"While many of the heats are held at colleges, we want young people below age 30 in all sectors to enter," said a competition spokesman.
Prizes valued at more than £10,000 are up for grabs, including a £2,000 Percy Thrower travel bursary. Regional heats will take place in Great Britain and Ireland from early next year with the final set for 5 May.
Last year, Royal Parks apprentices and young employees from garden centres entered for the first time. Bursary winner Suzanne Moss said she planned to travel to Madagascar to study native flora. For more details, email email@example.com.