Mercer Botanic Gardens: Free Gardens and Trails Near Houston

At a glance

• Where: 22306 Aldine Westfield Rd, Humble, TX 77338
• Hours: Typically 8 a.m.–5 p.m. (winter), to 7–8 p.m. in spring and fall; closed Thanksgiving, Christmas, and New Year's Day. Check the official site before you go.
• Cost: Free admission; free parking
• Parking: Free lot at the main entrance on Aldine Westfield Rd; separate lot on the arboretum (west) side
• Time needed: 1.5–3 hours for the gardens; add an hour for the arboretum trail

Mercer Botanic Gardens in Humble, TX is a free 393-acre public garden about 25 miles north of downtown Houston. Admission is free, parking is free, and the garden is open daily except three holidays. Most people outside the immediate area don't know it exists — which is part of what makes it worth the drive. Mercer draws around 200,000 to 250,000 visitors a year almost entirely by word of mouth.

The gardens sit at 22306 Aldine Westfield Road and split into two distinct halves divided by the road. The east side holds the cultivated botanic collections — more than 60 themed areas, including the largest ginger collection in Southeast Texas. The west side is the natural woodland arboretum, where Cypress Creek runs through a riparian forest of bald cypress and hickory. Both sides are worth your time.

The two sides of Mercer

The cultivated gardens (east side) hold the botanical collections across 60 cultivated acres: a ginger garden, a bamboo grove, a prehistoric garden of cycads, a children's garden, a shade garden with a wooden boardwalk, a pollinator garden with a honeybee corral, a native plant area, a pocket prairie, an herb garden, and the William D. Lee Louisiana Iris Collection at Storey Lake. That iris collection — irises in red, copper, lemon yellow, and deep blue — is one of the most striking things you can see here in spring.

No dogs are allowed in the cultivated gardens (service animals excepted). Paths are paved or compacted gravel with very little elevation change, and most areas are accessible.

The arboretum (west side) is entirely different: a natural riparian forest where Cypress Creek forms the northern boundary. Bald cypresses, hickory bogs, and bottomland hardwoods line the water. This side welcomes leashed dogs on a 6-foot lead, has 58 picnic tables, two pavilions, and two playgrounds, and connects to the trail network along the creek.

What blooms when at Mercer

Mercer has something in flower in every season, which is why repeat visitors keep coming back.

Winter (January–March): Camellias are the main event. The collection holds 41 plants representing 36 cultivars, some planted by Thelma Mercer herself in the 1940s and 1950s, and it is an official stop on the American Camellia Trail. This is a quieter time to visit, with smaller crowds and easy parking.

Spring (February–April): The azalea trail and berms put on a major show in late February through April. Dogwoods, magnolias, and Louisiana irises follow. The William D. Lee Iris Collection at Storey Lake peaks in March and April with red and copper varieties that photograph well against the water. This is also when the March Mart plant sale happens.

Summer (June–October): The ginger garden and tropical collections peak. Heliconias, torch gingers, Costus, and related species bloom in oranges, reds, pinks, and white throughout the heat. Most visitors skip summer, which means the gardens are largely yours.

Fall (September–November): Salvias, Turk's cap, and pentas attract hummingbirds during the September migration. The ginger garden is still in bloom. October and November are among the most comfortable months to visit.

Cypress Creek trails and the arboretum

The trail network at Mercer covers about 5.7 miles across both sides of the road. The main loop on the arboretum side runs about 2.6 miles through the riparian forest — flat, shaded, and well-marked, rated easy for all fitness levels. Cypress Creek sections are good birding territory during migration season; warblers, hawks, and bald eagles have all been reported here.

The trail surface is mostly natural and can be muddy after rain. Wear shoes you don't mind getting dirty. Cypress Creek is also a kayaking and paddling route near Houston if you want to extend the day on the water.

The March Mart plant sale

Twice a year, the Friends of Mercer Botanic Gardens (also called The Mercer Society) runs a plant sale that Houston-area plant collectors put on their annual calendar.

The spring sale — March Mart — is typically held over two days in the third week of March and includes around 1,600 plant varieties, many rare or unavailable at retail nurseries: specialty gingers, unusual ferns, tropical shrubs, Louisiana irises, heritage roses, and native trees. There is a members-only preview evening before the public sale opens.

The fall sale typically runs in September. For current dates and VIP preview night details, check friendsofmercer.com before making plans. There is no online purchasing; attendance is in person only.

Best photo spots at Mercer

• Storey Lake and the irises (March–April): Walk the path around the oxbow lake when the Louisiana irises bloom. The red and copper varieties against the water are hard to beat.
• The shade garden boardwalk: Good in any season. Morning light in early spring is ideal for the fern collections.
• The ginger garden (July–September): Torch gingers reach eight feet tall. Go early for the best light and fewest people.
• The bamboo grove: Tall vertical forms photograph cleanly, with a small clearing inside the collection.
• Thelma's Pond (koi pond): A central landmark with bench seating. Camellias frame it in winter.
• The Cypress Creek overlook (arboretum side): Best in fall when the bald cypresses turn golden before dropping their needles.

Tips and best time to visit

The best overall months are March, April, October, and November. Spring delivers the biggest floral show; fall has comfortable temperatures and the hummingbird migration.

Hours change by season. In winter, closing time is typically 5 p.m. From spring through fall, the park stays open until 7 or 8 p.m. Check the Harris County Precinct 3 parks page before you go, especially in the shoulder months.

Bring water and a snack. There are fountains and restrooms on site but no cafe or food vendor inside the gardens.

The Harvey story. Hurricane Harvey in 2017 submerged the entire property under 10 to 12 feet of floodwater. The visitor center closed and did not reopen until January 2023 — a six-year restoration. The plants, including camellias Thelma Mercer planted in the 1950s, survived. If you are visiting for the first time, know that the gardens are healthy and actively expanding; the restoration story is part of what makes this place worth knowing.

Is Mercer Botanic Gardens free?

Yes. Admission and parking are both free. Mercer Botanic Gardens is operated by Harris County Precinct 3 as a public park with no entry fees on either the cultivated gardens or the arboretum side. Donations to the Friends of Mercer support the plant collections.

Getting there and parking

The main entrance is at 22306 Aldine Westfield Road, Humble, TX 77338. Free parking is in the lot directly off Aldine Westfield Road. The arboretum has a separate free parking area on the west side of the road.

From downtown Houston, take I-45 North to FM 1960 East, then head north on Aldine Westfield Road. The drive takes about 35–40 minutes without traffic. There is no METRO bus service to this location; a car is the practical way to get here.

For more on the surrounding area, see the Humble neighborhood guide and things to do in Humble.

Food nearby

There is no food inside the gardens. For a meal after your visit, the best restaurants in Humble guide covers options along FM 1960 and the surrounding streets. For a fuller day out, Kingwood is 10–15 minutes east and has additional dining options.

Nearby things to do

For a longer day, our day trips from Houston guide and hiking trails near Houston guide cover more options in this part of Harris County. For a full picture of Houston-area green spaces, the Houston parks guide and Houston Arboretum guide round out the picture.

Last verified: October 2026.

Frequently asked questions

Is Mercer Botanic Gardens free?

Yes. Admission and parking are both free. Mercer Botanic Gardens is operated by Harris County Precinct 3 as a public park with no entry fees for either the cultivated gardens or the arboretum.

Can I bring my dog to Mercer Botanic Gardens?

Dogs on a 6-foot leash are welcome on the arboretum (west) side of the road. They are not permitted in the cultivated botanic gardens on the east side, except for ADA service animals.

Where is Mercer Botanic Gardens located?

Mercer Botanic Gardens is at 22306 Aldine Westfield Road, Humble, TX 77338, about 25 miles north of downtown Houston. From I-45 North, take FM 1960 East and then head north on Aldine Westfield Road.

When is the Mercer Botanic Gardens plant sale?

The Friends of Mercer run two plant sales per year: March Mart in late March (typically two days, in-person only, with around 1,600 varieties) and a fall sale in September. Current dates are posted at friendsofmercer.com.

What is blooming at Mercer Botanic Gardens in spring?

In spring (February through April), azaleas, dogwoods, magnolias, and Louisiana irises are the highlights. The William D. Lee Louisiana Iris Collection at Storey Lake peaks in March and April with red, copper, yellow, and blue varieties.

How long are the trails at Mercer Botanic Gardens?

The trail network totals about 5.7 miles across both sides of the road. The main loop on the arboretum side is about 2.6 miles, rated easy, flat, and mostly shaded.