I have an out of control clover infestation in my flower bed, but every time I dig out a batch of clover, it just springs back up within a month. The native grasses also seems to love the flowerbed.
It's my understanding that the broad leaf herbicides that kill clover will also kill the flowers.
Does anyone have tips or suggestions on how to keep a neat flowerbed?
Composting
Herbicides (Postemergent)
Herbicides (Preemergent )
Mulch:
Solarization
What solarization is?
From Wikipedia: Soil solarization is an environmentally friendly method of using solar power for controlling pests such as soilborne plant pathogens including fungi, bacteria, nematodes, and insect and mite pests along with weed seed and seedlings in the soil by mulching the soil and covering it with tarp, usually with a transparent polyethylene cover, to trap solar energy. It may also describe methods of decontaminating soil using sunlight or solar power. This energy causes physical, chemical, and biological changes in the soil.
Solarization may kill clovers?
Yes, it will kill clovers, but seeds may remain intact (especially large seeds). Remeber that clovers seed can survive for years in dry soils.
Solarization may have many side effects on the bulbs?
Not sure, bulbs may be destroyed by heat or may be rotten for the high soil humidity...
My experience with solarization
I made two solarizations time ago. One of them to kill a very invasive species of Ipomoea and the other to remove a fungus in the soil. Both were very effective.
When I made the solarization against fungi, I noticed a decrease in the number of clovers and weeds in general (maybe 60% or 70% less).
The likelihood is your clover and grasses are rooted in with the plants you want to keep. Couch grass is difficult to eradicate by any means, clover you can get rid of - but it requires effort. You need to dig out as much of the roots as possible, preferably when the soil is nice and moist, loosening the soil around the clover then extracting it carefully with its roots. After that, frequent hoeing and removing the hoed off parts will deal with it, but, at the right time of year (autumn) I usually clear the bed if the colonization of weeds is extensive - I dig up everything that can be dug up, all the ornamental plants as well so long as they're not large, established shrubs. Then I inspect the rootballs of the ones I want to keep, extracting anything that shouldn't be there (couch grass roots, clover roots and anything else I don't want), thoroughly dig over the area removing any roots, then replant the newly cleaned ornamental ones you want.
If possible, it would be good to know what part of the world you're in and to see a couple of photos of the problem, showing the clover in particular. If you're in the USA, the area you're talking about might the size of a field for all I know, which would render the solution I've suggested so far irrelevant.
UPDATE: I've just noticed one of your responses in a comment above says that all the flowers are daffodils. Well, no problem then, if you're in the northern hemisphere - dig 'em all out now and thoroughly dig the bed over, removing all roots. You will need to have those daffs back in place by end of this month though. You might also want to consider planting properly in the bed, that is, plants which at least give ground cover during the time the daffodils are dormant - if you don't plant something in bare soil, nature will, as you've discovered.
I would suggest using mulch. The trick is to use a very thick layer - about 6 inches. This should take care of clover. Grass will get trough the first year. But mulch will not allow for the grass to reseed itself, so once you weed the current one, new one will not settle in.
Might as well add my own method, to add onto the other valuable input you've gotten so far.
If all you have in the beds are daffodils, here's what I'd do:
Dig all the grass and clover you can. If you have heavy or wet soil, don't chop it up. Go through and try to dig out the main crowns first. After the bed is cleared of the biggest stuff, go through again, and pull up along any rooted stems by hand, and quickly dig out the roots as you go.
The bed should now appear free of grass and clover, but there are generally still some roots. Wait one week. If any leaves come through, dig out the roots supporting them. You can repeat this step if you want.
Put down a layer of mulch. Dyed wood chips or premium bark mulch are good for appearance. Don't add more than 2". Make sure there are no piles, and the surface is even.
There will likely be some roots you missed. They will use lots of energy emerging, and will be weakened. Use a probe, or digging knife, and walk through now and then popping up any clover you see. I reckon this should take less than 15 minutes every couple weeks, per 1000 sq. feet.
As an alternative to the last step, When you see weeds emerging, walk through and spray them with Roundup (glyphosate). This will kill the roots. Clover may take more than one application. After the roots are dead, all you might find will be seedlings, which may be removed by the root easily enough.
Add a covering of new mulch each year.
If you want, you can apply a pre-emergent herbicide before you lay the mulch. This will greatly decrease the seedling count that you'll get.
You could also start by spraying the entire bed with Roundup, but I always recommend using the least possible amount of pesticides. In the case that you do this, wait 1 week, if there is any green lefty spray again. Wait two days, cut to surface level, and mulch.
