Creeping Thyme garden bed – grass attack


Dear MASTER Garder
I have planted red creeping thyme (Thymus coccineus) along my frt yard by taking out the grass. They are super ground cover. I put them in a year and a half back and they have taken over the whole place, exactly as I imagined. They are a key spectacle in early spring when the bloom and there are purple flowers – it’s a large carpet of purple and the neighborhood shows up to take family pictures. I have a problem now. There is a certain invasive grass that is begins to take root in one part of the creeping thyme patch ( there is a bird feeder in that area and seeds drop off and I have seen birds and squirrels pecking). It seems the grass is killing the creeping thyme in that are a nd I am afraid if it will spread. What can I do to get rid of the grass? Should I take out the bird feeder – is this the cause? Also what’s the best way to nourish and fertilize the creeping thyme to power them up for super growth? Can I put cow manure and water?


Hello, and thank you for contacting Toronto Master Gardeners with your question. It’s delightful to learn how your neighbours enjoy your creeping thyme lawn. You have three related questions. Let’s take each one at a time.


  1. What can I do to get rid of the grass that is invading the thyme lawn?

In order to implement a strategy for removal of the grass you need to identify the species. The best (and easiest) way to do this is to do it yourself with the use of any of the available plant ID apps such as PlantThis, PlantNet or iNaturalist. Once you know the plant you are dealing with, you can learn about its growth. Let’s assume this grass species has deep roots or even rhizomatic roots that network underground. In this case, its removal will involve digging deeply to remove the entire patch and every trace of root. That will result in a temporary bare spot in the lawn until you replace any lost soil, seed it with the creeping thyme and let it germinate and grow.


  1. Should I remove the bird feeder; is that the cause of the invasive grass?

While obviously beneficial to birds and entertaining for people, bird feeders often spill their contents onto the ground starting the germination process for a number of plant species. These seeds (leading to often unwanted plants) can attract animal visitors. From your description, it does sound like the bird feeder is the source of the grass, but again, it’s impossible to confirm this without knowing the species of the grass and the contents of the bird feed mixture you are using. Check the label of the bird seed product against the species of the grass. If you have a match, the mystery is solved.


  1. What’s the best way to nourish and fertilize the creeping thyme for “super growth”? Can I put cow manure and water?

Thymus ‘coccineus’ is a cultivar of Thymus serpyllum. One of the common names for this non-native, low-growing plant, is creeping thyme. In mild winters, it remains evergreen. There is no indication in the literature that Thymus ‘coccineus’ requires fertilization. The Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) (see link below) posts that “no current Ontario fertility recommendations exist.” While OMAFRA notes that “application of nitrogen after each harvest will promote re-growth” that doesn’t apply to you since your purpose is to grow a lawn and not to harvest the thyme. You describe a thyme lawn that is thriving in ideal conditions: full sun, sandy, gritty, or rocky soil, with average to dry medium moisture. Supplementing the soil with manure and water isn’t necessary. All you need to do is continue to enjoy it as you, and others, have been.