Possible Clues:

• Plant work consumes early spring day?
• Large bush with stiff leaves and pink or white flowers
• River is close to oak tree
• Job around first day of spring perhaps to find tree
• Tree Commission met around St David's Day
• A job to hold Welsh festival in small tree
• Scotsman takes a chance on a shrub
• The tree is hazardous for me after tea
• Shrub with pink flowers
• To turn it over on the floor gets to be hazardous for a tree