The money will be used to fund a five-year programme managing the disease, also known as sudden oak death, alongside P. kernoviae.
This decision follows the consultation launched by Defra, the Forestry Commission and the Welsh Assembly Government last July.
The consultation paper asked the industry at what level the diseases P. ramorum and P. kernoviae should be managed.
The announcement took place at National Trust property Nymans Garden in West Sussex. Head gardener Ed Ikin showed the minister and other visitors plants that are susceptible to the disease, such as Rhododendron and Viburnum.
Representatives from the HTA, RHS and National Trust were present at the meeting.
For reaction see Friday 6 March issue of Horticulture Week magazine.