The plants which Teddy put in the trough were known as 'cut and come again' salad leaves which meant that instead of waiting until the plants turned into big lettuces, the bears could cut off some of the outside leaves, taking exactly how much they needed for their salad or sandwich, and then leave the rest for another day.
It took Teddy ages - he made a hole for each plant, pushed the plant out of the seed tray, and popped it into the hole, being careful to push the compost back around it.