Warm hours see the greatest activity. Popular butterfly habitats include:
Backyard-
Herb Garden: Monarchs around the Asclepias tuberosa - aka Butterfly Weed description orange and red flowers on 1-3' tall perennial
Backwall, North Corner: Variety of visitors on Buddleja davidii, aka Butterfly Bush description - Tall shrub dull green foliage and spike of deep purple fragrant flowers just starting
Forecourt & Herb Garden: Mourning Cloaks on Echium candicans aka Pride of Madeira - description - Grey green felted foliage (can irritate skin so don't pet it!). Attention grabbing flower spike of 1-2" feet of blue spike. so busy with bees, butterflies and hummingbirds an air traffic controller could be employed.
Soil Cement Drive at top of stairs from Ca, Native Garden: Cloudless Sulphur on Senna didymobotrya aka Cassia - Shrub in pots and one in the ground at margin of drive. Medium green aromatic foliage with tall spikes of brilliant yellow flowers. Look for caterpillars too! they can be yellow, green or striped with both colors
Visitor Center big island planter: a variety of visitors on Verbena lilacina 'De La Miona' aka Cedros Island Verbena - description soft mound of delicate green foliage topped with fragrant purple flowers spilling over the curb adjacent the California Native Garden enroute to Inner Courtyard
Swallowtails have started showing up but I have not pinpointed a target plant
When you park your car in the lower lot, know that critters observed there are considered part of the project scope!