Guides · Tree database · Medium tree
Weeping willow: mature size, roots and how far from the house to plant it
Weeping willow, Salix babylonica: how big it gets, what its roots do, and the planting distances to keep from a house, patio, septic field, sewer line and power lines, with a checker for your spot.
Weeping willow grows 30–40 ft tall and 30–40 ft wide, per NC State Extension. Plant it at least 20 ft from the house, 15 ft from a patio or driveway, 40 ft from a septic field and 20 ft from a sewer line. It grows too tall for under power lines. Checked Nov. 13, 2026.
Is your spot far enough away?
| House | — |
| Patio, driveway or walk | — |
| Septic field | — |
| Sewer line | — |
| Power lines | — |
Measure from the trunk. The rules behind each number are in the table below. Your township, utility or septic permit can set its own setbacks.
Weeping willow facts
| Mature height | 30–40 ft |
|---|---|
| Mature width | 30–40 ft |
| Size class | Medium |
| Growth rate | Rapid |
| Hardiness zones | 6a–8b |
| Light | Full sun (6 or more hours of direct sunlight a day) |
| Soil | Frequent Standing Water |
| Form | Broad |
| Origin | East Asia–China |
| Fall color | Gold/Yellow |
From NC State Extension. Its zone range includes zone 6, which covers most of central Pennsylvania; check your own with our hardiness zone by ZIP tool.
Weeping willow roots
Invasive roots can damage water or sewage pipes (NC State). Willows are on Iowa State’s list and not recommended near leach fields (Virginia Tech).
Iowa State Extension lists it among trees with abundant surface roots, and the University of Florida says to keep trees with aggressive roots 10 to 15 ft from pavement.
How far to plant weeping willow from things
| From | Plant at least | The rule |
|---|---|---|
| House or building | 20 ft | Half the mature canopy width (eXtension) |
| Patio, driveway or walk | 15 ft | Aggressive roots: 10 to 15 ft (University of Florida) |
| Septic drain field | 40 ft | At least the root spread, estimated from mature height (Virginia Cooperative Extension), or the canopy width (University of Florida), and no closer than 20 ft for small trees (UMaine) |
| Sewer line or lateral | 20 ft | “Do not plant trees within 20 feet” of a sewer line (PA Water Environment Association) |
| Overhead power lines | 50 ft | Tall-growing trees at least 50 ft from lines (PPL Electric) |
| Retaining wall | 20 ft | At least 5 ft from the wall, with the canopy edge behind the wall (CMHA) |
Distances use the top of the size range, measured from the trunk. The full sources are in our tree planting distance guide.
Other medium trees
40–50 ft tall, 35–50 ft wide. Plant 25 ft from the house.
30–40 ft tall, 20–30 ft wide. Plant 15 ft from the house.
20–30 ft tall, 15–30 ft wide. Plant 15 ft from the house.
20–30 ft tall, 25–35 ft wide. Plant 18 ft from the house.
25–30 ft tall, 15–20 ft wide. Plant 10 ft from the house.
20–30 ft tall, 20–35 ft wide. Plant 18 ft from the house.
How to identify weeping willow
| Leaf type | Alternate, simple leaves with toothed edges |
|---|---|
| Leaves | Very narrow leaves 3 to 6 inches long and only 3/8 to 1/2 inch wide, finely toothed, yellow-green on top. |
| Bark | Grayish brown with irregular furrows. |
| Fruit | Small clusters of capsules with cottony seeds, ripe in late May to early June. |
| Twigs | Very slender olive-green to yellowish twigs that hang straight down. |
PNHP lists the weeping willows growing wild in Pennsylvania as hybrids (Salix ×sepulcralis and ×pendulina); the description here follows Virginia Tech’s weeping willow fact sheet.
The Pennsylvania Natural Heritage Program (PNHP) lists weeping willow as introduced: it is not native to Pennsylvania.
Look-alikes: White willow, Black willow.
Identification notes from the Virginia Tech Dendrology fact sheet, in our own words; status from the PNHP PA Vascular Plant List. See all 140 trees in our Pennsylvania tree identification guide.
Questions
How big does weeping willow get?
Weeping willow grows 30–40 ft tall and 30–40 ft wide at maturity, per NC State Extension. Growth rate: rapid.
How far from the house should you plant weeping willow?
At least 20 ft, half of its 30–40 ft mature width, so the canopy clears the house. Keep it 15 ft from a patio or driveway.
Do weeping willow roots damage foundations, patios or pipes?
Invasive roots can damage water or sewage pipes (NC State). Willows are on Iowa State’s list and not recommended near leach fields (Virginia Tech).
What zones does weeping willow grow in?
Weeping willow is listed for USDA zones 6a–8b by NC State Extension. That includes zone 6, which covers most of central Pennsylvania.
Can weeping willow go under power lines?
No. At 30–40 ft it outgrows the 25 ft limit for trees under lines; PPL says to plant tall-growing trees at least 50 ft from lines.
Sources: NC State Extension (Salix babylonica); planting distances from the sources in our tree planting distance guide: eXtension, Morton Arboretum, Iowa State, University of Florida, Virginia Cooperative Extension, UMaine, PA Water Environment Association, PPL Electric, WV Forestry and CMHA. Checked Nov. 13, 2026.
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