I have a client w/a large yard, a visible corner lot, who wants to eradicate the Scilla that is blooming now and appears to be spreading. We have tried to dig it up, and noticed that some of the plants have a large bulb, and some have several smaller bulbs under one flower. It seems like a nearly impossible task, without tearing up the yard completely. Any ideas? Any experience with this?
Hennepin County Minnesota invasive species
I assume the Scilla is Siberian Squill as it is the most common; it has the blue flowers. I also have a lot of it and it is spreading, but in some areas where I don't really care. Scilla seeds profusely.
Getting rid of it is not easy. There are reports that even glyphosate (Round Up) is not all that effective. As you have found digging is not that effective as it (apparently) can re-sprout from any missed bulbs or roots. I am afraid that the ultimate solution is going to involve "tearing up the yard."
Here are a couple of suggestions:
1. Mow or cut the plants down before or during flowering to reduce seed production and the spread.
2. Strip the plants of any seed pods.
3. Dig the bulbs as best you can, and continue to stay on top of any regrowth.
4. Cover the main infestation with black plastic for at least one summer and maybe two. Obviously this will kill the turf as well and you will have to reestablish the turf. 5. Turn the main infestation into a island flower bed. Dig out the Scilla as best you can (or cover the area with black plastic) and then control any spread on the perhiphery by mowing, striping seed pods, etc. Stray Scilla that comes up in the garden can be dug.
6. You can try using glyphosate and just keep after the survivors. But again you will have to reestablish the turf.
Hope this gives you some ideas. Scilla is very difficult to eradicate.