The Hopkinton Garden Club’s Speaker Series presents a double session on Tuesday, Feb. 21, on Zoom. From 7-7:30 p.m., Ed Harrow will discuss the battle against knotweed and other invasives in Hopkinton. From 7:30-8:30, Robert Gegear will present “A citizen scientist’s guide to native pollination system conservation (and why it matters).” This event, supported in part by a grant from the Hopkinton Cultural Council, is free and open to the public. For more information, visit hopkintongardenclub.org or email register@hopkintongardenclub.org.