Herbicides can be safely used around pets if they don’t touch it when wet

We had a landscape designer out to our house last spring to do an estimate on a complete makeover of our front and back yards.

At the time, the yards were full of what we thought were regular weeds. However, the designer told us the weeds are oxalis and that it would need tobeeradicated before she could give us a quote.

Since then I’ve read about oxalis and apparently it is very difficult to get rid of. Although our yards are now mostly bare dirt, we know the oxalis will return when the rains come. We are thinking of hitting it with Roundup, but we have two dogs and worry about their health and safety.

Our three questions for you are:

• Would Roundup work to kill oxalis for good?

• If yes, would the dogs be safe if we removed them from our property while the Roundup dries?

• Is there an effective alternative to Roundup?

— Mary Parsons, Mountain View

I hope you are looking for a new hobby because hunting down and eradicating oxalis will give you something to do for a very long time.

I don’t want to get into the debate about whether Roundup causes cancer (Bayer just settled a $10 billion lawsuit about that in June), but experts say it is safe to use around pets as long as they don’t come in contact with it while it is wet, and it is safer than some other herbicides. Be sure to keep the dogs indoors, and pick up any chew toys, food and water dishes and other items that might accidentally get sprayed and that would then come in contact with your dogs.

That goes not just for Roundup, but for any herbicides. Because of their potential to sicken your pets, they should be used only as a last resort. However, neither Roundup or any other variety of broad-leaf herbicide is likely to do much good against oxalis.

Oxalis spreads in two ways:

• It produces seeds in pods that look a bit like miniature okra. The pods break open and shoot out the seeds.

• Oxalis spreads through a system of interlocking rhizomes that produce tiny bulbs called bulbils. The devious part is that if you pull up the plant, you break off rhizomes, which then just produce more rhizomes and bulbs. In fact, the plant counts on this to ensure its survival.

That means the only real way of getting rid of it is to dig it up and find each and every piece. Gardeners who have done this say it can take three years to completely eradicate oxalis and then they must be forever vigilant in case one sneaks back in.

Herbides will kill the portion of the plant you can see, but it won’t kill the rhizomes and bulbs. Sheet mulching can be helpful in that it requires the weed to use more energy to push itself out of the ground, which depletes the bulb. It also improves your soil’s health, and believe it or not, oxalis would prefer to grow in our hard, clay soils.

Dealing with weeds can be frustrating, but don’t let it force you into rash acts. Just as you are doing now, think of the pets when taking action.