I would recommend contacting a local chapter of the Cal Native Plant Society for plant recommendations and they would probably know of a nearby source of bulk seed.
In most states, The State Highway Dept.also has an ongoing program of roadside wildflower plantings and could be helpful in plant selection and seeding recommendations.
In my state, the statewide organization of Federated Garden Clubs purchases and donates tens of thousands of spring flowering bulbs for roadside planting along Interstates and major multilane highways.
Good luck!
Rb

Here is a link that might be useful: CNPS-Local Chapters

If the weeds include non native grasses, just sowing seeds likely won't work, the grasses will outcompete.

To be successful, you will need to kill the weeds with either chemicals or by smothering (see lasagna gardening for details on smothering), cover the area with 3-4 inches of mulch and then plant in the plants you want. You can grow them yourself in pots from seed or buy plugs. Direct planting seeds without killing the weeds won't work.

Direct sowing seeds onto bare ground won't work either if you can't mow as weed seeds will also come in you will need to mow for one or two years to keep the weeds controlled.

Ox eye daisy is a non native weed BTW.

The fastest way I've found to kill off weeds, in preparation for native plantings, is to put down black plastic. The sun will heat up the plastic and the ground underneath, killing most weeds and cooking dormant seeds. The longer you leave it on, the better your results. (Weeks or months) When I established my native garden (not nearly as large as yours) I did black plastic for 6-8 weeks in the spring and then did lasagna layers over the killed weeds. I wintersowed a bunch of natives the next winter and planted them the next spring. I supplemented my wintersown plants with some potted plants from reputable native nurseries to give me some blooms the first year. You can also use native annuals while the perennials get established. You might even be able to wintersow natives the winter before you kill with the plastic, and pot them up so they are big enough to plant in late summer or fall rather than waiting for spring. I hope this is helpful. It does seem overwhelming and time consuming, but the results are spectacular and make you feel really good about having done something right for the environment. Good luck.
Martha

Sounds like an awful situation. It's worth your time (and $ with a lawyer involved) to determine if you can mow.

Since there are established weeds, and worse, weed seeds, the best thing is to treat the area with roundup or till right before seeding. You'll still have a lot of weeds but a lot of wildflowers too.

It's late this year to seed wildflowers if you can't irrigate though.

CJ

Generally when planting wildflowers its necessary to kill off existing vegetation, especially if its weeds. The wildflowers will have a hard time competing with already established vegetation.

If you have an easement, that says you can plant perennial and annual flowers. Does it say you can "maintain" perennial and annual flowers? Mowing would part of the preparation and maintenance for the flowers. Spraying weed killer to kill off the existing vegetation can also be considered maintenance or preparation for the flowers.

The easement language usually says that you are responsible for maintaining the access easement. Mowing can be considered part of the maitainance.

I'd like to see the language in the easement that restricts your ability to maintain the access to your property in your access easement?

I guess I didn't make myself very clear in my first post - sorry. The easement road is covered with gravel. There is a narrow 1ft strip along the edge where I could plant flowers. In the past, the road was probably narrower, thus the easement allowance for flowers. I called the attorney and he said that we could mow, but only within the easement. The problem area is part of the neighbors land that abuts our road where he lets weeds grow. I wanted to plant flowers in the little strip along our road and then "accidentally" allow some of the seed to scatter to the 20ft wide weedy area he lets grow.

Since my first post we have made some changes. The road is in need of maintenance. Thus, we are going to re-gravel but make the road narrower allowing for more room between our side and his. We are going to put up a split rail fence along our side of the property line, making the difference between our part and his clearer. Then I will plant natives along the fence line coming in and oops! if some natrualize into his weeds - oh well. :-)

I now understand that it would be best to wait till fall to sow seeds so that's the plan. In the meantime, I would love more suggestions for natives that naturalize well and are hardy & can compete with weeds. I will prepare our road side appropriately but it would be nice if they could creep over into the weeds & take over there as well. I know it will be more difficult because he refuses to mow but maybe if they get a head start in the fall when his weeds are dormant, they'll have a better chance?

Thanks again GW members! :-)

Well the fence is a great idea as it will be evident to your visitors that the land on the other side is beyond your control.

One foot is not much, is there a height restriction on the flowers? If not, plant things that get 5+ ft high and block the view beyond the fence. Here in Ontario, I would be thinking of Ironweed, Cup Plant, tall coreopsis, Sunflower, Sweet Black Eye Susan, Liatrus. Also tall grasses, like Big Blue Stem, Switch grass, Indian grass.

I'm not familiar with native California plants or the type of area you are in, the link below may be of use. Look for plants native to your part of California, and suitable for your soil/sun/moisture that get 5+ ft tall.

You would be better off to plant plants, not seeds. You can grow the plants yourself from seed, then plant them when larger.

Here is a link that might be useful: California Seeds