For gardeners and other plant-lovers, here's a sampling of regional events:

" 20th Annual Benefit Plant Sale Camellia, mangolia & rhododendron sale. University of Delaware Botanic Gardens, 531 S. College Ave., Newark. 4/27.

" 47th Annual Plant Sale Hanging baskets, herbs, flowers, grasses & more. Benefits area beautification projects. Genesis HealthCare Corp., 101 E. State St., Kennett Square. 4/28. 8 am-4 pm.

" 7th Annual Earth Day Pinelands Native Plant Sale Cultivated trees, shrubs, and native Pinelands flowers for purchase. See the Pinelands photo exhibit, hear a lecture, enter a raffle, and visit some local vendors. Bishop Farmstead, 17 Pemberton Rd, Vincentown. 4/28. 11 am-3 pm.

" A Birding Adventure Guided bird walk. Bring binoculars if you have them. Norristown Farm Park, 2500 Upper Farm Rd., Norristown. Registration required: 610-270-0215. 4/28. 8 am.

" American Rhododendron Society Plant Sale & Flower Show Rhododendrons, azaleas, hydrangeas & other plants. Mercer County Community College, 1200 Old Trenton Rd., Princeton; 215-589-9931. 4/28. 9 am-1 pm.

" Annual Wissahickon Creek Clean Up Help clean the Wissahickon Creek and enjoy a picnic afterward. Wissahickon Valley Park, 300 E. Northwestern Ave. Registration required: WVWA: 215-646-8866 x14. 4/28. 9 am-12 pm.

Arboretum Tour Focuses on some of the park's native & exotic tree species. Bellevue State Park, 800 Carr Rd., Wilmington. Registration required: 302-761-6963. $5. 4/28. 1-3 pm.

Backyard Habitat Plant Swap Swap a plant or two for new ones brought by other attendees. Nature Center of Cape May, 1600 Delaware Ave., Cape May; 609-898-8848. One plant and a new or used garden tool. 4/28. 10 am.

Bird Walk Volunteers from the Museum of Natural History lead bird walks through the park. Wear comfortable hiking shoes. Brandywine Creek State Park, 41 Adams Dam Rd., Greenville. Included in admission. 4/28.

Bird Walks Sat. Call 215-345-7860 for more information. Peace Valley Nature Center, 170 Chapman Rd., Doylestown. Donation suggested: $2. 4/28.

Birding With Ruth Bird walk led by experienced area birdwatcher Ruth Pfeffer. Norristown Farm Park, 2500 Upper Farm Rd., Norristown; 610-270-0215. www.birdingwithruth.com. 4/29.

Briar Bush Tour Garden tour led by a naturalist from Briar Bush Nature Center. Chanticleer Garden, 786 Church Rd., Wayne; 215-887-6603. $45. 5/2. 9:15-2:30 pm.

Cape May Garden Tours Scenic walk through a variety of Cape May gardens. Downtown Cape May, Downtown Cape May, Cape May; 609- 884-5508, ext. 102. $10. 4/28.

" EarthFest One of the largest Earth Day celebrations on the East Coast. Temple University Ambler, 580 Meetinghouse Rd., Ambler. 4/27. 9:30-3 pm.

" Eco Friendly Gardening Program on the benefits of environmentally friendly fertilizers & weed/pest management. Floral & Hardy, 4007 Skippack Pike, Skippack. 5/2. 6:30 pm.

" Guided Tour Spring tour of the arboretum's grounds. Swarthmore College — Scott Arboretum, 500 College Ave., Swarthmore; 610-328-8025. 4/28. 10-11:30 am.

Herb Container Gardening Class on creating a mini herb garden in various types of containers. Jenkins Arboretum, 631 Berwyn Baptist Rd., Devon; Registration required. $35. 4/28. 10 am-12 pm.

How to Propagate Begonias Fairmount Park Horticultural Center, N. Horticultural Dr. Registration required: wiener1@verizon.net. 4/28. 10 am.

Master Gardeners of Chester County Garden Fair & Sale Workshops & classes on various gardening topics, demonstrations, plant sale & silent auction. East Goshen Township Building, 1580 Paoli Pike, West Chester; nds13@psu.edu. www.facebook.com/ChesterCountyMasterGardeners. $25 advance; $35 day of event. 4/28. 9 am-3 pm.

Mount Laurel Garden Club Plant Sale Mount Laurel Library, 100 Walt Whitman Ave., Mount Laurel. Registration required: 856-234-7319. mtlaurelgardenclub.com. Purchase of plants. 4/28. 9 am-12 pm.

" Naturepalooza Nature-themed programming in honor of Earth Day. Music by The Plants, animal shows, crafts, nature walks. The Schuylkill Center, 8480 Hagy's Mill Rd. 4/28. 10 am-2 pm.

Seedlings Nature-themed play activities for young kids. The Schuylkill Center, 8480 Hagy's Mill Rd.; 215-482-7300 x 110. $8. 4/30.

" Spring Bird WalkTake a walk through the preserve with experienced, local birding guides with a chance to see a variety of species, including warblers, thrushes, towhees, goldfinches, chickadees, woodpeckers. Departs from the Visitors Center; binoculars recommended. Bowman's Hill Wildflower Preserve, 1635 River Rd., New Hope; RSVP at 215-862-2924. www.bhwp.org. 4/28.

Spring Garden Gala: Wild About Flowers Dinner & auctions to benefit the Preserve. Bowman's Hill Wildflower Preserve, 1635 River Rd., New Hope; RSVP at 215-862-2924. $175-$250. 4/28. 5-10 pm.

" Spring Native Plant Sale The Schuylkill Center, 8480 Hagy's Mill Rd. 4/28.

Spring Wildflower Tour Mount Cuba Center, 3120 Barley Mill Rd., Hockessin, Del. Registration required: 302-239-4244. $5. 4/27.

" Spring Wildflower Walk Search the park for wildflowers in bloom. Wissahickon Valley Park, 300 E. Northwestern Ave. Reservations recommended. 4/28. 10 am-12 pm.

" Susan Conner: My Garden Collection Recent oils of gardens, parks & preserves. Delaware Center for Horticulture, 1810 N. Dupont St., Wilmington; 302-658-6262. 4/27.

" Tree Peony Collection Tour & Reception The Mid-Atlantic Peony Society presents a Peony Collection tour followed by a reception. Swarthmore College — Scott Arboretum, 500 College Ave., Swarthmore; 610-328-8025. 5/2. 5-7 pm.

Tyler Gardens & Landscaping Lecture Presentation on gardening with less water, followed by a tour of the Tyler Gardens. Bucks County Community College, 275 Swamp Rd., Newtown. $15; $7 students with ID. 4/28. 9:30 am.

Vertical Gardening Using Pallets Learn how to use a wooden pallet to create a "green wall." Greensgrow Farms, 2501 E. Cumberland St. $20. 4/28. 12-2 pm.

Water Explorers Visit local wetlands Cobbs Creek Community Environmental Education Center, 63rd & Catharine Sts. $9. 4/28. 11 am-12 pm.

Wee Have Fun Club Nature, story & art activities for young kids. Bellevue State Park, 800 Carr Rd., Wilmington. $4. 5/3.

" Wildflower Celebration Live music, learning stations, raptor demonstrations & family activities. Mount Cuba Center, 3120 Barley Mill Rd., Hockessin, Del. 4/29. 10 am-4 pm.

Wildflower WalkA month of guided tours offered Tuesday through Sunday at 2 p.m. See flowers and fruits in seaso, discover fun facts about their use and learn about the preserve's history. Tours leave from the Visitor Center for a minimum of two visitors, weather permitting. Bowman's Hill Wildflower Preserve, 1635 River Rd., New Hope; RSVP at 215-862-2924. Included with admission. 4/27.

Send information about gardening and horticultural events to gardenscoop@phillynews.com. Include a contact number and send at least two weeks before the event.