QUESTION: I'm having a terrible problem with my tuberous begonias which I grow in containers. The buds drop off before the flowers form. What's the cause?
ANSWER: Bud drop on tuberous begonias may be caused by one of two conditions: either the plants are receiving an uneven supply of water (too much or too little), or they have been subjected to sudden and dramatic temperature changes.
While you can't do much about temperature fluctuations, you can control watering. Set up a regular watering schedule and make regular checks of soil moisture. Although the soil surface may be dry, the soil two to three inches beneath the surface should be kept moist.
Bt Spray Should Stop Geranium Budworms
Q: What are the tiny worms (about one/fourth inch long) that are attacking the buds and leaves of my geraniums and what do I do about them?
A: They are undoubtedly budworms. They can be safely and easily controlled by spraying the plants weekly with a product containing the biological insecticide Bacillus thuringiensis (usually simply listed as Bt). Products containing Bt are commonly sold under the labels Dipel, Turicide and Attack.
Frostbitten Plumeria Unable to Be Saved
Q: Our large plumeria was severely damaged by frost this past winter. There does not seem to be any signs of new growth and when I cut off branches they are dry and hollow. Is there any chance the plant will make a comeback?
A: Sadly, no. Last winter's freeze was particularly severe in your area and if the plant was going to survive, signs of life would have appeared by now. Plumeria plants are subject to damage when temperatures dip below 28 degrees Fahrenheit.
When winter temperatures are expected to drop below this mark, some protection can be realized by tenting the plants with plastic covers. The plastic requires some type of frame so it doesn't come into contact with the foliage. Always remove the covering promptly after danger of frost has passed.
Bartlett Pear Not Suited to Southland
Q: My Bartlett pear tree is large and healthy looking, but it has never produced any fruit. Why?
A: Unfortunately, it probably never will produce fruit. The Bartlett pear tree is not suited to most Southland climatic zones. With the exception of some of the higher elevation areas, the trees do not get enough winter chilling for proper fruit production.
Flash Tape May Keep Birds Off Seeded Lawns
Q: I reseeded my lawn on two different occasions with bad results. Both times birds ate most of the seeds. I placed windmills and large stuffy children's animals on the lawn to keep the birds away, but they were no help. Can you help?
A: There is a new product from Japan called "bird scare flash tape" that has proven effective in scaring birds away. The product consists of mylar coated plastic tape. It is brilliant, shiny red on one side and silver on the other.
Sunlight is reflected off the tape and seems to signal danger to birds. Most experts believe that the birds associate the flashing tape with fire. More information about the tape may be obtained from Modern Agri-Products, 3770 Aldergrove Rd., Ferndale, Wash. 98248.
Where You Can Find Miniature Roses
Q: Can you tell me of any nurseries in Southern California that specialize in miniature roses?
A: Here are four: Pixie Treasures Nursery, 4121 Prospect Ave., Yorba Linda 92686; Nor'East Miniature Roses, Box 473, Ontario 91762, Tiny Petals Nursery, 489 Minot Ave., Chula Vista 92010 and Moore Miniature Roses, 2519 E. Noble Ave., Visalia 93277.
Day Lilies Need Sun to Bring Out Flowers
Q: My day lilies are healthy looking but they don't produce flowers. What is the problem?
A: You don't say so in your letter, but I suspect you have planted your day lilies in a shady area. While the plants will endure in shade, they need at least partial sun to produce blooms.