Bugs

Inch by Inch by Leo Lionni
Space Spinners by Suse MacDonald
Insects Are My Life by Megan McDonald
A House of Leaves by Kiyoshi Soya
The Lady and the Spider by Faith McNulty
The Spider Who Created the World by Amy MacDonald
Three Brave Women by C.L.G. Martin
When the Woods Hum by Joanne Ryder
Mr. Carey's Garden by Jane Cutler

Butterflies

The Great Monarch Butterfly Chase by R.W.N. Prior
The Caterpillars' Wedding by Shen Roddie
Gotta Go! Gotta Go! By Sam
The Butterfly Hunt by Yoshi
The Butterfly Kiss by Marcial Bóo
Monarch Magic: Butterfly Activities & Nature Discoveries by Lynn M. Rosenblatt (good resource book)

Colors in the Garden

The Rainbow Goblins by Ul de Rico
The Blue Thing by Daniel Manus Pinkwater
Rainbow-Flower by Valentin Katayev
Planting a Rainbow by Lois Ehlert
The Great Blueness by Arnold Lobel
Red Day, Green Day by Edith Kunhardt
The Gift of Driscoll Lipscomb by Sarah Yamaka
Little Blue and Little Yellow by Leo Lionni
A Color of His Own by Leo Lionni

Dandelions

Dandelion Adventures by L. Patricia Kite
Barney Bipple's Magic Dandelions by Carol Chapman
Dandelion by Ladislav Svatos
The Life Cycle of the Dandelion by Paula Z. Hogan
Amy Loves the Sun by Julia Hoban
Dandelions Are Growing by Ruth Dale

Gardens

This Is Your Garden by Maggie Smith
Daisy's Garden by Mordicai Gerstein
Bumblebee, Bumblebee, Do You Know Me? by Anne Rockwell
Too Many Hopkins by Tomie DePaola
Can I Help? by Marilyn Janovitz
The Garden of Happiness by Erika Tamar
Grandpa's Too-Good Garden by James Stevenson
Flower Garden by Eve Bunting
Home Lovely by Lynne Rae Perkins
My Day in the Garden by Miela Ford
Rosa's Special Garden by Dale H. Fife
Eve and Smithy by Michelle Edwards
Vegetable Garden by Douglas Florian

Harvest

The Enormous Turnip by Kathy Parkinson
Oliver's Vegetables by Vivian French
The Giant Vegetable Garden by Nadine Bernard Westcott
Silly Tails by Jan Mark
Green Beans by Elizabeth Thomas
A Pumpkin Story by Mariko Shinju
The Ugly Vegetables by Grace Lin

Other Animals that Live in the Garden

Miss Emma's Wild Garden by Anna Grossnickle Hines
Even That Moose Won't Listen to Me by Martha G. Alexander
Murgatroyd's Garden by Judy Zavos
Nuts to You! by Lois Ehlert
Mushroom in the Rain by Mirra Ginsburg
A House of Leaves by Kiyoshi Soya

Rain and Clouds

Little Cloud by Eric Carle
The Rain Cloud by Mary Rayner
Will It Rain? by Holly Keller
James and the Rain by Karla Kuskin
The Cloud Book by Tomie de Paola
Rain Drop Splash by Alvin Tresselt

Rocks

Anansi and the Moss-Covered Rock by Eric A. Kimmel
I Am A Rock by Jean Marzollo
Milk Rock by Jeff Kaufman
Sylvester and the Magic Pebble by William Steig
Elizabeti's Doll by Stephanie Stuve Bodeen
A Rumbly Tumbly Glittery Gritty Place by Mary Lyn Ray
Everybody Needs a Rock by Byrd Baylor
The Big Rock by Bruce Hiscock
Meteor by Patricia Polacco

Roses

Wanda's Roses by Pat Brisson
Nora's Roses by Satomi Ichikawa

Seeds

What's so Terrible about Swallowing an Apple Seed? by Harriet Lerner and Susan Goldhor
Titch by Pat Hutchins
"The Garden" (from Frog and Toad Together) by Arnold Lobel
The Tiny Seed by Eric Carle
The Surprise Garden by Zoe Hall
The Carrot Seed by Ruth Krauss
The Squirrel and the Moon by Eleanor Schmid
The Reason for a Flower by Ruth Heller
I'm a Seed by Jean Marzollo
Look at Seeds and Weeds by Rena K. Kirkpatrick

Trees

Have You Seen Trees? by Joanne Oppenheim
The Magic Leaf by Winifred Morris
The Gumdrop Tree by Elizabeth Spurr
Cherry Tree by Ruskin Bond
The Peach Tree by Norman Pike
Mighty Tree by Dick Gackenbach
One Blowy Night by Nick Butterworth
A Leaf Named Bud by Paula Schwartz and Sara Schwartz
The Big Tree by Bruce Hiscock
Mary Margaret's Tree by Blair Drawson
The Squirrel and the Moon by Eleanor Schmid
Eucalyptus Wings by J. Alison James
Pearl Plants a Tree by Jane Breskin Zalben
The Tree Suitcase by David Suzuki

Walking in the Garden

The Listening Walk by Paul Showers
Nature Walk by Douglas Florian
Goblin Walk by Tony Johnston
I Went Walking by Sue Williams
A Walk to the Great Mystery by Virginia A. Stroud
Sarah's Questions by Harriet Ziefert
Dancing the Breeze by George Shannon

Wildflowers

Miss Emma's Wild Garden by Anna Grossnickle Hines
Miss Rumphius by Barbara Cooney
Wildflowers and the Stories Behind their Names by Phyllis S. Busch
A Child's Book of Wildflowers by M.A. Kelly
Look at Seeds and Weeds by Rena K. Kirkpatrick