I have an “L” shaped garden facing west and north. It is bordered by two fences- a black chain link fence on our property and a wooden fence on the neighbour’s. In between the two fences are perennial weeds that I cannot reach to dig out. This includes creeping bell flower, garlic mustard and dandelions. I have been using a vinegar based horticultural leaf spray which has been somewhat successful but very time consuming. Do you have any suggestions of how to get rid of invasive weeds in hard to reach areas? My garden is well mulched but the weeds still creep in.
Thank you for your “awkward” question for Toronto Master Gardeners. You have a real dilemma and a serious problem with the weeds.
I suppose the first solution, to work out a compromise with your neighbour so as to eliminate one fence, has been considered. This would be ideal, as the land is useful to no one and is actually causing problems. If you cannot talk to the neighbour, perhaps you could source out a local negotiator with the city.
In the meantime, we are mandated to promote natural methods of plant removal, even in the case of invasive weeds. Below is an answer to a similar question which we posted on our website, in the Ask A Master Gardener section, where you’ll find many more helpful ideas: www.torontomastergardeners.ca/askagardener/identifying-and-controlling-invasive-weeds/
Garlic mustard is considered one of the most problematic and common invasive species in Ontario forests. It is a biennial, forming rosettes in the first year and tall flowering stalks in the second. The seeds, which form from flowers on the second year plants, can remain dormant in the ground for five or more years.
You can take the following steps to remove this plant from your garden, and to prevent in spreading throughout your neighbourhood:
Hand pulling – this control method can be appropriate where there is a relatively small population of garlic mustard. However, it must be done thoroughly, including getting out the root, as the plant can continue to sprout new stems from the root and the accompanying soil disturbance will stimulate germination of garlic mustard seeds in the soil. Hand pulling is more likely to be successful if followed by replanting of native species as some species can successfully out compete garlic mustard.
Basal cutting – which involves cutting the stem at the base on the second year plants, ideally just after the plants flower and before they produce seeds. As garlic mustard plants flower at different times, you may need to repeat this several times. This control technique will reduce soil disturbance and may reduce seed germination. Cutting is preferable to hand pulling because it reduces the soil disturbance. Depending on the area where the plants are growing, you may be able to do the basal cutting with a mower.
Use of herbicides – in a home garden, under Ontario pesticide rules, you are not able use herbicides to control garlic mustard (there are exceptions for agricultural lands and forest management).
Note: do not compost any plant material. It should be put in yard waste bags and ideally left in the sun for at least a week before being disposed of. This is important because pulled plants which have flowers can still produce seeds.
The Ontario’s Invading Species Awareness Program web site has some excellent information on garlic mustard and other invasive species. https://www.invadingspecies.com/invaders/plants-terrestrial/garlic-mustard/
Once the area is rid of the invasive plants, as the answer suggests, it would be a good idea to plant native trees and shrubs so the weeds cannot get hold again.