What I do is this. I finely cut up the leaves in the fall and scatter them on the garden and them lightly till them in then [in the fall]. By mid April it would be hard to find them. You see, by getting them into the soil in the fall and having them there already in the spring, nature has already composted them.

The leaves have likely already decomposed quite a bit. My recommendation would be to add the leaves as a mulch after preparing your soil. Sprinkle a bit of cottonseed meal (or similar) first if you are concerned about nitrogen. Then you can turn them in at the end of the season as suggested by wayne_5 although, personally I would leave them as winter cover if possible...the earthworms will appreciate the food and the protection. Either way the soil will still benefit as the leaves break down. Link is for comparison of nitrogen sources.

Here is a link that might be useful: SOURCES OF NITROGEN FOR ORGANIC FARMS

Got a coffee house nearby? Many will save UCGs (used coffee grounds) for you. The wormies love them! They do have some nitrogen. Nancy

I am strongly in favor of adding unfinished compost to the garden. The earthworms and the fungi need food, and if you want them there working for you you have to pay them. The same holds for kitchen scraps in a parallel thread. Finished compost can be sterile for some important members of the food web, specially hot compost.

Every fall, and often in the spring too, I would pick up those bags of leaves people would set out by the curb for pickup, take them home, and often shred them to make compost or use for mulch or sometimes leave them whole and use them for mulch. Shredding those leaves allows the bacteria to digest them faster, although they will digest them even if they are left whole eventually just as they do in the forest.
Whole leaves spread on the garden as mulch do as much good, eventually, as shredded leaves put on the garden as mulch, but those whole leaves can suppress some plant growth just as whole leaves cause problems with some early spring flowers by restricting access to the sunlight plants need to grow.
Tilling those leaves in to the soil could cause a temporary loss of Nitrogen as the Soil Food Web uses that N to work at digesting those leaves just aas they do with any material that has a high Carbon to Nitrogen ratio, leaves range from 40 to 80 C:N ratio.
Double digging might be necessary once, but has no real benefit if done once the soil problems have been corrected.

Here is a link that might be useful: About Double Digging

Could I wait until I mow the grass and add the grass to the garden soil with the leaves? Would that make up for or cancel out the nitrogen needed to break down the leaves, or is that better done in the end of the season to give time a chance to do it's job?

Most people will recommend doing that in the fall rather than spring, so the materials have some time to decompose. BUT the concept of lasagne gardening uses fresh uncomposted materials in layers too. It all depends on the amount - how thick would the layer of grass/leaves be if laid on the surface? An inch or two may not be noticed by your plants if tilled in now. 6" might.

I usually mix grass clippings with last fall's leaves and use that as mulch during the hot summer. As soon as the tomatoes are planted, they get mulched to keep the blight from splashing up during rains. By late summer, the mulch - which is actually a good compost mix (as you already know) - will have decomposed away, feeding the plants in the process.

Most people seem to have gotten the idea that compost can only be made in the fall seems to have developed because that is when large volumes of material (leaves) is available. There is no good reason why compost piles cannot be started any time of the year and since it is really better to put compost on the garden in the fall beginning to make compost then is a bit late.
With good planning, and doing as much of your prep work in the fall, you can eliminate that great spring rush to get the garden ready.

There are leaves and leaves, too. My leaves are mostly oak and most of them show signs of decay, but then digging them in will not give you a nice soil surface to seed, for example, carrots (I will use what is left in the orchard). Well matted, dry maple leaves are strong enough that garlic will not be able to push through. Locust leaves are tiny and can be added anytime.

It is usually a good idea not to amend the beds where you will be directly seeding small seeds, carrot, kale, arugula, lettuce, celery, parsley, that kind of stuff. You can amend at will where beans, potatoes, squash, and transplants will be used. If in doubt, a little shot of nitrogen will speed decay and last through the season as the leaves release it later on. Do not forget to use all leftover leaves in mid-June, to mulch large plants such as tomatoes, and get some summer composting in.

Am so glad I found this Forum and this post. Every Fall my Dad tilled leaves into his garden then in the Spring he would plant. Because he only had one leg we would put ground leaves down between the rows. He had a bountiful, weed free garden.

I blow leaves out of the flower beds, cut them up with a mulching mower several times and blow them back. The problem is we run out leaves and I don't want to pick up the neighbors ...afraid of what else I might pick up,

I took all of mine and the neighbor's leaves last Fall, shredded themm and piled them on the berry rows for winter and following Summer mulch. No doubt the soil critters will be dining on them throughout the warm months coming up. The excess went into the compost bins last Fall and is waiting for greens to blend with and compost.

Love that chipper/shredder or the leaves in the berry beds would be a sloppy wet impenetrable mat right now!

michael, I agree with cutting leaves up finely. Whole leaves can blow away badly and tend to leave a sodden mess underneath.

I mow mine up in the fall, mixing the leaves with grass clippings, then use that to mulch the vegetable garden beds. It insulates the soil so it won't freeze, and slowly decomposes over the winter - in the spring, I just plant right though whats left of it. The worms do the tilling for me.

For the last few years, I've been putting a thick layer of finely chopped leaves on my raised vegetable beds in the fall. Every year at about this time I think that I put too many on, and they will be in my way when I plant in another month or so, but I have found that they break down a lot between now and planting time. There isn't much left and I can turn it in without any problem. I don't seed many plants with tiny seeds, though. Usually I am putting out starts.