| Common Name | Red Maple |
| Botanical Name | Acer rumbrum L. |
| Mature Size | 40 to 70 feet tall (occasionally taller) with a spread of 30 to 50 feet |
| Sun Exposure | Full to partial sun |
| Soil Type | Adaptable; sandy to clay |
| Soil pH | 4.5 to 6.5 |
| Bloom Time | Spring |
| Flower Color | Red |
| Care | From March to May, small red flowers appear. The reddish "helicopter" fruit/seed pods appear in early spring before leaves flesh out. The leaves are two to five inches long, with the classic 3- to 5-lobed structure common to maples. As they first unfurl in spring the leaves have reddish highlights, changing to green as they open. Unlike silver maples, the spaces between lobes on red maples are relatively shallow in depth. The leaves are dark green on the top, with grayish bottom surfaces. Leaf margins are toothed, with pointed tips. Most varieties turn a bright crimson red in fall, but some cultivars exhibit orange or yellow autumn foliage. |
| Soil | The tree prefers acidic to neutral soils, and won't do well in alkaline conditions. Red maples grown in alkaline soil will yield pale leaves and stunted growth. While red maple can live in a range of soils, it cannot tolerate salt. |
| Water | Red maples prefer somewhat moist soil but will grow fine in dry soils provided you are willing to irrigate them regularly (slow, deep watering is the ideal). Once established, make sure the soil remains moist—a layer of organic mulch around the base of the tree will help. Make sure the tree gets a deep watering each week, either by irrigation or by rainfall; do not let the soil dry out. |
| Temperature and Humidity | Red maple can survive in both dry and moist areas ranging from dry ridges to bogs. It can grow on mountainous areas, swampy areas, and along streams. While it does require some cooler weather, it is found as far north as Newfoundland and as far south as the Carolinas. |
| Fertilizer | Fertilization is usually not necessary, but when needed, a general-purpose fertilizer applied in spring is sufficient. Use a three-inch layer of mulch to help soil hold moisture. |
| Pruning | Pruning is rarely necessary, but you should remove branches to avoid very narrow angles between trunk and branches as wide angles will be stronger. The red maple is very sensitive to pruning, so generally you should avoid cutting branches larger than a few inches in diameter. Cuts should be made just outside the branch collar to help the tree close the wounds. When you do prune, do it at the end of summer or in autumn; the tree tends to bleed sap when pruned early in the growing season. |
| Source | https://www.thespruce.com/growing-the-red-maple-acer-rubrum-3269321 |