SATURDAY Cockrell Butterfly Center Fall Plant Sale: 9 a.m.-noon, or until sold out, outside the main entrance of the Houston Museum of Natural Science, 5555 Hermann Park Drive; 713-639-4753, hmns.org. Free. Beginner Bird-watching: with Kelsey Low. 9:30-11:30 a.m. at the Houston Arboretum and Nature Center, 4501 Woodway; 713-681-8433, register at houstonarboretum.org. $20 member, $35 nonmembers; ages 13 and older. Scarecrow Making Time: 10 a.m. at Enchanted Forest, 10611 FM 2759, Richmond, reservations 281-937-9449; 2 p.m. at Enchanted Gardens, 6420 FM 359, Richmond, reservations 281-341-1206; myenchanted.com. $20. Hanging Baskets: with Jim Maas & Pat Cordray. 10 a.m. at Maas Nursery, 5511 Todville, Seabrook; 281-474-2488, maasnursery.

SATURDAY Bulb Mania: with Houston Garden Club member Dodie Jackson. 9-11 a.m. at Texas A&M AgriLife Extension Service, 4102-B Main, La Marque; 281-534-3413, email registration to galvcountymgs@gmail.com, aggie-horticulture.tamu.edu/galveston. Free, but registration required. Basic Organic Vegetable Gardening: sponsored by Urban Harvest. 9:30-11:30 a.m. at the University of St. Thomas, 3812 Yoakum; 713-880-5540, urbanharvest.org. $30. Gardening for Hummingbirds & Birds Class: with Jim Maas, Pat Cordray and Jean Griffin. 10 a.m. at Maas Nursery, 5511 Todville, Seabrook; 281-474-2488, maasnursery.com. $40. Peckerwood Garden Open Day: 10 a.m.-3 p.m. at Peckerwood Garden, 20559 FM 359, Hempstead; 979-826-3232; register at peckerwoodgarden.

Fifty or so inches of rain in just a few days is enough to turn any lawn into a soggy mess. And if poor drainage has left puddles where there ought to be tufts of grass, you might just have a new outdoor project on your hands. Never mind that grass isn't meant to live under water for days on end. It's also not meant to be a filter for all kinds of toxins - hydrocarbon contamination or even sewage - that floated in with floodwaters. Zach Buchanan, operations manager at Buchanan's Native Plants, said Hurricane Harvey's heavy rains and floodwaters will stress virtually every lawn and landscape. How they react to that stress will vary. So keep an eye on your yard, document when changes happen and how quickly they spread.

As the floodwaters of Hurricane Harvey subside, you don't have rush to fix things in your yard or garden. An initial cleanup should involve removing debris and fallen branches; you don't want detrimental fungi from rotting debris to spread to healthy plants. After that, plants just need a good rinse, said Angela Chandler, author of the Garden Academy blog and consultant to Urban Harvest. "It sounds counter-intuitive but, really, things just need to be washed off. As quickly as you can, rinse your garden off with plain water," she said. Any mud or dirt left behind on plants will reduce photosynthesis; they need sunlight for their own natural recovery. The most basic problem right now is the amount of oxygen in our soil.

SATURDAY Fall Vegetable Gardening: with Jim Maas, Pat Cordray and Lisa Gaige. 10 a.m. at Maas Nursery, 5511 Todville, Seabrook; 281-474-2488, maasnursery.com. $40. Peckerwood Garden Open Day: 10 a.m.-3 p.m. at Peckerwood Garden, 20559 FM 359, Hempstead; 979-826-3232; register at peckerwoodgarden.org. $10. SEPT. 2 Insider's Tour: The North Dry Garden: 10 a.m.-noon at Peckerwood Garden, 20559 FM 359, Hempstead; 979-826-3232; register at peckerwoodgarden.org. $15. SEPT. 7 Small Ornamental Trees for the Houston Area: with Linda Gay; Nottingham Country Garden Club program. 9:30 a.m. at the Municipal Utility Building, 805 Hidden Canyon, Katy; ncgctx.org. Free. SEPT.

SATURDAY Plumeria: with Jim Maas and Loretta Osteen. 10 a.m. at Maas Nursery, 5511 Todville, Seabrook; 281-474-2488, maasnursery.com. $25. Fall Vegetables: Harris County Master Gardener Green Thumb program. 10 a.m. at Maud Smith Marks Library, 1815 Westgreen, Katy; 713-274-0950, hcmga.tamu.edu. Free. MONDAY Harris County Master Gardeners Precinct 2 Open Garden Day: 8:30-11 a.m. at Genoa Friendship Garden, 1202 Genoa Red Bluff; Master Gardeners will answer gardening questions. hcmga.tamu.edu. Free. TUESDAY Harris County Master Gardeners' Open Garden Day and Fall Vegetables Seminar: 9-11:30 a.m. at Texas A&M AgriLife Extension Service, 3033 Bear Creek; hands-on activities for children and adults centered on seminar topic. RSVP to ogd.

Houston gardeners shared these photos of plants blooming in their summer beds.

Montgomery County Master Gardeners' program. 9-11 a.m. at Texas A&M AgriLife Extension Service, 9020 Airport, Conroe; 936-539-7824, mcmga.com. $5. Rain Gardens: with Charriss York from the Texas Coastal Watershed Program. A Homeowner's Guide to Weed Control: with Galveston County Master Gardener John Jons. 6:30-8 p.m. at AgriLife Extension Service, 4102 Main, La Marque; 281-534-3413, email reservations to galvcountymgs@gmail.com, aggiehorticulture.tamu.edu/galveston Free, but pre-registration required. Gardening Tips for Growing Native Plants: with Thomas Adams, Texas Midcoast Refuge botanist. Harris County Master Gardeners Precinct 2 Open Garden Day: 8:30-11 a.m. at the Genoa Friendship Garden, 1202 Genoa Red Bluff; hcmga.tamu.edu. Harris County Master Gardeners' Open Garden Day and Fall Vegetables seminar: 9-11:30 a.m. at Texas A&M AgriLife Extension Service, 3033 Bear Creek; hands-on activities for children and adults centered on seminar topic.

Peckerwood Insider's Tour: monthly focused look at the garden. 10 a.m. at Peckerwood Garden, 20559 FM 359, Hempstead; 979-826-3232; register at peckerwoodgarden.org. $15, members free. Harris County Master Gardeners Precinct 2 Open Garden Day: 8:30-11 a.m. at Genoa Friendship Garden, 1202 Genoa Red Bluff; Master Gardeners will answer gardening questions. hcmga.tamu.edu. Attracting Bluebirds to Your Garden: with Master Gardener and Master Naturalist Linda Crum. 10-11:30 a.m. at Genoa Friendship Garden, 1202 Genoa Red Bluff; Master Gardeners will answer gardening questions. hcmga.tamu.edu. Rainwater Harvesting and Water Conservation: with extension horticulturist Skip Richter. 7:30 p.m. at the Cherie Flores Garden Pavilion in McGovern Centennial Gardens, 1500 Hermann Drive; houstonrose.org. Montgomery County Master Gardeners' program. 9-11 a.m. at Texas A&M AgriLife Extension Service, 9020 Airport, Conroe; 936-539-7824, mcmga.com. $5. Rain Gardens: with Charriss York from the Texas Coastal Watershed Program. A Homeowner's Guide to Weed Control: with Galveston County Master Gardener John Jons. 6:30-8 p.m. at AgriLife Extension Service, 4102 Main, La Marque; 281-534-3413, email reservations to galvcountymgs@gmail.com, aggiehorticulture.tamu.edu/galveston Free, but pre-registration required. Evening at Peckerwood Garden Lecture: with horticulturist Adam Black. 5-7 p.m. at Peckerwood Garden, 20559 FM 359, Hempstead; 979-826-3232; register at peckerwoodgarden.org. $10 nonmembers, members $5.

Houston-area gardeners shared these photos of plants that beat the heat. 

SATURDAY-SUNDAY Christmas in July: 9 a.m.-5 p.m. Saturday, 10 a.m.-5 p.m. Sunday at Another Place in Time, 1102 Tulane; 713-864-9717. Free. TUESDAY Gardening by the Square Foot: with Galveston County Master Gardener John Jons. 6:30-8 p.m. at Texas A&M AgriLife Extension Service, 4102 Main, La Marque; 281-534-3413, email reservations to galvcountymgs@gmail.com, aggiehorticulture.tamu.edu/galveston Free, but pre-registration required. WEDNESDAY Mercer Botanic Gardens Student Research Symposium: 5:30-8 p.m. at Mercer Botanic Gardens, 22306 Aldine Westfield, Humble; register at 713-274-4160. Free but donations appreciated. FRIDAY Project Learning Tree: 9:30 a.m.-4 p.m.