Flowers buds drop off. Too much water or high temperatures. Improve drainage when soil is too wet. In overly high temperatures mist the plants in the morning and mulch the roots to keep them from drying out. To prevent this use only sterilized soil.
Seedlings topple over as rot affects stems at soil level.
Use only sterilized well drained soil. Avoid crowding of seedlings and cuttings. Bulb Dust applied lightly to the soil may prevent this disease from happening. Water to wet soil but do not soak or let stems stand in water. When using pesticides always read the entire label on the container and follow the directions.