JONATHAN NASH, Holliston

A. The only way you can get rid of it is physical; root it out. Herbicides may help, but they are too dangerous to use. Saturating the plants and roots with salt will also work, but the earth would be contaminated for some time, and salt can get into underground water.

It is Japanese knotweed (Polygonum cuspidatum). Unrelated to bamboo, it comes up in the spring in red spikes, grows to six feet, with big, floppy, and ugly green leaves. In fall it defoliates, leaving you with a whole bunch of bamboolike stems. Amazingly enough, it was imported into this country around the turn of the century as an ornamental.

To root it out, you have to dig down one to two feet to get at the huge, clumpy and tenacious roots. The roots travel underground to spread the plant. If you miss any roots, you will see a few shoots again in spring, but you can handle those with relative ease.

When Jonathan Nash of Holliston asked how he could get rid of Japanese bamboo, the handyman replied that the only real way is to dig out the roots and to keep digging until it is gone, because the roots are deep, clumpy (and heavy), and the plant spreads by its roots. Really miserable stuff, and physical force is the best way, the handyman opined.

But not necessarily the only way, wrote Dr. James Kartell of Chelmsford, a frequent helper in the handyman's eternal search for solutions for beleaguered homeowners.

Kartell had a similar problem and told us how he handled it: ``Dissolve 6 ounces of Round-Up Concrete in a gallon of water and spray the leaves of the plants thoroughly. Repeat in two to three weeks. Voila, goodbye Japanese bamboo forever. No root finding and digging and repeat digging (which I previously got involved in). No toxic residue because Round-Up biodegrades in a few days. It works!''

Leonard Wolfe of Newton had similar thoughts: ``Jonathan Nash does not need a nuclear strike. I have the foolproof way of getting rid of it (that's another way of saying I had it and now I don't have it).

``Let the stuff grow during the summer. Around the end of July or early in August when the growth cycle reverses, spray the leaves with Ortho Kleenup. That is when the plant starts storing energy. The Kleenup is systemic and will slowly go down into the root system. The leaves will turn brown, but next spring about 90 percent will be gone. Continue this process for two, maybe three years, and it will be all gone. Guaranteed.

``The people at Mass. Horticultural told me about Kleenup, and it works to perfection.''

Thank you, both. The handyman usually does not recommend herbicides, but since both those mentioned seem to be safe, then OK. Your ideas are going right into the handyman's dandy electronic file for future reference.

Q. I'm into organic gardening, and I wonder if it's OK to put pressure-treated timbers around a raised garden bed where I plan to grow vegetables. I'm tired of having regular timbers rot out in a few years.

B.K., Worcester

A. Using pressure-treated timbers for this purpose is definitely not organic gardening, and the organic-gardening people, particularly Rodale, would have kittens over this proposal, claiming all kinds of dangers of the chemicals in the timbers leaching into the vegetables. However, the pressure-treated-lumber people would say it was OK, as long as you keep the vegetables about two feet from the timbers.

If you use the pressure-treated timbers, line the inside of them with polyethylene plastic, with the plastic going 6 inches into the earth below the timbers.

Or, the heck with all the controversy and put in standard timbers and replace them every 10 to 15 years.