The common purslane (Portulaca oleracea) is an annual succulent that grows all over the world.
Purslane is generally considered an exotic weed, despite the fact that it has certain applications where it is intentionally cultivated. If you aren’t using it in a summer salad or as ground cover for vegetables in your garden, its presence on your lawn can be a real issue. It spreads quickly, and a single plant can produce up to 14 million seeds per year.
Needless to say, if this annual succulent plant appears uninvitedly on your lawn, you should remove purslane plants as soon as possible. Because once it goes to seed, your job can become up to a quarter million times more difficult.
So, let us teach you how to recognize purslane and the various methods for removing it.
Identifying Purslane Weed
Purslane is a broadleaf weed that grows in low-maintenance turf, turf seeded in the summer, and flower beds or gardens that have been mulched.
Each Purslane plant forms a mat between 3 and 4 feet across the ground and no more than 3 inches tall. However, mature plants have been measured to reach heights of up to 18 inches.
It can regenerate new plants from severed stems or roots that have not been removed from the soil. As a result, whenever you remove the plant from around your home, make sure to collect any pieces of the roots or stems that separated from the main plant and were left behind in the soil. Failure to do so ensures that purslane will remain on your lawn.
The leaves and stems are both fleshy and smooth. Purslane leaves are predominantly deep green in color, with red margins.
The leaves are rounded, and they grow in clusters at the stem’s joints and ends. The leaves can grow in opposite and alternate directions. They have an egg shape and grow to be between 15 and slightly more than 2 inches long. The leaves, on the other hand, can grow to be up to 2 feet long. The leaves have no petiole and attach to the stems directly.
The smooth and thick greenish bronze stems are smooth and thick. Each plant has several central stems. Their color becomes greener at the joints and ends of the stems where the leaves tend to cluster, because it has red stems that have changed color in response to the temperature drop. The stems have a sheen or luster to them as well.
Tiny yellow flowers appear singly or in small clusters on mature plants. The flowers have 5 petals and are 14 to 12 inches wide. Purslane flowers are found in the leaf axils, or at the tips of the stems among the leaf clusters.
To protect themselves from disease, the blooms will close up as the sun sets in the evening. Diseases can be caused by the condensation of water in cooler evening temperatures. When the morning sun begins to rise, the flowers will respond by opening up. It only takes about half an hour for them to fully open. If the weather is bad and the sun isn’t shining, the sensitive flowers will close until the sun shines again.
The flowers bloom primarily in June, July, and August. This window may be extended into September if growing conditions remain favorable. When the plant reaches physical maturity, the flowers will be replaced by seed pods.
Purslane seedpods are small and spherical, measuring about 15 of an inch in diameter. They have a slit around the middle of the pod that runs parallel to the ground. This allows the portion of the pod above the slit to function as a removable lid. 14 to 18 days after the flowers bloom, the seeds will mature and be ready to spread.
Purslane seeds are small and dark in color. They have been flattened and can be circular or kidney-shaped. The gleaming seeds are only about 1/50 inch across. The seeds are physically ejected from the seedpod once the lid to the seedpod is opened. Purslane ensures the survival of the species in this way.
Another feature of the seed that ensures the species’ survival is its ability to survive in the soil for up to 40 years.
The seeds germinate later than most other seeds in the spring. For germination to occur, the soil temperature must be between 70°F and 90°F. The seedlings will sprout in 10 days or less.
Purslane plants have an intricate network of fibrous roots that grow outward from the plant’s base. A thick taproot anchors the plant in the soil. Though the surface stems can grow to be up to 4 feet in diameter, the fibrous root system can grow to be more than 5 feet in diameter.
Purslane Control Methods
Purslane can be found in your yard on your manicured, green grass, alongside the borders of your garden and flower beds, and on the interior of your garden or flower beds. The control methods used in each area differ from one another.
Understanding the type of plant you’ll be fighting requires an understanding of some of its vulnerabilities.
Purslane’s Excess Moisture is a Blessing and a Curse
The leaves of the weed are filled with moisture. This is what gives them their fleshy appearance. Because of this surplus moisture, purslane has prolific drought tolerance.
This excess moisture also makes the plant averse to some growing conditions. The weed does not fare well in moist soil conditions. Full or partial shade conditions can also be disastrous for the plant. In the shade, the water does not evaporate from the already moisture-rich leaves and can cause the plant to rot and introduce disease.
Yet another drawback to the moisture within the plant is its vulnerability to cold temperatures. Some species of plants are hardy enough to survive the winter’s first frost, but not purslane. The water in those fleshy leaves turns the plant into a mat of stems with green ice cubes attached to it.
Weeds on Your Grass
Purslane typically attempts to take over lawns that have recently been sown with new grass seed or that have been neglected.
Water the Lawn Regularly
To prevent a purslane invasion, make sure the grass gets plenty of water. Water your lawn to the maximum depth recommended for your grass. Don’t give the grass so much water that it drowns, but do test the limits.
Mow the Lawn Regularly
Another strategy is to mow your lawn on a regular basis. Again, don’t overdo it, but cut your grass at the shortest recommended time between mowing sessions. This will keep it off-balance and require it to constantly replenish its nutrients in order to regenerate. Eventually, those nutrients will be insufficient, and they will perish.
Pre Emergent Herbicides
Applying a pre-emergent herbicide to your lawn is a good idea if you want to be proactive and preventive. If you can, try to keep the quarter-million seeds from germinating and sprouting.
Purslane has developed some resistance to certain herbicide chemicals. So picking one at random risks picking one that contains chemicals that are no longer effective at killing purslane.
Don’t be concerned. Because I have the information you require. Select a granular pre-emergent herbicide with 1.7 percent pendimethalin. This herbicide should be applied at a rate of 3 ounces per 100 square feet to your lawn.
Post Emergent Herbicide
If you missed the boat and were unable to apply a pre-emergent herbicide, you could be in for a battle given the potential seed count. To defeat this weed, you must use a herbicide that contains a combination of specific active ingredients in specific amounts, just as you did with the pre-emergent product.
The active ingredients and according amounts are as follows:
- 2, 4-D at 7.6%
- Mecoprop at 1.8%
- Dicamba at 0.9%
These active ingredients should be combined into a single product rather than three distinct ones. This chemical combination is most effective for treating both newly sown and established lawns.
While the weed is actively growing on your lawn, apply the post-emergent product. It is most effective if applied before soil temperatures reach 60°F. At this temperature, the herbicide has time to work before the seeds become warm enough to germinate. A soil temperature of 70°F is the absolute latest you can use it and still have a chance of catching the seeds before they germinate. However, that is quite late in the game.
Weeds on the Borders of Flower Beds and Gardens
Mulching is the most effective method of controlling purslane in these areas. A 3-inch layer of organic mulch should be enough to effectively smother any purslane seeds and prevent them from receiving the sunlight they require to begin germination and sprouting.
You have several options of organic mulch to choose from:
- Garden Compost
- Manure that has Rotted Sufficiently
- Shredded Bark
- Leaf Mold
- Essentially any organic material that you can use as mulch and matches your preferred aesthetic
Some simple instructions for you to follow to ensure your efforts are successful are included below.
- Be mindful of your ornamental plants and vegetables and avoid covering their leaves or stems with the mulch
- Fill out the layer of mulch whenever it appears thinned in certain spots
- Inspect the mulched area regularly for errant purslane plants that somehow managed to slip through to the surface (hey, it happens…)
By laying down landscape fabric before laying down organic mulch, you can double down and increase the effectiveness of your mulch exponentially.
If you’re using any of the organic mulches on the list above, you don’t need to use landscape fabric. If you choose to use gravel or pebbles as your organic mulch, the landscape fabric is a must. The space between the individual stones allows weeds to wind their way to the surface throughout the area.
Weeds Growing Within Gardens and Flower Beds
Because the soil is constantly being cultivated or otherwise disturbed, these areas are especially vulnerable to purslane invasion.
This continuous cultivation has the potential to bring weed seeds to the surface that have been dormant in the earth for the last four decades. Furthermore, the tilling and digging in these areas will inevitably break up the purslane in the ground. Those severed pieces are likely to be left there. Remember that any part of the purslane plant that remains in the ground can regenerate into a new plant.
Hand pulling weeds is one method of controlling weeds in these areas around your home. Hand pulling allows you to visually confirm that you’ve removed any weed fragments that were broken off during your efforts. However, this is a time-consuming process that is best suited for small areas of purslane invasion.
For larger areas of growth, you can use the solarization process to suffocate the weeds. To do so, you must forego the summer growing season for vegetables or ornamentals and leave the ground bare to solarize the soil.
Begin by excavating a trench around the area you want to solarize. The depth of this trench should be 4 to 6 inches. If you’re having trouble picturing what I’m talking about, think of a moat that surrounds a castle. In the same way that the moat is a connected body of water, the trench should connect at both ends.
Saturate the soil with water once the trench is finished. You must water deeply enough to wet the soil to a depth of 12 inches. Once the soil has been successfully saturated, collect your 1 to 4 millimeter thick transparent sheet of plastic. Install the edge of the plastic sheet in the trench on one side of the area to be treated, then fill the trench with soil to keep the plastic in place.
Once the plastic has been anchored with soil in one area, spread it out over the entire affected area, bury the edges in the trench, and cover them with soil as before.
Now it’s just a matter of waiting. In 4 to 6 weeks, solarization will kill any severed pieces as well as any seeds in the area. Solarization will kill the severed pieces and seeds to a depth of 12 to 18 inches.