Althought a variety of insects and diseases have been found on these popular annuals, few are serious, for wax begonias are virtually trouble-free, easy-to-grow plants that require only minimum attention.
Buds Sometimes Drop Off
Drainage - This is not an uncommon problem with begonias. If flower buds drop off before they open, it is often a sign that the plants are growing in poorly drained soil, and/or that they have received too much rain or watering. This does not mean that the soil should not be watered, for dried out soil also can cause dropped buds (they get you coming and going). The best way to prevent such problems is to deal with the soil over time. Add plenty of organic materials to the soil every chance you get. This vital addition will allow the soil to soak up more water and nutrients while enabling it to drain well – pretty cool, heh?
Too Much Heat - Begonias exposed to high temperatures for extended periods of time also will sometimes drop flower buds. For this reason, begonias grow best if they are not exposed to hot, midday sun. During hot spells, spritz plants in the late morning and, if possible, water at noon to cool the roots. Mulch also helps keep the roots cool.
Here are some symptoms of some of the problems you might occasionally find
| Problems of Wax Begonia | |
|---|---|
| Symptom | Probable Cause |
| Leaves Wrinkled or Curled; Discolored, Stunted, Tend to fall off | Aphids |
| Black powdery sooty mold fungus forms on honeydew; plants may die if problem continues | Aphids Herded By Ants |
| Oval, white insects; leaves deformed, discolored; leaves shiny, sticky | Mealybugs |
| Leaf blotches, leaves curl, wither, drop; plant stunted | Leaf Nematodes |
| Ragged Holes in Leaves | Slugs And Snails |
| Leaves stippled, yellowing or bronze; dry out and drop may be webbing visible | Spider Mites |
| Leaves and Petals Are Pale; Silvery | Thrips |
| Weakened plants; yellow leaves; leaves discolored; covered with honeydew | Whiteflies |
| Brown Spots on Leaves, Grayish Mold Forms on Tissue, Gray Mold on Flowers, Leaves, Stems Soft, Rotted | Gray Mold, A Fungal Disease |
| White Powder Coats Top of Leaves | Powdery Mildew, A Fungal Disease |
| Plant actually disappears | Deer |
