Daisies Taking Over!

(Question)

Hi gardening friends ~

Suddenly this spring, the daisies (possibly shasta, possibly oxeye) in my front garden have taken over! They’re killing my sedum and other plants. Yesterday I manually ripped out 2 leaf bags worth but of course the roots are still in the ground. From research I understand that they spread by rhizomes so I expect I need to dig up the roots. Are you able to give me any more information e.g. are they shallow or deep-rooted, will they keep recurring for years, how invasive are they? Also, can you suggest anything flowering but not invasive that I might plant to replace them? South-west facing, pretty much full sun. Black-eyed susans also turned out to be invasive as did coneflower so those are off the list. Many thanks, and stay safe!!

(Answer)

Thank you for contacting Master Gardeners.

Looks like you have a situation many people would envy, site that has good soil and full sun.  Below is a previous response to an invasive plant that was taking over a front garden.

https://www.torontomastergardeners.ca/askagardener/this-invasive-weed-has-taken-over-the-front-garden/

  • You also might try defeating the culprit by planting strong shrubs and hardy perennials that can out-compete the daisies for space and nutrients. Best would be any with large leaves such as Ostrich Fern, Hydrangea, large Hosta. Be sure to pinch out any emerging sprouts in early spring as this will weaken the creeping rhizomes.
  • If you are patient, you could try to smother the daisies by using several layers of newspaper or large flattened pieces of cardboard boxes, tape removed.   Be sure no spaces show where the pieces meet. Cover these layers with about 6 inches of mulch, not compost, and wait a couple of years.

Rather than suggesting a replacement plant, look at the website below. The Toronto Master Gardeners has a fabulous guide to perennials for full sun. This web site can give you some ideas of plants that would do well in your situation.

https://www.torontomastergardeners.ca/gardeningguides/perennials-for-full-sun-a-toronto-master-gardeners-guide/

Happy Gardening!