Q. We were given a beautiful white Christmas cactus that started blooming right after Thanksgiving and continued until the end of January. We had so many compliments from friends that we would like to start some little plants from slips to give to them. Will it hurt the plant to take some tip cuttings? When is the proper time to do so?
Since the buds form in the fall, now is a good time to take cuttings. Make the cut right at a joint, and it can be two or three segments in length. Root in a plastic pot filled with perlite that is kept moist at all times. The mother plant and cuttings will form new growth.
We keep all our holiday cacti, plus cuttings, in a bright but shady spot along the foundation wall of our house. Since all are in active growth during the summer, they should never be allowed to dry out.
They will benefit from a liquid feeding about once a month.
Q. Because of a problem with animals in our garden, we have just installed an electric fence. We've just heard that the red-colored insulators are harmful to birds, but we do not know why. Could you please comment?
The red insulators are dangerous to hummingbirds. Dr. Robert Fuller of the University of Vermont School of Natural Resources reports that the tiny hummers mistake the red for a flower or feeder. Dr. Fuller urges anyone who has electric fencing to use white or uncolored insulators instead of red.
The red ones are to alert humans, but a printed sign would do just as well.
Q. Many thanks for the information on Dictamnus (gas plant). I, too, recall being intrigued by seeing the flame caused by the gas from this plant. Please tell us the catalog name of a perennial that we used to call ''blanket flower.'' The daisylike blooms were reddish, fringed with golden yellow.
We appreciate the kind words that readers have been sending along.
The plant you refer to is Gaillardia. There now are dwarf varieties as well as tall.
Q. Slugs are going to devour everything in our garden if we don't do something soon. We have seen some that are six inches long when stretched out crawling up the side of our foundation at night.
We do not doubt your measurements. We look for slugs at night with a flashlight and dispose of them in a can of household bleach. You can set the pans of bleach near your plants, but they should be deep enough (about 4 inches) so the slugs don't crawl back out. White vinegar also works well.
Some people have success with grapefruit skins inverted among the plants; you can dispose of them the next day. Also, boards laid in rows invite the slugs toward cover at daybreak (they are night marauders) and they can be then scraped off during the daylight hours.
There are good chemical baits (poison) in garden stores, but be sure they are not placed where animals and children will find the pellets. A practical place to put them is under boards.
Q. We planted ornamental corn right next to our sweet corn. Now friends tell us we should not have done this as the pollen from the ornamental corn, falling on the silks of the sweet corn, will adversely affect the taste. What do you say?
This would be true if both varieties of corn had the same maturity date. However, most ornamental corn takes from 105 to 110 days to mature. As a result, it forms tassels (pollen-producing structures) much later than most varieties of sweet corn.
Incidentally, corn will not produce well if only one or two rows are planted. It might be better to have three or four short rows than one or two long rows so the pollen will be circulated back and forth over the silks.
Each silk is attached to a kernel and must receive pollen in order for the kernel to develop. The number of days to maturity is found in seed catalogs and on the packets themselves.