You don't want to use herbicides but you are looking for something to kill weeds.

The solution to dandelions is to grow tall, dense, turf. Here's how you get there...

2. Water deeply and infrequently. Deeply means at least an hour in every zone, all at once. Infrequently means monthly during the cool months and no more than weekly during the hottest part of summer. If your grass looks dry before the month/week is up, water longer next time. Deep watering grows deep, drought resistant roots. Infrequent watering allows the top layer of soil to dry completely which kills off many shallow rooted weeds.

3. Mulch mow at the highest setting on your mower. Most grasses are the most dense when mowed tall. Bermuda, centipede, and bent grasses are the most dense when mowed at the lowest setting on your mower. Dense grass shades out weeds and uses less water when tall. Dense grass feeds the deep roots you're developing in 1 above.

4. Fertilize regularly. I fertilize 4 times per year using organic fertilizer. Which fertilizer you use is much less important than numbers 1 and 2 above.
   

If you do this you will not have weeds to kill. I'm thinking you could raise your mower height to the highest setting and the dandelions will be gone in a month or so.

Did you know there was a lawn forum where you could ask this question?

I'll toss in my 2 cents on this one. I agree that a healthy, long turf keeps weed growth down. However, established dandelions are going to be hard to drown out now. I find that it's easiest to kill all the weeds first, and then maintain a longer, healthy lawn. Part of having a deep root system for your lawn is having good topsoil that goes fairly deep. As many of us know, most yards don't have much for topsoil, usually somewhere in the range of 6". Under that is your junky subsoil, where your grass roots won't go. For example, I have an area in my yard that was filled with all topsoil, and goes at least 18" deep. I have NO weeds in that area, because the grass is thick, and the roots strong and deep. In other areas, where the topsoil is 6 to 8" deep, the grass is nowhere near as healthy, due to a lack of deep roots. Weeds can easily find a small bare spot and fill it in.

So, with all that said, I think you have to make a choice here. The first one is to take the easy, cheaper route, and get the weed & feed. The other choice is to go all out, and start mowing high, fertilize 4 times a year, and water appropriately. With 2 acres, you will rack up a nice sized water bill, not to mention you will either need a sprinkler system for thousands of dollars, or you are going to need to go shopping and buy lots of hoses and portable sprinklers. Then, you will need to be out ALL the time, dragging hoses and moving sprinkler.

When I first bought my house, I was gung ho with my lawn, keeping is golf course quality. After a few years, I grew tired of the time and effort it took, and also with the rising cost of fertilizer products. Basically, every time I needed to fertilize, it would be around $100. That is $400 a year, plus the water bills when mother nature didn't help me out. I decided I was wasting my time and money, so I now just mow a bit higher, and occasionally drop some weed & feed down. All & all, if I were you, I'd get the weed & feed.

Joe

Take a good, in depth, look at your soil. While dandelions, and other "weeds" will grow in about any soil conditions they can indicate soil related problems, becasue they do have preferences. This link might provide some insight.

Here is a link that might be useful: Weeds and soil

Joe has some good points which I missed. 2 acres is a lot to water. An area that big will need a permanent, in-ground, watering system if you want it to look nice. If you are not willing to do that, then you should look into using native grasses instead of turf grasses.

An alternative is to put something else in for all but about 2,000 square feet of that. Here are some suggestions that I compiled back in 2006...

Decks, patios, privacy fences, accent fences, screens, formal and informal walkways, steps, spa/hot tub, barbecue/picnic area, retaining walls, arbors, overhead sunshades, screened rooms, gazebos, sun room, greenhouse, swimming pools, garden pools/ponds, tool shed, potting bench, dog run/kennel, accent lighting, storage units, statuary, benches, sports courts, jogging track, hedges, decorative gates, drives/parking areas, parcours, remote party room (for games, TV, pool table, etc.), shade trees, outdoor theater, fruit orchard, accent trees, play yard, screen shrubs, accent shrubs, vines, ground covers, ornamental grasses, and beds (perennials, annuals, bulbs, herbs, ferns, roses, hostas, container plants, rock, and fruits).

You can look at them differently, their tap roots help break up the soil, and they draw nutrients up from further below and bring them to the surface. I have 2 acres of lawn as well, and I got tired of constantly spraying, fertilizing, mowing, watering, etc. So 4 seasons ago, I over-seeded the existing KBG mix with white Dutch clover seed to fix nitrogen, and aside from saving hundreds of dollars on chemicals and fertilizers, I use less water, mow a bit less, I now have a far healthier, fuller, and greener lawn, I have abundant, safe grass clippings for mulching.

So I think of dandelions as my little nutrient mining friends. "You go, little buddies" I tell them.

Yeah, until your 3 year old daughter comes to see what you're up to in the veggie garden with a nice, full, fluffy dandelion seedhead, makes a wish, then blows all of the seeds right onto the fresh, open soil.

Joe

Ah, yes, the seed head tradition. It starts with simple, diapered crawling and blowing them everywhere, then toddling around and blowing them, then bringing bouquets indoors and observing the physics of seed head/ceiling fans. Later, they move onto soccer kicking techniques and golf clubs.

All part of the rich tapestry of gardening that is our heritage.

2 acres is way too big to maintain as lawn. Are you playing football or golf on it, are you grazing animals? If not, I would significantly reduce the lawn area, to about 1/4 acre around the house. The remaining 1-3/4 acres should be converted to a native grasses/prairie/meadow which requires much less maintenance, less mowing, less water, no fertilizers, etc. etc.

Here is a link that might be useful: south carolina native plant society

You could try letting part of your yard go to a wildflower pasture. Will take a little work to get started, but once established will be maintenance free and beutiful, not to mention great for attracting pollinators. I think you could also mow it very late in the fall to collect for compost. I think most of the wildflowers will have already dropped seed.

Make a note though, that wildflower pastures require burning every few years to prevent takeover of one species, and to kill off invasives. Sure, you don't HAVE to do it, but if you don't, you have a good chance of having problems with invasive grasses and weeds taking over, slowly but surely. Burning the pasture will kill some invasives, and set others back so much that the native flowers can crowd them out.

Joe

Usually an annual mow can take the place of a burn, in areas where burning is not a good option.

Burning is fun! and is great for controlling unwanted weeds in a natural area.

I'll put in a good word for trees...

do some searches on here for using vinegar as a herbicide. basically you put it on the leafs and it will kill them. of course they will probably come back up latter.

The idea that you would be catching the clippings on 2 acres of lawn seems very silly to me. The wealth of the soil under that lawn is being robbed every time you take away those clippings, and that wealth is needed for the health of the lawn. I even think folks that rake up then haul off leaves from their trees are just ripping off their own yards. I think if I were you, I might take part of the lawn and grow something in particular that you want to use as mulch, buckwheat, clover, etc. You can grow it thick so it shades out weeds like dandelions. You'll be far better off with the lawn by leaving the grass clippings on the lawn. And look around for other possible sources of mulch in your community. There are so many people that just throw out stuff you could use. And if you ask, sometimes they will save it for you, bring it to you, call you when it is ready, etc. Also consider the amount of gasoline you are using to keep that two acres mowed - no amount of mulch is worth that...

I have been mowing the yard for many years, and using the clippings. It was my parents house, I live next door. Dad died a year ago this month. Dad always insisted that I cut it short, even though I knew better, his happiness was more important. So I will renovate it this fall.

I bought out my brothers share of the home and farm. I have planted some trees since Dad died, but they will take a while. The home sits 150 yards from the road and that is the reason for such a large yard. Wildflowers sound nice, but I don't think they would look correct inside of a circular asphalt driveway. I think they would look more like weeds.

It does sound like maybe other sources of garden mulch would be a good idea. I don't know if you'd be interested in wood chips, but the utility crews will often deliver chipped treetops by the cubic yard. In summer they have a lot of leaves and twigs in them, so they will provide some N although not as much as grass clippings. Around here they do not even chip trees that are already dead, to avoid spreading any diseases, so the chips are top quality.