For spring planting, mix the seeds with moist sand and refrigerate for 30 days before direct sowing. Benefits Motivating, inspiring, mood booster. Unlike other milkweeds, butterfly weed does not have caustic milky sap, but it does produce the characteristic seed pods that release silky-tailed seeds to disperse on the wind.  Source: <a href=https://www.trade-forums.co.uk/thread/12071>https://www.trade-forums.co.uk/thread/12071</a>