Hibiscus plants can be overwintered indoors
Question: What is the best way to save hibiscus plants over the winter• Can we keep them under a grow light and, if so, how?
Answer: There are several ways to winter over tropical hibiscus plants, all of which should be done before we get a frost. The first is to simply move the hibiscus indoors, place it in a sunny location, water it every week or two, and wait for the spring. If you choose this method, be aware that aphids, scale, mealybugs and other pests may piggyback their way indoors. Check the stems and leaves of the plant regularly during the winter months and treat with insecticidal soap as necessary. If your hibiscus is too big to move indoors, feel free to prune it back a bit before moving it inside.
Another method is to move the plant into the garage (one that doesn't dip below 40 to 45 degrees) and let it go into partial dormancy. All the leaves will soon drop and you might think the plant is dead, but it isn't. Water it only very sparingly every month or two and re-pot it in the spring, gradually moving it into warmer and higher light conditions over a period of a month before putting it outdoors.
The third option is to place the hibiscus under a grow light strung from the ceiling with adjustable chains. The light should remain only a few inches from the plant top and should be on for a minimum of 16 hours per day. Again, watch for piggybacking pests.
Whichever method you use, be forewarned that a few weeks after moving the plant indoors, all the leaves will drop. Over the course of the following few weeks, new leaves develop (except when using the garage/dormancy method). This new foliage is better adjusted to the lower light levels, lower humidity and warmer temperatures of the home.
Q: My daughter planted three sunflower plants this past spring. The plants did well for a couple months, then died. She kept them watered to no avail. Should they be planted in the fall?
A: Sunflowers are annuals and, although you can throw down some seeds in very late autumn, it's best to wait to plant them until spring. I, too, have been tempted to buy potted sunflowers grown out at my local nursery, but although they are lovely, these greenhouse-grown sunflowers are not your best bet for long-lived, prosperous plants; those come from seed started directly in the garden.
Sow sunflower seeds in mid-May according to package directions. There are literally hundreds of varieties of sunflowers on the market, so pay attention to both flower color and height. I find branching varieties to be the top picks for my own garden. Rather than producing one gigantic flower, these varieties produce many flowers per plant and do so over a longer period of time; and they are great for cutting. My own personal favorites include Lemon Queen, Bashful, Indian Blanket, Soraya and Chianti.