Donnybrook's orchards line the Preston River valley north and east of the town. Several growers run pick-your-own days during the apple harvest (roughly March to May), with stone fruit and pears earlier in the summer. Even outside picking season, farmgate stalls sell apples, jams, juice, and cider — quality is consistently better and prices are lower than anything you'll find back in Perth.
The simplest approach is to drive a slow loop on Bridge, Preston, and Mumballup roads east of town and stop at whichever stand looks busy. Bring cash; not every stall takes cards.