Christmas preparations begin this weekend for readers with holiday cactus and poinsettia plants. Much has been written and said over the years regarding the fall care programs for these plants. Unfortunately, not all the information was accurate, as thousands of homeowners learned from personal experience.

They followed programs to the letter, but nothing happened. If you've been disappointed in the past, give these programs a try and write me after the holidays when you score a perfect bull's eye with your festive plants.

First, let's examine the poinsettia.

If you still have the poinsettia from last Christmas, it proves that you have a soft spot in your heart for plants. However, there's no reason to hold out any hope for the poinsettia to flower again. No matter what you do, the extent of flowering will be poor compared to the plant's performance a year ago. Some leaves (actually bracts) will color, but it's going to be a wasted effort by garden standards.

Instead of keeping the poinsettia going for the past 10 months, you should have taken leaf-and-stem cuttings in February, May and August to propagate dozens of new poinsettias, each of which will color if you artificially create short days and long nights for the plants.

If you did nothing and only have the "mother" plant, leave everything as is. Continue your care program. Leave the plant in bright indirect light, keep the soil barely moist, and eventually some of the leaves will color in mid-February. However, if you took cuttings in the spring and summer, you're ready to force the new poinsettias to color for the holidays.

The daily scenario is nine consecutive hours of full sun or bright indirect sunlight at average room temperatures, followed by 15 consecutive hours of total darkness at room temperatures from 61 to 64 degrees. Meanwhile, keep the soil lightly moist and apply Peters' 20-20-20 every two weeks.

For most readers, the total darkness requirement is the stumbling block. Here are some practical suggestions for overcoming the problem:

First, use three black plastic trash can liners, one inside the other, and draw them over the plant. Begin by placing the plant in a cardboard box, drawing the liners over the entire assembly, and moving the plant to a dark place where lights will not be turned on at night.

Second, take a trip to the supermarket in search of three cardboard boxes, each one larger than the next. Boxes must be light-tight, of course.

Start with the largest box on the floor and place the smallest box inside the big one. Put your poinsettia into the small box, then invert the intermediate box and place it over the small box housing the poinsettia. This closeting of the plant provides absolute darkness for the required 15 hours each day.

If you start darkening the plant this weekend, the routine will continue until the Dec. 5-6 weekend, by which time you'll see the cyathia (minuscule yellow flowers) starting to develop. Leaves will color up well for Christmas.

Even if you achieve total darkness, the plant won't cooperate unless the air temperature hovers between 61 and 64 degrees during the darkness cycle. Don't guess that the temperature is within these boundaries. Know for sure by using a thermometer.

Where do the commercial nurseries stand with poinsettias?

Because extraneous light sources around greenhouses can be controlled, many nurseries have stopped using black cloth in the greenhouse to create the darkness required for poinsettias. Not only are nurseries conditioning their plants earlier (mid-September), but new hybrid poinsettias (V-10 and V-14 cultivars) are also not as sensitive to light sources as plants have been in prior years. The ultimate research goal is to create a poinsettia that colors up without any need for darkening.

Turning to the holiday cactus, move onto the new care program this weekend if you want flowers for Christmas. This applies only to cactuses that summered indoors or were moved indoors prior to Labor Day. If plants remained outdoors at Labor Day and beyond, those cactuses will flower in the next four weeks. Check the plant closely and you will find the tiny flower buds starting to swell.

With plants indoors before Labor Day, here is the care schedule:

During the day, the cactus should bask in full sun or bright indirect light. In the evening (no set time), move the plant to a cool location, since exposure to lower temperatures triggers the formation of flower buds. I suggest moving the cactus to the floor of the enclosed garage sometime each evening, returning the plant to the sunny window the next morning. Continue this routine daily through the first weekend of December, then leave the cactus near the window.

By Halloween, when freezing temperatures invade the garage, relocate the cactus to a shelf so that the plant is no longer exposed to frost. By raising the plant well above the floor, the plant won't be killed by frost. If you lack a garage, chill the plant each night on the basement floor away from any heat sources.

All the while, water the cactus religiously every two weeks. Use warm water, flooding the pot in the sink so the root ball is thoroughly moistened. Don't let the pot stand in a saucer of water.

Up to early December, fertilize with 15-30-15 every four weeks. By the Dec. 5-6 weekend, water the cactus weekly to relieve stress conditions. Flowers should open Dec. 20-22 and last until a few days after Christmas. To extend the life of the flowers, move the cactus to cooler room temperatures over Christmas.

Turning to the outdoor garden, this weekend marks your fourth and final fall feeding of the lawn. Rely on 10-6-4 inorganic, applying five pounds for each 1,000 square feet of lawn area. Assuming that you are mowing this weekend, cut first and then fertilize. Soak the lawn thoroughly if no rain is in the immediate forecast.

Looking ahead, plan on applying potassium sulfate (0-0-50) to the lawn over the Halloween weekend to relieve stress conditions on the lawn. The rate is four pounds per 1,000 square feet, the equivalent of applying two pounds of potash over the same area. On the rotary Cyclone or Spyker, use setting 4; with the Scott drop spreader, use setting 4 3/4. If no rain is forecast, soak afterward.

If you're checking your lawn, don't be shocked to find some nuisance weeds sprouting -- henbit on the south lawn and chickweed on the north. These weeds will sprout randomly all fall and winter, so make the first of several spot treatments toward mid-November. One application puts the weed away, but seeds that sprout every now and then cause problems.

In the "leave well enough alone" department, don't prune grape arbors or hydrangea and don't dig up the Dusty Miller bordering the bedding garden. Dusty Miller will be pruned to the ground before Christmas, only to spring back to life next April.

With the bedding garden in limbo (or mighty close to it), don't you wish you could get your hands on a few dozen ornamental cabbage and kale plants to accent the fall and winter garden? Maybe garden shops will stock the plants next year so that when frost devastates the bedding garden, these colorful plants may be planted.

If your travels take you to Williamsburg, you'll find ornamental cabbage and kale accenting the campus of the College of William and Mary. The college does an outstanding job of gardening for the fall and winter; if it works for the college, it'll work for us. Jack Eden hosts "Over the Garden Fence" Sundays from 10 a.m. to 1 p.m. on WTOP Radio (1500 AM).