The £500,000 pilot project will test the effect of natural techniques on slowing down the flow of water off the hills and reduce the risk of flooding downstream.
It is part of the Leeds Flood Alleviation Scheme, a partnership between Leeds Council and the Environment Agency, who intend to more than double canopy coverage in the Aire catchment.
Leeds Council leader, Councillor Judith Blake, planted the first of 450 trees at Ray Bridge Farm, Eshton Beck, Gargrave, yesterday.
At this first pilot site, tree species such as dogwood, guelder rose, downy birch, alder and willow will be planted alongside hedgerows.
The pilot site will allow evidence to be gathered on how trees reduce flood risk and will inform projects proposed elsewhere.
Coun Blake, said: “These new trees are a hugely significant part of our plans to protect Leeds from future flooding like the devastation we saw on Boxing Day 2015.
“They are part of what will be a range of natural flood management measures in a catchment wide approach to prevent future catastrophic floods affecting communities along the river.”
Hundreds more trees are set to be planted in the Yorkshire Dales.
To reduce its carbon footprint, Cooper King Distillery in Sutton-on-the-Forest near York, has pledged to plant one square metre of native woodland for every bottle of gin it sells.
In partnership with Yorkshire Dales Millennium Trust, up to 5,000 sq m of woodland will be planted over the next 12 months.