Three invasive species questions
1. Every spring, my yard is covered with what I think is celandine (shiny heart shaped leaves, yellow flowers). The area is covers spreads every spring and then dies off after a couple of months A few years ago, I tried spraying it with an herbicide. It didn't work and just killed the adjacent plants. Any suggestions? it's just started to appear and I'd like to get a head start on it this year. 2. Last summer Japanese stilt grass appeared in large areas of my lawn. What can I do to get rid of that? 3. I have several beds of English ivy. Last year, one of them died off over the winter and has not regenerated. What should I do to get it growing again
Howard County Maryland
We apologize for taking so long to answer you question. Normally questions are answered the next day, but the University has been closed for spring break.
1. Lesser celandine is not too hard to kill. Here is an excellent site for lesser celandine (also known as fig buttercup) control: http://www.nps.gov/plants/alien/fact/rafi1.htm You'll notice that a systemic, such as glyphosate, works well, but should be applied before flowering and may well require application twice in consecutive years. Also, be careful if spraying near water of any kind. Glyphosate formulas can be deadly to aquatics, incluidng frogs and other amphibians. Near water, special formulas must be sprayed, such as Rodeo or Erasure, that are safe around water.
2. Stiltgrass is very difficult to control. Never let it go to seed (late summer) in beds, etc. If you only have a small amount in your lawn, you might ever consider pulling that. Most homeowners use a crabgrass preemergent application in spring around the time that the forsythia blooms are fading/falling. This also kills emerging stiltgrass. However, it does not last all summer and a second application may be required. We have a fact sheet on preemergents in our Publication section, under lawns: TT 43 (link is external) - Herbicides for Crabgrass and Goosegrass Control in Turf
3. If your ivy bed has been dead since last winter, there is no possible way to rejuvenate it. We cannot recommend growing English Ivy because this is one of the worst non-native invasive plants in Maryland, gobbling up woods and wild areas more and more. We'd recommend you plant something else there. There are many excellent and beautiful possibilities, including natives such as ferns, green & gold, foam flower, creeping phlox, Canadian ginger and Alleghany pachysandra (not Japanese pachysandra!)