|My tuberous begonias are planted in pots. They seemed to be doing well, the soil is a mixture of potting soil and peat moss. They have recently developed yellow streaks on the leaves, though the plants still appear healthy otherwise and are developing blossoms.|
|Some begonias have variegated leaves, but if yours aren't of that variety, there could be a problem. Many things can lead to yellowing leaves: Are your begonias in a shady place? They are best adapted to shade, and excess sun can cause shade-lovers to form pale leaves. Inadquate moisture is another possibility - begoinas love a humusy, moist, yet well-drained soil. Avoid sprinkling water on the leavs, since this can invite fungal and bacterial diseases. Viral infections somtimes show up as streaks in leaves, as do some nutrient deficiencies. |
Begonia leaves will yellow in fall as the tubers go dormant, but that's a ways away! I hope this information gives you some clues to the cause and possible solutions. Let us know if you need anything else!