Weeds in pavers

Image: Brand X Pictures/Home and Garden/Alison Miksch

I resurfaced my large driveway with interlocking pavers a number of years ago. Ever since then I have been plagued with weeds of all sorts. Some appear to be coming from seed, others from underground roots. What can I do? I don’t want to spray.

Conway Lum, Plant problem and pest expert

Investigate using heat to control the weed problem. This can range from pouring hot water over the weeds to obtaining an infrared heating unit powered by propane. The infrared heating units only need to touch the weeds to inflict damage, but because there is no flame, they can be used close to other plants and any surfaces from wood to concrete to asphalt. Either method is environmentally safe.

You can try non-selective organic herbicides, but they may kill or damage any green plant they come in contact with, not just the weeds you’re after. These organic products contain ingredients such as fatty acids (derived from man-made soaps) or acetic acid (derived from vinegar). As with all herbicides, read the label and follow directions for use carefully.