I love how you have tied it all to a nature theme. Wonderful. I am also of the thought that less is more. It has only taken me years to figure that out!!
Picture study, simply display the print/calendar page on a cookbook stand (I set it out Sunday nite so it’s like a surprise Monday morning) of our artist of choice for the term. Last year also tried to cram in too much so I was changing it every week doing 2 artists a term. This year, for most terms, there will be 6 pictures set out for 2 wks. And I try to find a picture book about the artist and read it one day.
Music study, play a cd or online selection of our single composer per term, for a while when we do crafts, baking, art, playdough, legos in the afternoons after they’ve been playing outside for awhile. Try to find a picture book on composer or audio cd like Classical Composers for Kids one time. In the summers, I have all the cd’s out so they can pick and listen as they like to.
Poetry, well I love to read it out loud, and so will often pick one to read at lunchtime or before quiet time in the afternoon with snack, only takes a couple minutes.
Art – on bad weather days we all work on a handicraft/hobby of choice or one together (they often join me in my hobbies/crafts like papermaking, soapmaking, card making, gardening as they have interest/ability). They have a couple baskets of craft supplies, recyclables that they do their own crafts with whenever they like. Once a week, I try and have them pick something to draw in nature notebook (or tape in, rubbing, take a picture and print and tape in etc.), and pick one art medium to work with: painting, drawing, playdough/clay, chalk, etc. once a week after lunch one day (or whenever the mood strikes us).