How can I control this invasive plant?

Asked September 25, 2015, 6:23 PM EDT

Please identify the plant in the attached photos. This showed up in my driveway by the road several years ago. Can you tell me where I can find information on how it reproduces too? It seems as though you just see the tiny red leaves coming up and then the plant is inches around in no time. I see one flower, pull them up or spray (Roundup, Crossbow) and they just keep spreading like wildfire.

Benton County Oregon weed issues plant identification lrk horticulture

1 Response

Hello there and thank you for using Ask an Expert. I have been fighting this weed in my vegetable garden for several years. It is common purslane or portulaca. This weed is very invasive and difficult to deal with. There are several things you can do to rid yourself of the weed or at least get it under control. First you must deal with it as soon as you notice the seedlings emerging. It is very fast growing and it is essential that you rid yourself of the weed before it produces more seeds. Seeds are spread by the wind and can come onto your property from plants or soil you bring to your place. From seedling to mature seed can occur in about three weeks. A mature plant can produce over 100,000 seeds in a season. I pull them by hand as soon as I see them start to emerge. The young plants are most susceptible to herbicides. Be sure that you use an herbicide that is labeled for use on purslane (portulaca). When weeding by hand you need to remove as much of the weed as possible as they can grow again from a portion of a stem or a root. Do not throw them on the compost pile. Additionally you must remove them from the soil once they are pulled as they can resprout after pulling if left in contact with moist soil. I carry around a five gallon bucket and throw them in there as soon as they are pulled. I let them dry out and then throw them in the garbage. Unfortunately seeds can survive in the soil for years. Even with meticulous weeding, chances are that you will be dealing with this thing for a while. Mulch can help tremendously. The mulch must be applied at least three inches thick. As you say this is in your driveway additional gravel could be the key for you. Don’t drag your gravel as this will bring more seeds to the surface. The seeds must be deprived of sunlight so they can’t germinate. I got my purslane under control by covering my vegetable garden with black plastic. I still get seedlings but I deal with them as they emerge and I have fewer each succeeding year. Another method is to solarize the affected soil. Cover the affected area with clear plastic when the soil is moist and the sun at it strongest over the summer for 4 to 6 weeks during July and August. This method is called solarization and will kill plants and other seeds in the soil also. Avoid tilling soils prior to solarization as that can bring up more seed from below the soil surface. This plant is also edible. It is occasionally for sale at our local Farmer’s Market.