Once you till never put down any type weed killer. If you put in plants you can use a pre-emergent. But not in any area where you are planting seeds. You can always mulch to help keep the weeds down some.

I think Rhizo is imagining you've got more good plants with Old McDonald weeds, here-a-weed, there-a-weed... between a lot of "keepers." If it's more like that, it would be a matter of asking yourself, do I have the time to pull all of these plants up? Some people opt to remove the "good plants" to make it easier to smother large, unbroken areas. Wherever there's a gap in the smothering, weeds are, well, not suppressed, so if it's thin strips between good plants, smothering won't help much. As perspective, in my minds' eye, I see your beds as mostly devoid of desirable plants, with much space between those that would be "keepers." Although I wouldn't begrudge someone's use of chems to establish control, it would be preferable to me to smother where possible. I would define possible as any spot where I can completely cover a patch of weeds with newspaper or cardboard in large enough areas around existing plants so I could cover it with several inches of mulch without having the mulch wash "into" the existing plants. It's not that I have anything against using chems to establish control, but that's only part of the issue. If it's been lawn or neglected "flower bed," likely the soil does not have good tilth, fertility, drainage. Even this type of very basic lasagna can be incredibly helpful in all of these regards. If your dedication and determination extend as far, it's so easy to add other amendments as part of/when smothering. I like to put bagged lawnmower clippings under the paper in case it has seeds in it. (Then when the paper/cardboard contacts it, you've got a good green/brown thing composting under there.) Between the paper/cardboard and the mulch, one can add compost, leaves, whatever seed-free, easily decomposed organic matter is available. When you stick a shovel in later, that fall is OK if you want to add some shrubs/perennials, next year for summer annuals and anything more, you should be amazed by the difference. There's also an impatient form of smothering where one uses whatever they can keep in contact with the soil. A tarp or sheet of plastic, pieces of metal, the bags of mulch you will eventually use in that area, anything that will cover up the weeds until they die. After a time, you remove the cover and see if it's dead. Once you determine everything is, cover with mulch, compost, whatever your plan is, then start gardening. IME with using both methods many times, a smother layer of paper and the longer wait is worth it in the future. The quick-smother often results in the sprouting of many seeds that were at the surface but just hadn't decided to grow yet, especially right where you dig holes to add the plants that couldn't wait until next year, pretty much thwarting your efforts. With options, you can choose the best one, which you may decide is spraying. If so, putting a cardboard box upside-down on nearby plants can be helpful to avoid the mist from getting on them. Try to do when...

One of the best things I've found for weed control is a mulch covering & the best source I've found is your lawn. I have a power walk behind lawn mower with a bag attachment so I catch the grass clippings & use them (CAUTION--make sure you do NOT treat your grass with a weed killer). This also helps build the tilth of your soil. Additionally my lawn mower can be used without the bag in a mulching mode & I use that in the fall on the leaves, heavily covered areas you have to go over multiple times. After the leaves have been mulched, I put the bag back on & collect the leaves for a mulch bin to be composted & used next summer. I've found that you have to mulch the leaves first because the mower won't chop the leaves up in the bagging mode.

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