Sugar maple

About Sugar maple

Sugar maple is the big native maple of the Northeast and Midwest, the tree tapped for maple syrup and famous for yellow, orange and red fall color. It grows slowly into a dense, spreading crown that casts deep shade. It dislikes heat, drought, compacted soil, road salt and pollution, so it does best in roomy lawns and parks rather than along streets.

Zones 3-8 (NC State). In warmer areas choose heat-tolerant cultivars such as 'Bonfire' or 'Morton'.

When to plant

Timing is counted from your average last spring frost (and first fall frost). Sow & Tell works out the actual dates for your ZIP code.

Plant container or balled-and-burlapped trees. Container trees can go in any time the ground can be worked, but fall is the best season in the South because roots keep growing through mild weather (Clemson). Dig the hole no deeper than the root ball and at least twice as wide, keep the top roots level with the soil, and mulch 2-4 inches without touching the trunk. Roots can crack sidewalks and clog drains and septic lines, so give it space (NC State).

Soil

Fertile, moist, well-drained soil that is slightly acidic; it does poorly in compacted, salty or very dry soil (NC State).

Test the soil first. Loosen a wide planting area and mix 10-20 percent compost into the native soil you dig out; don't use uncomposted bark, and don't dig deeper than the root ball (Clemson).

Feeding

• Spring to early summer, after the tree is established, and only if a soil test or pale leaves and weak twig growth show a need: slow-release nitrogen fertilizer with a ratio near 3-1-1 or 3-1-2 (3-0-1 or 3-0-2 if the soil test shows enough phosphorus). Spread it evenly from just outside the trunk flare to the dripline and water it in. Clemson cites 2-4 lb of slow-release nitrogen per 1,000 sq ft per year, split into a spring and a late-summer feeding; follow your soil test.
• Late summer to early fall, the second half of the year's split feeding (only if a soil test calls for it): slow-release nitrogen fertilizer, same as spring. Clemson advises giving red and sugar maples only part of the year's amount late in the season; water in, and skip it if the tree is drought-stressed.

First-year watering matters far more than fertilizer: water daily for the first 1-2 weeks, every 2-3 days until week 12, then weekly, using about 1-1.5 gallons per inch of trunk diameter, until the tree is established, roughly 1.5 years per inch of trunk (UMN). Don't count on rain unless it was over an inch. Avoid compacting the root zone, piling soil over roots, and road salt; sugar maple tolerates none of them well (NC State). Too much fertilizer can burn roots and push soft growth that pests and cold injure (Clemson).

Varieties (7)

NC State documents 7 cultivars, several picked for heat tolerance.

Pests to watch for

Aphids, Scale insects, Annual cicadas (dog-day cicadas), Boxelder bugs, Asian longhorned beetle, Winter moth, Cankerworms (fall and spring cankerworms)

Diseases and problems

Verticillium wilt, Anthracnose, Tar spot, Leaf scorch, Canker, Leaf spot, Overwatering and waterlogged soil, Drought stress, Winter injury, Mechanical damage (mower, trimmer and tie wounds), Road salt injury, Girdling roots, Bacterial leaf scorch

In the kitchen

The sap is boiled down into maple syrup. Trees are usually around 40 years old before tapping, and it takes about 32 gallons of sap to make 1 gallon of syrup (NC State).

Pets: Not on the ASPCA's toxic plant list for dogs. The ASPCA's maple warning for horses is for red maple.