The number of oak seedlings needed to stock the next stand depends on seedling size and the percentage of oaks desired in the species mix. As a rule, if all the oak seedlings were less than 1 foot tall, you'd need 15,435 per acre. If all were more than 4 feet tall, you would need just 514 per acre. Large seedlings are more likely to survive and outgrow competing vegetation than small seedlings.