Kinglea has appointed administrative receivers Geoff Kinland and William Turner BDO after "difficult trading conditions" led to a multi-million pound debt.
Based in Nazeing, Essex, Kinglea has 200 full-time and seasonal employees. The nursery supplies bedding plants as well as the Veg U Grow range and herb growing packs to UK garden centres.
A Kinglea staff member said: "We don't know what's going on ourselves. We've got another month. Hopefully we will get back on our feet. We do bedding, indoor flowers and vegetable plants but we could end up just doing the vegetables now because that is what is successful."
BDO representative Charlotte Freeman added: "We're trying to sell as much of the business as we can." BDO accountant Rob Davies confirmed that the debt was in the millions but said the business, which mostly sells bedding, vegetable and herb plants to garden centres, continued as normal.
"Plants are going out as normal," he added. "We're looking to fulfil orders going forward. We could potentially split the business."
Creditors include a major seed and young plant supplier believed to be owed £500,000 and a Dutch exporter thought to be owed £2m.