I love spring-flowering bulbs, but I was wondering if violas are the only spring annuals for our area. For the period before our frost-free date, I would like to try something else for color that will fade out with the heat and need a summer replacement.

Violas and pansies, related but separate species, are the kings of cold-tolerant, early annuals. Violas are a more petite plant, producing smaller but abundant blooms. They also reseed, as evidenced by a long-time favorite, Johnny jump-ups. The cute purple and yellow blossoms pop up anywhere. Pansies are actually biennials or short-lived perennials in Michigan and have become the darlings of hybridizers for unusual color combinations. They mix well with the spring bulbs, such as daffodils, tulips and hyacinth varieties.

A few early, cold-tolerant annuals you might not have guessed are sweet alyssum, stock, snapdragons, dianthus, forget-me-nots, sweet peas, calendula, and lobelias. Start them in pots indoors or purchase hardened stock from your favorite greenhouse. Then nestle the sprouting pots in small clusters into the soil amongst your flowering bulbs. Surrounding them with soil protects and insulates their roots from freakish cold snaps. The refreshing color jazzes up the traditional spring bulb show and lends interest and texture to the overall display.

I have a three-year-old African violet that is watered and fertilized regularly, yet it has never flowered. It is in a west-facing window. How do I get this plant to bloom?

There are several reasons your African violet might not want to bloom. Let’s examine the “perfect” conditions for African violets and you can check them against what you are currently providing. The most important factors are light, pot size, soil, water and fertilizer.

Optimal light is the cooler morning sun from an east window with the plant located twelve inches or less away. They can take the hotter west window, just watch them for wilting or have a sheer curtain to block the hot summer and cold winter temperatures. They need 12 to 14 hours of bright, indirect light. An easy way to tell if your plant is getting enough light is to look at the leaves. If they reach for the light and have long upright stems, they need more. If they lay nice and flat on the pot they are happy. If you don’t have good windows, they grow easily under artificial “grow” lights with full spectrum bulbs placed 12 inches above the foliage for at least 12 hours a day (use a timer).

Temperatures should be between 70 and 75 degrees, although a cooler windowsill in hot (west or south) windows can work. Avoid drafty windows and doors or locations near heating and air conditioning vents.

African violets like to be consistently and evenly moist, but not wet. Watering from the bottom is a good technique, as is keeping the pot inside another pot. This insulates the plant from hot temperatures if it’s in a west window and allows it to wick up water from the deeper pot. Try to water with room temperature water and use fresh rain or spring water. Any water not absorbed by the soil within about 30 minutes should be poured out. If you water from the top, water carefully under the leaves and don’t splash the leaves. Too much water will lead to crown rot and too little will cause the leaves to wilt and invite pests.

African violets are heavy feeders (since they are shallow-rooted) and like fertilizers formulated especially for them. Most brands are recommended for use with every weekly watering. A fertilizer with a 12-36-14 formulation is good for bloom production (the middle number represents phosphorus, which is for healthy roots and blooms).

Small, tight pots, especially non-porous types like plastic and ceramic are best, but whatever you use must have a drainage hole. A plant with a 12-inch spread can be happy and bloom in a 4-inch pot (the rule of thumb is to use a pot with 1/3 to 1/2 the size of the plant spread). Make sure there is only one plant per pot. Sometimes African violets send out suckers; cut these off immediately.

A loose soil mixture with great drainage is essential to allow the small roots to penetrate. You should be able to easily push your finger into the soil.

Dry air is another possible reason your plant doesn’t bloom. They like 50 percent humidity. Place an open saucer of water next to the plant, or set the plant on a tray filled with pebbles and water. The pebbles keep the plant’s “feet” dry.

Removing spent blossoms (the entire stem) and dry or diseased leaves (carefully) will keep your plant happy. If you like a symmetrical plant you can remove a couple of outer leaves that ruin the circular appearance of the plant. Some experts say this also helps stimulate blooms.

Finally, according to the African Violet Society of America, if nothing else works, a bit of a shock can induce an African violet to bloom. They suggest tapping or squeezing the pot. Another way of shocking the plant is to withhold water until it wilts, then water. This is not advisable more than once because it can weaken the plant and invite pests.

I recently read that a 1 to 2 percent caffeine solution is a possible way to kill slugs. I know that coffee grounds themselves repel slugs, but what about the caffeine solution? How exactly does one make a caffeine solution of 1 to 2 percent?

The toxic effect of caffeine on slugs was inadvertently discovered by a biologist in Hawaii, Earl Campbell, now with the U.S. Fish and Wildlife Service, and Robert G. Hollingsworth, an entomologist with the U.S.D.A. Agricultural Research Service. Campbell was seeking a “silver bullet” solution to some tiny nonnative Caribbean frogs that hitched a ride on a ship and disembarked in the Hawaiian Islands.

These frogs are unbelievably noisy. Their mating calls go on all night and year-round, reaching 90 decibels. Note that OSHA requires workers to wear protective hearing devices at 85 decibels. So at this volume, sustained exposure to these irritating vocalists can produce irreversible hearing loss. Since the mid-1980’s, Hawaii’s alien frog populations have been rising exponentially, while the rest of the world populations are declining or becoming extinct. By sheer quantity and volume, the amphibians were now a health hazard and an ecological nightmare.

Campbell’s group began working through various off-the-shelf grocery products, trying to find a legal but readily available product to target the frogs. They found a caffeine-rich, anti-sleep preparation that worked at the product label’s recommended level. He got permission from the EPA to field test a dilute concentration of the compound on soil in greenhouses. As soon as Campbell anointed the soil with the caffeine solution, he unexpectedly discovered that slugs began surfacing and dying.

Hollingsworth became interested from a pest control perspective. Small snails chewing away at the roots ruin tropical ornamentals such as orchids. Hollingsworth tested various concentrations of dilute caffeine against the orchid snails. A 4-ounce solution of 2 percent caffeine devastated most of the garden slugs. Even a .01 percent solution killed a significant number.

The bottom line: caffeine makes a good botanical pesticide. According to Hollingsworth, the reason slugs and snails are so susceptible is that they have no exoskeleton to protect them from coming in contact with a water-based solvent. “The mucus, which is the basis for their locomotion, is very high in water content,” Hollingsworth noted, “and permits the water-soluble caffeine easy entry. Once inside the critters, the neurotoxin destabilizes the mollusks’ heart rate.”

Coffee tends to have a caffeine content of about 0.1 to .05 percent, so it should be somewhat effective at killing slugs in your garden. It won’t hurt to pour coffeepot leftovers on the soil around your hostas. Even the grounds lightly sprinkled over the soil surface will deter them and might also cause a toxic reaction. While it isn’t feasible at this time to make a 1 to 2 percent caffeine solution at home, anti-slug products containing this concentration might be made available in the future.