Recently I bought a pot of Stars of Bethlehem (orange) as an indoor plant. It has finished flowering and the leaves seem to be withering. Please advise if I can plant the bulbs outdoors, if they can survive the cold winter,and the growth requirements. I live in the Thornhill area.
There are a number of plants which have the common name Star or Stars of Bethlehem. As your plant has orange flowers I think is is Ornithogalum dubium, which is sometimes call Star of Bethlehem and is also called orange star flower, snake flower or chincherinchee. This plant is a South African bulb which, unfortunately, is not hardy outside in the Toronto winters. (It is hardy in zones 7 through 11 and would be fine outside in a Vancouver winter). You could, however, grow it outside in a container during the summer provided you bring it inside for the winter.
Typically, after flowering, the leaves of this plant will continue growing (and feeding the bulb) until late summer, at which time they die back. However if your plant’s leaves are withering just following flowering I suggest you repot the plant. This will allow you to check if it is root bound. This is also the time to apply a fertilizer suitable for houseplants, which you can get at your local garden centre.
In late summer, when the leaves die back, your plant should be allowed to go dormant. The leaves can be cut back to the soil and plant kept dry for a few months. In the fall you should start watering again. Make sure that the plant is in a pot with good drainage and do not over water. How much water you use will depend on whether you have slow or fast draining soil. The goal is to keep the soil slightly moist during the fall, winter and spring growing period. It is important that the plant is not over or under watered as this can damage the bulb.