How to get rid of bluebells without digging, glyphosate, or covering them with plastic bags

Question

I have an infestation of bluebells, (or at least, some type of weed that produces pretty blue flowers that grow from bulbs), in my lawn. Last year I dug a whole bunch of them out, but they've returned with a vengeance this spring.

I don't want to dig all of them out again, for a couple of reasons:

1. I'm worried that they multiplied last year because I didn't dig them out properly or something. Could this have happened, or are the plants that have come up this year just bulbs that didn't grow last year?

2. I don't want to have even more pockmarks all over my lawn.

Also, I can't use glyphosate because they're on my lawn and I don't want to kill the grass. Finally, there are too many to cover each one individually with black plastic bags, and even if I did, the lawn would look really bad.

So my main question (in addition to (1) above): if I periodically snip the leaves as short as I can, to stop them from photosynthesizing, will the bulbs eventually run out of stored energy? How many years will this take? Would it be better to wait until they flower every year and then cut them?

I don't have pictures of the flowers but here are the leaves after mowing the lawn.

Answer 1

I'm going to go out on a limb and suggest that your blue flowers are Scilla sibirica. These are naturalized in many parts of the northern midwestern and eastern US States and, I believe, in southern and eastern Canada. If I'm correct, then the plants go dormant about four weeks after blooming, leaving your lawn weed-free on its own.

The bulbs you're seeing in areas where you removed the bulbs are probably seedlings from previous years (they can take 3 years or so to bloom from seed), so you'll be continuing to see new plants for several years yet.

Personally, I love the little guys as harbingers of spring and a carpet of bright blue in late April/early May, but do see your point as one corner of my lawn seems to be nothing but scilla leaves from mid-April to mid-May. I like the look, however, and just mow them down when they start to yellow.

You, though, don't like the look, so to control them the easiest thing to do is simply to mow them. Mow them as short as possible (although too short will be bad for your lawn) because you're right - lack of leaf coverage will mean less to poor growth for the bulbs and you may (I stress, MAY) weaken them enough where they die. OTOH, even if you don't kill them, they won't be able to bloom (so no seeds and no future plants) and you won't notice the leaves.

So - just mow them down when you mow your lawn; even if it doesn't weaken the bulbs, know that they'll go away on their own in six weeks or so. This advice applies to ANY bulb in a lawn.

Answer 2

Start with testing the soil.

The grass stand looks poor, and probably is poor due to unfavorable conditions for grass. Aeration and providing nutrients the soil lacks, and/or adjusting pH if needed, can make a big difference in turf health. If an area is heavily shaded, it may never do well for grass, unless the shade is reduced.

If you improve conditions to favor grass, grass will be more likely to win. If you don't have a "pure grass lawn" fixation, small clovers can help as well, but that's not an option if you have the "pure grass lawn" fixation.

Merely eliminating the weeds won't, of itself, make the lawn healthy.

Answer 3

I would treat them like other weeds. Spray them regularly with Glyphosate. I know you said, you didn't want to use it. But it has a bad rep from a study where they fed the equivalent of something a bucket a day (for a person) to a mouse. I still regard it as the safest herbicide out there.

You can get wands that you just dab, instead of spraying like this

Yates Zero Weeding Brush

This is from a reasonably recent study (not a literature review)

We recommend further work to evaluate exposure across populations and geographic regions, apportion the exposure sources (e.g., occupational, household use, food residues), and understand temporal trends.

The evidence of human exposure to glyphosate: a review