Are You a Master of Mulch? A Scholar of Sweet Box? Prove It.

b) Hardy orange ( Poncirus trifoliata).

c) Virginia sweetspire ( Itea virginica).

13. Of the following plants that offer fall fragrance, which is a native?

a) Elaeagnus.

b) Osmanthus.

c) Common witch hazel.

14. When do you perform hard renewal pruning on broadleaf evergreen hollies?

a) Last week of February.

b) First week of May.

c) Middle of October.

15. Compost should never contain which of these organic substances, especially in urban areas?

a) Shredded paper, seeds and seed hulls.

b) Chicken guano, horse manure and coyote urine.

c) Cooked food, meat and diseased plant material.

16. What plant family feeds about one-third of the world's population?

a) Legume.

b) Cabbage.

c) Grass.

17. What has proven an excellent tree to line city streets?

a) Katsuratree ( Cercidiphyllum japonicum).

b) Goldenchain tree ( Laburnum X wateri).

c) Hophornbeam ( Ostrya virginiana).

18. What four conditions do seeds need to sprout?

a) Light, heat, fertilizer, water.

b) Light, heat, soil, water.

c) Light, heat, air, water.

19. When is the best time to prune deciduous trees?

a) During dormancy, after leaves fall and expose branching habit.

b) Before flowering or immediately after new growth in spring.

c) When they have grown so large that they need major pruning.

20. When should deciduous shrubs be pruned?

a) Generally, after flowering.

b) Spring-flowering shrubs in fall.

c) Fall-flowering in spring.

Joel M. Lerner is president of Environmental Design in Capitol View Park, Md. E-mail or contact him through his Web site,http://www.gardenlerner.com.