Magnolia 'Little Gem'-easily controlled to te 2.5-3m height range that suits your requirements ben. Will generally form a clipped block of foliage over time though not as dense as the lilly pilly we chatted about. *Could be used as a "pleached" hedge(stripping the trunk of foliage and promoting foliage on the top half of the plant) so that a second tier of plant material can be included underneath for a more dynamic visual aesthetic.
Little Gem Magnolias are a great late spring and summer bloomer. With fragrant flowers, they are sure to fill any garden with sweet smells of summer. Little Gem Magnolia maxes out at 20x20 and is slow growing. They do like more water than most landscape plants, but we believe it is worth it for such a beautiful show and sweet frangrances!