Ask the gardeners

I am very fond of iris but the ones we have bloom only once a year. Last fall , in a public garden, we saw iris blooming and the caretaker said they bloom twice a year.

How can I get our iris to bloom twice or for a longer season? Would feeding help?

Feeding won't make your iris rebloom. However, environment coupled with genetic makeup can give you blooms twice a year and in some areas three times. They are called ''remontants,'' something hybridizers have brought about in the last 10 or 12 years. There are now more and more listed in the catalogs, so look for them.

For iris to rebloom, they need full sun, plus a rich soil, high in organic matter, plenty of water if soil begins to dry out, and a long enough growing season.

Interestingly, New Jersey and Ohio now have fall iris shows. For more information write to: Reblooming Iris Society, c/o American Iris Society, 2315 Tower Grove Avenue, St. Louis, Mo. 63110.

Is it true that egg shells soaked in water will make African violets bloom?

The egg shells might help (many folks vow they do) but failure to bloom is usually due to several factors, such as insufficient light, too high or too low a temperature, nutrition, soil mixture, soil too wet or dry, etc. The main nutrient in egg-shell water is calcium.

We suggest you check all the above reasons for non-blooming. If you feel it is lack of fertilizer, apply a balanced one according to directions. Balanced means it has nitrogen (N), phosphorus (P), and potassium (K) in it. The analysis is on the label.

Our apple trees haven't had any fruit for the past two years. An old-timer in town says to sprinkle rusty nails around the trunk and to pound some nails into the tree. Will this work?

No, apple trees don't need iron for fruit formation and the rusty nails wouldn't provide it even if they did.

It sounds to us more like a lack of the right pollinators or spring frosts.

We've been plagued by all kinds of insects on our flower bed this summer. Isn't there an all-purpose spray for us ordinary ''dirt dobbers''? No toxic chemicals, please.

One product that works well for us is a combination of Tabasco sauce, detergent, and alcohol. We've eliminated whitefly, aphids, and spider mites with only one application.

We use 1 teaspoon of Tabasco, 1 teaspoon of liquid dishwashing detergent, and 1 cup of rubbing alcohol in a quart of water. Caution: Be careful not to breathe the fumes and do not spray if there is any breeze. It is hot to inhale. Some folks wear a mask.

If you apply it to edible crops, be sure to wash thoroughly after spraying or the crops will taste hot. And we mean hot!