Speaker Art van Wingerden of Metrolina Greenhouses, North Carolina, told the audience of bedding plant growers that automation was preferable to "stagnation".
He said he turns crops five times a year at his 168 acres nursery, which also has 257 acres outdoor space.
He said technology has progressed from transplanters in the 1980s to next generation 100 per cent fill transplanters being trialled now.
Using cranes increases nursery space use from 71 to 87 per cent, while Metrolina's 12 x $30,000 robots space 250 pots per robot per hour.
Sticking machines are the newest innovation, from ISO Group and Visser in Holland. These can stick 2 million cuttings a week.
Also being trialled, are drones to spray crops evenly and electrostatic spraying.
Dr Matthew Howard of Kings College London spoke on GROWBOT, a grower-programmable robot he is working on. He said 'soft' robots that can handle fruit are being developed.
What robots do for nurseries was Professor Simon Pearson of University of Lincoln's talk. He said tethered Danish trolleys pulled in a train, mobile automated trolleys, collaborative robots and picking systems were on the horizon. Autonomous vehicles for carrying platforms on nurseries and using UV light applied by robots to control powdery mildew are further innovations. Palletisation by £20,000 robots is a mass market opportunity, he added.
He said using robots was rising up people's agendas now leaving the EU was nearing, which could mean labour supply for Europe is harder to source..