It depends on your site and what your ultimate goal is for the area. Eliminating existing competition from whatever is growing there now will most often give you the best results if you want to promote a dense planting of native wildflowers and grasses. Think about this way. Whatever is growing there now has already proven its ability to outcompeted native vegetation. That's why those species are flourishing there instead of native plants. If on the other hand, you have a significant amount of native species, then it might be reasonable to work with what you have. It is also possible that you may be satisfied with not going totally native and to just have a meadow look with the option of introducing additional species to add color and interest; albeit, hoping that those introduced species can coexist with the existing vegetation. The advantage of going the later route is that it will be a lot less work. You have to check with local weed laws to see if any of the above options are viable.

Are you talking about planting seeds? If so, there's little to no chance of success if you don't kill the existing vegetation. Newly emerged seedlings usually can't compete very well. Even when existing vegetation has been killed before seeding, weed competition can still be a problem.

I don't know if this will help. I live in a traditional suburb, but I have gradually added beds and every year I widen them and add new ones as the old ones mature and become more self sufficient. This way I never have an overwhelming amount of weeding to do, but my beds are all natives and become more lovely and swarming with birds and insects every year. Maybe you could clear one section and plant it and leave the rest to manage in a less intense way and see what works for you. I find that nature is not in a hurry, so I shouldn't be either. There is always next year. Most importantly, don't bite off more than you can manage. I've heard too many stories on these forums of people starting out with grand plans and being over whelmed with the project/weeds and having to start all over--or giving up all together. Every little bit helps, so no project is too small. This should be a project you can enjoy, not a burden. Just my two cents worth.

Martha

Excellent advice and a good reminder, Martha, for all of us, no matter the size of our gardens. Plus, if the project is done a section at a time, it will allow time to determine what plants will grow well and thrive in that particular meadow setting.

~Mary

Martha, That's a great way to expand. I really like it. I think that's the approach I'll take on the front lawn area. Gradually eliminate lawn, expand native gardens, and introduce small meadow plantings. I think another benefit of your approach is that the neighborhood folks won't have a huge shock to their image of the well maintained yard. The only problem is - I'm impatient. So I'll do the "radical" changes in the back, out of street sight areas. Thanks for the inspiration.

(I'm chronicling my journey of mind and landscape in a blog where you can follow along.)

Take care,
Hal

Here is a link that might be useful: Hal's Native plant landscaping journey