as it grows. What it cannot do is sit in its shipping container indefinitely, which is how root binding starts. Check your state's page on this site for the local frost math, then order against that date instead of the calendar's idea of spring. The marijuana clones shipped manifest sorts by flowering window, so you can also solve a late start by choosing a faster finisher.
Written by Mike Hawley for the Marijuana Clones Shipped reference desk.