Hare Hatch only has planning permission for a plant nursery.
A Wokingham Borough Council representative said: "The time period for compliance is 18 months.
"This time period is longer than usual as Wokingham Borough Council has taken into account the difficulties of ceasing use, removing structures, potential difficulty for business, potential loss of employment and time to allow for discussions with the local planning authority for how the site might be developed to meet a negotiated solution."
The enforcement notice was issued on October 25, for planning breaches that included use of land as a garden centre, a cafe, shops, an events area, a children’s play area, siting of a mobile home and parking.
Hare Hatch Sheeplands' Rob Scott said: "The enforcement notice requires us to cease (within 18 months) a number of activities on the site that Wokingham Borough Council consider are unlawful in planning terms. These include the children’s play site and our events arena, which is so popular as a venue with many local village organisations.
"Just to recap on the situation. For the past four and a half years we have been in close discussion with planners at Wokingham as we developed our plans for the site. It would have been possible for us to seek planning approval for each separate improvement as we went along. Moving the toilets under cover is one example. Instead, as requested by the Council, we submitted a "master plan" showing how we intended to develop the site into a sound and viable business for the long-term future.
"The planning application for the "master plan" was refused by Wokingham Borough Council in December last year.
"A planning Inquiry was scheduled for November 27, when an independent Inspector would have considered our proposals and taken a decision on which parts of the plan would be allowed or refused. The Inquiry has, however, been adjourned so that the enforcement notices can be dealt with at the same time. Should the enforcement notice be upheld, it would have an extremely serious and detrimental impact on our business.
"We met with Planning Officers at Wokingham Borough Council on Tuesday (November 20) to begin a dialogue that will hopefully result in a compromise being reached. The current position is, however, very serious and we are extremely concerned about the future viability of the business. We will continue to do everything we can to resolve the situation and are grateful for the unwavering support of our staff and customers."