1. I believe I have some mock strawberry on my lawn (see attached) and have spent hours pulling it up by the roots. I have applied a solution of diluted vinegar
and am considering placing some cardboard over some areas. Can you suggest some non-chemical alternatives so they don’t regenerate?
2. I dug up some day lillies to split the bulbs and many of them are in clumps. I broke them into smaller clumps but do I have to separate them into single bulbs or can I replant these smaller clumps?
Thank you for contacting Toronto Master Gardeners about the control of, what you believe to be, mock strawberry (botanical name: Potentilla indica, previously known as Duchesnea indica). Potentilla indica is an invasive non-native plant originating in eastern and southern Asia. From your image and the age of the plants, it is not possible to accurately identify this plant due to its similarity to our native wild strawberry. The two main characteristics, not seen in the image, which differentiate this non-native plant from the wild strawberry, are its yellow flowers, as opposed to pink tinged white flowers, and the characteristic of the berry being held in an upright rather than drooping position. For assistance in identifying mock strawberries, click on this link – Mock Strawberry.
The literature suggests that dilute or full strength vinegar is ineffective and only temporarily damages the plant, primarily the leaves. Your preference is for non-chemical control. You are on the right track in controlling Potentilla indica by pulling it. This plant spreads through runners (stolens) which set down roots at each node forming new plants. All plant parts must be removed through hand weeding. Providing dry conditions through improved soil drainage, aeration and infrequent watering interferes with the growth of these moisture loving plants. This may or may not affect your desired perennials. Mulching with cardboard and solarization are additional effective approaches to eradicating weeds.
For further information on mock strawberry, please see:
For information on the division of daylilies, please see ‘When can I divide daylilies?’
Wishing you every success in controlling invasive weeds.