In Houston, it’s time to select and plant trees
National Arbor Day is celebrated in April each year, but that’s the ideal planting time for northern regions of the U.S. Texas Arbor Day is situated in the fall, when digits are lower, drought is reduced and roots on newly planted trees flourish.
To establish new trees, you want to plant in late fall or winter and ensure you are planting the right tree for the space.
Whether you are looking for a small tree to accent the back patio with fragrant flowers or a large behemoth to help cut air conditioning costs, there is a tree right for your situation.
Large trees
Drummond red maple, Acer rubrum var. Drummondii, grows between 30 and 50 feet in height. Small, red, spring flowers are not as showy as the red fall foliage that can vary depending on environmental conditions.
Shumard oak, Quercus shumardii, grows up to 80 feet in height or more. The deciduous, glossy foliage is red in the fall. Male flowers on catkins are 5-7 inches long in the spring. It is tolerant of acidic and mildly alkaline soils.
Other trees to consider: white oak, red oak, Mexican sycamore, chinquapin oak, eastern cottonwood, American beech, tulip poplar
Small to medium trees
Mexican buckeye, Ungnadia speciosa, has pink blooms that are close to the trunk, resembling the redbud. It develops an interesting three-valved seedpod. Its autumn color is bright yellow. If not grown as a multitrunked shrub, it can be pruned to one trunk as a small tree, growing between 15-30 feet tall.
Chalk maple, Acer leucoderme, can be difficult to find. It only grows 12-15 feet tall. As an understory tree, it prefers part shade, tends to be multitrunked unless pruned to one trunk and prefers well-drained soil. Yellow flowers bloom in the spring, while fall foliage varies between yellow and deep red.
Other trees to consider: yaupon holly, magnolia sweetbay, Texas olive (Cordia boissieri), fringe tree, Mexican plum, eastern redbud, Texas paloverde, possumhaw holly
Making great selections
Fort Bend County extension horticulture agent Boone Holladay encourages diversity in tree canopy to provide more resilience against new stressors that manifest throughout the year, including cold, heat, drought, disease and pests. “Good plant selections may not last forever, as discovered with the recent pest impacts from crape myrtle bark scale and emerald ash borer,” Holladay said.
Holladay shared tips for selecting the right tree for the right place:
• Select healthy trees from nurseries. Look for good structure, no signs of stress or disease and examine for a healthy root system. Avoid overgrown roots.
• Younger trees in 3- to 5gallon pots are recommended. They have not been in the containers long and tend to be more vigorous than older, larger containerized stock. As a result, they establish quicker in the ground.
• Research species selection. Understand the mature parameters of the tree. These include height, canopy diameter, root zone and whether it is deciduous or evergreen.
• Ensure plant site does not limit tree growth. Check for utility easements, power lines, drainage and proximity to home, driveways and sidewalks.
Tree-planting tips
Remove from pot and assess the roots. If it is a young tree, tease the roots out with your fingers to encourage outward growth. If the roots are dense, cut down the sides in three or four spots and tease out.
To avoid digging and moving dirt unnecessarily, plant tree in a hole that matches the pot. Afterward, insert a shovel 6 to 8 inches outside the edge of the hole and push the soil toward the root ball. Do this all around to loosen soil and fill around the new planting.
Use the same soil from the hole. Amending with compost, potting soil, or peat moss keeps the roots from extending out.
Create a bed of at least 8 feet in diameter to avoid cutting roots when expanding a bed. Some trees start out with a taproot, but even they mature to a shallower root system that can grow two and a half times the branch spread.
Plant the tree no deeper than it was planted in the pot, with the root flare visible above soil and mulch. If the root flare was buried in the pot, then unearth it. Planting a tree too deeply encourages pests and disease on otherwise healthy bark.
Create a soil or mulch berm for more efficient watering in heavy soils around the diameter of the planting. Fill inside the berm with water and allow the soil to slowly absorb it, reducing runoff.
During the fall months, water twice a week for the first few weeks with average weather, but account for rain. Reduce watering to once a week, then water only when needed. By the time the heat arrives, your tree should have a great start.
Texas A&M Forest Service Texas Tree Planting Guide can offer suggestions: texastreeplanting.tamu.edu.