The aggregated totals, top mortality causes and common maintenance methods are summarised below. A proportion of councils did not plant trees or did not monitor tree planting or death rates. Councils that responded after the deadline (18 August) have not been included.
Overall tree-planting and survival totals
Note: Total counts combine recorded standard trees and whips across responding councils. Loss rates vary significantly by type. Standard specimen trees averaged 8-15% mortality, whereas whip/woodland plantings in drought-affected regions experienced losses between 20% and 70%.
Street trees face severe mortality risks without human intervention. RHS chief horticultural adviser Guy Barter says gardeners can help by watering young trees using household greywater and ensuring that they have weed-free base zones for their first two years.
“My council put in trees and they put these water bags round them,” adds Barter. “They had quite a good take. There’s a few dead trees about, but yes, if people have a tree in the street outside and they want to water it, I’m sure the councils would be only too pleased — ideally using grey water, of course, from the kitchen or something like that.
“But yes, that would be a really good thing. And keep the tree weeded as well, of course, so the weeds don’t rob the poor old tree of moisture.
“It’s been something that’s been in the public mind for at least 50 years, hasn’t it? I remember they said ‘plant a tree in 73 and watch it die in 75’. The Forestry Commission did lots of research after that particular episode and discovered that trees need to be watered and kept weed-free for the first two years of their life. After that, they could look out for themselves.
“That sort of knowledge and understanding, I think, sometimes gets lost. So it’s well to remind ourselves that smaller trees take better than bigger ones, and all trees need to be kept weed-free and watered — or usually watered — for the first two years of their lives, and then you’ll have something that can carry on for the next 60 years or more.”
Without proper aftercare and establishment, many newly planted trees will fail before they ever reach maturity, the Arboricultural Association maintains.
Research suggests that around 30% of newly planted street trees die within their first years, often due to lack of watering and aftercare during dry weather. Young trees are particularly vulnerable during periods of heat and drought — and with climate change bringing more frequent extremes, supporting tree establishment has never been more important.
The association is encouraging residents, community groups and local authorities to work together to help young trees thrive by watering trees near them throughout the summer.
Since launching in 2020, the campaign has distributed more than 20,000 tree-watering tags, including thousands of free packs for community groups, schools and volunteers across the UK. The tags act as a simple reminder for residents to help care for newly planted trees in their neighbourhoods.
Detailed findings by category
1. Standard and heavy standard trees
Overall survival rate:
Generally high, averaging 80-95% across most councils.
Mortality characteristics:
Because standard trees receive dedicated aftercare (such as weekly/fortnightly watering and hydration bags), they withstand drought periods much better than whips.
Leading causes of death:
i. Vandalism and physical damage. Being planted in high-footfall urban areas, standard trees suffered significantly from snapped trunks, bark stripping and vehicle impact (e.g. Walsall reported 96% of standard failures were due to vandalism, while Wandsworth and Haringey noted vandalism as top causes).
ii. Severe water stress. When drought was extreme, even watered standard trees suffered root shock or failure if watering could not keep pace with high temperatures.
Examples from data:
- London Borough of Barnet: 925 standards planted, 21 lost (2.3%)
- Newcastle City Council: 2,084 standards planted, 217 lost (10.4%)
- Essex County Council: 643 standards planted, 15 lost (2.3%)
2. Whips and saplings
Overall survival rate:
Highly volatile, averaging 30-80% depending heavily on summer rainfall and local weather conditions.
Mortality characteristics:
Whips were planted in large volumes without dedicated watering regimes (relying on natural rainfall and mulch). The unusually dry spring and summer of 2025 caused catastrophic losses in certain regions.
Leading causes of death:
i. Drought and lack of Irrigation. Without deep-root networks, young saplings dried out quickly during prolonged hot spells.
ii. Overgrowth and competition: Grasses, brambles and weeds outcompeted whips for groundwater and choked young stems.
iii. Animal predation: Deer, rabbits and voles stripped bark or foliage where guards failed.
Examples from data:
- Sunderland: 2,000 whips planted, 950 lost (47.5%)
- Warwick District: 3,050 whips planted, 1,050 lost (34.4%)
- Essex County Council: 63,695 whips planted, 15,250 lost (23.9%)
- Rochford District: 3,281 whips planted, 2,264 lost (69% — due to severe weather)
Key takeaway
Standard trees represent a high-cost, low-mortality investment protected by intensive local aftercare, whereas whips are a low-cost, high-volume strategy where councils intentionally over-plant (accepting 20%-plus baseline losses) to allow natural selection to form dense canopy cover.
However, increasingly frequent summer droughts are pushing whip mortality past manageable thresholds.
Top reasons for tree death
1. Drought, extreme heat and lack of water — 86 mentions
By far the single largest cause of failure. The prolonged dry spells in spring and summer caused severe water stress, rapid dehydration and transplant shock, particularly in areas without active irrigation or retentive soil.
2. Vandalism, theft and antisocial behaviour — 64 mentions
Physical damage included snapped trunks, trees pulled out of the ground, stolen stock and damaged protective cages/stakes (especially prevalent in urban parks, verges and housing estates).
3. Animal browsing and wildlife damage — 16 mentions
Damage caused by deer, rabbits, hares, voles and livestock eating bark or leaves, often occurring where guards/shelters failed or were absent.
4. Poor stock quality and transplant shock — 16 mentions
Trees failing to leaf or establish post-planting due to root handling pre-planting, poor nursery stock or poor initial planting technique (e.g. root collar planted below ground level).
5. Competition from weeds and overgrowth — 12 mentions
Unmanaged grass, brambles and weeds around the base competing directly for soil moisture and nutrients.
6. Accidental and mechanical damage — 9 mentions
Collisions from vehicles along highway verges, strimmer/mower strikes at the base during lawn maintenance and dog-urine damage.
7. Poor soil conditions — 8 mentions
Compacted, thin or nutrient-deficient “made ground” along roadside verges, as well as salt-laden coastal winds causing desiccation.
Most common maintenance methods
Regular watering regimes:
Frequency: Fortnightly to weekly visits between April and September (typically eight to 22 rounds per growing season).
Volume: 20-70 litres of water per standard tree per visit.
Equipment: Hydration/gator slow-release drip bags (50-75L capacity), mobile water bowsers and installed underground irrigation pipes.
Mulching:
Applying a 60-75mm layer of woodchip/bark mulch or mulch mats in a 1m-diameter circle around the base to retain moisture and suppress competing weeds.
Stake, tie and guard adjustments:
Routine checking and adjusting of tree ties to prevent stem strangulation, resecuring loose stakes and maintaining weldmesh cages or rabbit/deer shelters.
Weed control and vegetation clearance:
Hand-pulling weeds, spot-spraying herbicide or strimming around the base to clear a 0.5-1m weed-free zone.
Monitoring and beating up:
Conducting summer/autumn survival checks (“beat-up” surveys) to identify dead or dying stock for replacement in the subsequent winter planting season.
Public sector tender specifications
Half of public sector tenders do not specify tree maintenance alongside planting.
The antidote to high tree losses is for tree establishment to be funded within tenders for tree planting, something for which tree specialists such as Tony Kirkham and Jeremy Barrell have long campaigned.
HortWeek has gathered years’ worth of data on public sector tenders as part of its Tenders Tracker subscriber service. We analysed available tree-planting tenders issued on public sector tender platforms during the 2024-25 season, to see whether tree establishment was included in specifications.
Findings:
For tree-planting tenders pertaining to the 2024-25 season, nine out of 17 tenders did not mention establishment or maintenance.
Among those that did specify tree maintenance, the majority allowed three-to-five years for establishment.
Although tender descriptions and specifications vary in detail, among the nine public sector clients that did not specify tree establishment, all but one were short-term contracts that would not have allowed time for any establishment or maintenance work to take place.
Client types included local authorities across the UK and one national park authority.
