Star-shaped leaves that blaze yellow, orange and red in autumn, and spiky ball-shaped fruits that appear only once the tree has passed twenty-five years. Sweetgum (Liquidambar styraciflua) is a North American tree grown both for ornament and for furniture-grade timber. Give it full sun and soil that drains freely, and that autumn display is yours.
| Name | Liquidambar styraciflua |
|---|---|
| Family | Hamamelidaceae |
| Type | tree |
| Height | 25 to 115 feet (8 to 35 m) |
| Soil | ordinary, well drained |
| Exposure | full sun |
| Foliage | deciduous |
It is recommended to plant sweetgum in fall to allow for root development before winter.
You may also plant container-bought sweetgum in spring.
Note that the size of sweetgum trees is very variable, and ranges from 25 to 115 feet (8 to 35 m) depending on the variety and the growing conditions.
Sweetgum requires no pruning, unless you’re compelled to do it.
During the first two years after planting, water your sweetgum regularly, especially in case of dry spell or extreme heat.
Once properly settled in, sweetgum normally is able to answer its needs by finding water in the soil on its own, so no need to water anymore.
Sweetgum asks for very little once settled, but each task has its own moment in the year. Here is what to do, and when.
| Task | When | What to do |
|---|---|---|
| Planting | Fall, or spring for container-grown plants | Plant in an isolated, spacious spot in full sun so roots settle before winter |
| Mulching | After planting, kept topped up | Shields the tree from late spring frosts and keeps the soil cool through summer |
| Pruning | Spring, only if needed | Remove dead, weak or damaged branches; otherwise leave the natural shape alone |
| Watering | First two years after planting | Water regularly, above all in dry spells or extreme heat; afterwards the tree copes alone |
| Feeding | Regularly, as amendments | Manure and seaweed support growth; fertiliser will not make the tree grow faster |
Beyond these few interventions, an established sweetgum is essentially self-sufficient.
Named forms differ mainly in autumn colour, in the shape they make and in whether they drop those spiky balls. The table below sets out the sweetgums most often found in garden centres and mainstream catalogues.
| Variety | Autumn colour | Habit | Notable feature |
|---|---|---|---|
| Lane Roberts | Deep blackish crimson | Tall, rounded-conical | RHS Award of Garden Merit; very reliable colour |
| Worplesdon | Orange, yellow then purple | Tall, broadly conical | RHS Award of Garden Merit; narrow, deeply cut lobes |
| Rotundiloba | Purple-red, late | Tall, upright | Fruitless; rounded leaf lobes |
| Silver King | Rose-pink to purple | Medium, slow | Cream-white leaf margins |
| Golden Treasure | Gold with crimson | Medium, slow, compact | Yellow-margined leaves all summer |
| Gum Ball | Red to purple | Dwarf, rounded | Usually sold top-grafted as a standard |
| Burgundy | Deep wine-red | Tall, upright | Holds its leaves late; suits mild areas |
| Festival | Yellow, peach and pink | Tall, narrowly upright | Multi-toned display; mild climates |
| Parasol | Deep red | Medium, broad rounded crown | Dome-shaped head for shade |
| Slender Silhouette | Yellow to burgundy | Very narrow, columnar | For tight spaces and avenues |
| Palo Alto | Orange to fiery red | Tall, upright oval | Copes with hot, dry summers |
| Moraine | Bright red | Tall, oval | Chosen for cold-winter gardens |
| Happidaze | Red to burgundy | Tall, symmetrical oval | Essentially fruitless; street and lawn tree |
Native to North America, sweetgum is a very ornamental tree that also procures excellent quality wood for furniture-making. It is also more familiar to many under the name liquidambar. It’s sometimes even written out “Liquid Amber tree”, which is also true in a way!
From its wood and fruits, a sap can be extracted, usually called sweetgum balsam or Peru balsam that the Cherokee Indians used as chewing gum and is today used in infusions for its capacity to sooth the respiratory system, fight diarrhea and reduce stress.
Sweetgum is also a true marvel in fall with its purple hues that set the garden on fire.
Note that if your sweetgum doesn’t bear fruit, this is probably because it is a sterile cultivar called Liquidambar styraciflua ‘Rotundiloba’ that was created specifically so that the fruits, which are very slippery when burst, would not lead to accidents on parkings or along roads.
Sweetgum never bears fruit before the age of 25 years.
Growth is relatively slow.
Adding fertilizer won’t speed it up, however, regular amendments based on manure and seaweed will actively support the proper growth of the tree.
