Where is the clue in Hotton for the Hunt for the Emerald Necklace

The pattern of the orange trees in Hotton's orchard, from top to bottom, go two side-by-side in the top row, then three in the second row, then a space, then three in the third row, then two in the fourth row. You'll find the clue under the middle tree in the second row, which is nearly smack dab in the middle of the orchard.