Jack Frost has already visited the gardens of most readers. All good things must end and gardening is no exception. In the book Ecclesiastes it says, ". . . a time to plant, and a time to pluck up that which is planted . . . ." Now is the time to pluck up those summer bulbs! They need not be dug prematurely, but do not wait until the soil is frozen and attempt to dig those bulbs.

The most common flowering "bulbs" are really not bulbs at all. Dahlias, cannas, gladiolus and begonias are tubers and corms.To preserve dahlias, dig the plants after they freeze, then clip off the stems 3 inches above the tubers. Carefully remove the soil from the tubers and let them dry for several days in a warm, dry location. I preserve mine by placing the entire root in a box or other container, with a covering of shavings, sand, sawdust, vermiculite or peat moss. Totally cover the tubers to keep them from drying out. The containers must be stored in an area above freezing temperatures. It should not be too warm because the tubers will start to grow.

Excessive drying is sometimes a problem. To avoid this problem, place a plastic cup full of water inside the box. The tiny amount of water that evaporates from the cup will provide enough moisture to keep the tubers from drying and shriveling. Check the tubers' condition at least monthly to make sure they are not decaying or shriveling.

Meticulous gardeners with less storage space may want to divide the clumps right now. Separate the clumps with a knife so that each tuber had at least one eye to produce next year's plant. Label the tubers with a water-proof marker to show color or variety name.

Tuberous begonias also must be dug. Cut off the stems after the first frost and remove the soil from the roots. Leave them in a warm, dry place, secure, and then separate the tubers. Cover and store them the same way as dahlias.

Cannas can be dug and stored the same way as dahlias. Cannas usually don't shrivel in storage, so they won't need supplemental moisture.

Gladiolus are much easier to care for. As the tops turn brown, clip off the leaves and dig the corms. Clean the soil away and separate the corky remains of last year's corms before placing them in storage. Many glad fanciers soak the corms in a solution of lindane or Orthene for 20 to 30 minutes and then air dry them before placing them in storage. This kills the over-wintering thrips that damage the blossoms each year. Glads can be stored in cardboard boxes without covering materials. They also store well in mesh onion bags. Store in cool, dry locations where temperatures do not get well below freezing.

There are many other beautiful plants in the garden you may want to save for next year. Choice geraniums can be over-wintered if given a little care. I prefer to dig the large plants and pot them up in potting soil. Move them into a cool greenhouse or sunny window to keep them through the winter. If you don't have that luxury, pot them in a well-drained soil and place them in a location with some sunlight, such as a basement window.

Cuttings can also be taken from geraniums and rooted to provide plants for next year. Make cuttings about 5 inches long from tips of desirable varieties. Remove all except the top three or four leaves and let the cuttings dry for 24 hours to prevent decay. Choose a well-drained rooting medium such as coarse sand, perlite or vermiculite.

Geraniums need light and warm soil to form roots. After roots have formed, plant them in individual pots to carry them through the winter. Be very careful not to overwater them. With low temperatures and very low light intensities, the plants use very little water. In my opinion, other options such as digging geraniums and hanging them upside down in the cellar don't work as well, but some gardeners have success with this method.

I also keep purple fountain grass through the winter. Dig the large clumps and cut them back to 8 inches. Plant them in pots and water only once per month. The plants go dry and dormant but will regrow when repotted next spring. If you have a greenhouse, you can divide and replant them now.

If you don't want to leave all of the other plants out for Jack Frost, consider digging some impatiens and fiberous begonias. Impatiens are known as "blooming idiots" and begonias flower freely if they have enough light. Place these plants in a warm, sunny window and their colorful flowers will give a welcome lift to sagging spirits on cold, dreary days.

When any plant is moved from the outdoors to the inside, it is a good idea to spray them with an insecticide to control those stowaway pests looking to spend the winter in a warm environment while munching on your houseplants.

Malathion or pyrethreum are excellent sprays to control most pests or simply give them a shower with insecticidal soap to wash away those unwanted creatures. Don't miss the underside of leaves with the pesticide.

A little effort now will pay big dividends when you plant your garden next year. Dig your summer bulbs and propagate your next varieties for next year. If you overlook this task, you'll miss the ". . . time to pluck up that which is planted . . ." and you'll be paying for new plants next year.

- THE UTAH ORCHID SOCIETY presents "A Cascade of Colors" at Trolley Square Oct. 20-21. The exhibit will be open to the public Saturday and Sunday from noon to 6 p.m. For further information, contact show chairman Shawn Quealy, 466-2979.