Dead and dying trees on Tolworth greenway will not be replaced until September.
The cypress trees, described as "hardy" on gardening websites, have become brown and threadbare since the greenway opened last November.
Geoff Poyzer, from contractor North Midland Construction, said: "Our landscape contractor will replace any dead trees during the planting season in September."
A Kingston Council spokesman said: “Six Italian cypress trees have now been found to be dead or dying and will be replaced at the contractor’s expense.
"Six other trees are showing signs of stress. Should these trees die, they too will be replaced at no expense to the council.
"We are looking into the reasons behind these trees not successfully establishing themselves.
"Approximately 60 new trees were planted as part of the Tolworth Greenway scheme.
"According to government guidelines it is not uncommon for up to 23 per cent of newly planted street trees to die.
"The contractor visits the site regularly to maintain all of the new trees and shrubs planted and will do so up to November 2016."
What sort of tree would you like to see on the greenway? Write to email@example.com.