WhEN DID Nero wolfe hide woman in plant room?

In 'The Rubber Band'.

Clara Fox is being hidden in Wolfe's brownstone when the police arrive with a

search warrent.

In accordance with their plans, she runs to the plant rooms and climbs into one of the troughs used for watering plant in their pots. She is covered with osmundine (mulch like substance), planks are put accross the trough, plants are put on the planks, and - when the police finally make it to the plant rooms in their search

• they find Wolfe and Clara Fox's paramour-to-be (who happened to

be there when the police arrive) spraying water on the plants and discussing horticulture....but they don't find Clara