Hampton Court Palace Garden Festival was scheduled for 7 – 12 July.
RHS Tatton Park Flower Show was scheduled 22 – 26 July.
RHS Wisley Flower Show will be cancelled this year was scheduled 8-13 September and will be replaced by Hampton Court, which is a ticket-based event, while Wisley is not.
RHS Hyde Hall Flower Show has been postponed to 2-6 September from 5 – 9 August and RHS Rosemoor Flower Show has been postponed to 18-20 September from 14 – 16 August.
Earlier in the season RHS shows including Chelsea, Chatsworth and Cardiff have already been cancelled.
Sue Biggs, RHS director general, said: “The RHS is extremely sad to miss this important event and seeing so many friends at Tatton and we are currently considering a virtual show as a way to stay in touch with exhibitors and the community that love Tatton as much as we do.
“We are also sorry to cancel our very special Wisley Flower Show, but with moving Hampton dates it does not make sense to hold two Flower Shows, in such close in proximity, so close in time. We hope that the joy of returning to Wisley in summer will be reason enough for our much valued members and visitors to come and see us again.”
"We will contact everyone who has purchased a ticket to the affected shows to offer later show dates, refunds and other options should they wish to show their support of the RHS.
“We continue to carefully follow Government advice and make responsible decisions with the health and safety of people always at the front of our minds.
“As well as being much loved by visitors, RHS Hampton Court Palace Garden Festival is a really important platform for the horticultural industry. We are sorry to not be able to hold our wonderful Tatton Show, however, we look forward to returning to the North West in a big way in 2021 with the return of Tatton Park and the opening of RHS Garden Bridgewater.
"All future planned RHS shows are of course subject to Government advice allowing them to take place."