Mock Orange

Q. Our mock orange was planted 3 years ago in the full sun and has never bloomed with any beautifully fragrant flowers. Could you please tell us what to do to get it to flower this coming summer?  When we purchased it from a well-known gardening center in our area we were told that the bush was 2 years old and should bloom for us.

A. Mock orange (Philadelphus species) thrive in full sun or light shade in almost any soil but do best in moist but well-drained soil supplemented with peat moss leaf mold or compost. Probably the reason that your plant has not bloomed is a lack of pruning. Mock orange needs to be pruned immediately after flowering by cutting back the outer stems that have flowered. Each cut should be made just above a strong outer facing bud or new shoot. Next years blooms will appear from these buds.

The first year you will see no flowers the second some but by the third year you should have it in nearly full gorgeous bloom. It is the pruning and fertilizer.

Have you tried adding phosphorus to the soil? Bone meal or a commercial preparation for flowering plants/shrubs that has a high phosphorus level (the middle number in the ratio label for nitrogen phosphorus and potassium) might help. Also if someone is pruning the mock oranges you will want to wait until after bloom time. Pruning the bushes in the spring before blooming time will be shearing off the flower buds.

It's been suggested to me that they do not like being near a cement foundation of a house just under a window. But I assume that is not your problem as you stated it got full sun.

Mock oranges bloom on the previous year's growth so you should only be pruning immediately after they bloom. I've read where some mock oranges fail to bloom for as long as five years or more. If the plant is otherwise healthy and in full sun (and you're pruning correctly) there's not much more you can do except wait. Best of luck!