Go ahead and plant and see what happens. I figured the heavy clay at my home would not be good for asparagus, but I planted anyway. That was 20 years ago and the planting continues to yield well. Sometimes spears are crooked or weird looking, and I assume it is because they had trouble getting through the heavy soil. But most are okay and all taste good. I did not amend much and have often wondered if doing so would have allowed water to sink in more quickly instead of running off the slight slope of the bed. Perhaps amending would have given me a permeable bed that fillled with water and would not drain from the clay bottom...but I don't know. So I'm not sure if I should encourage you to amend.....or not. But I think there is a good chance you can grow asparagus without making major changes to the soil. If you do want to amend alot perhaps you could go with raised beds.

I hope the three households are going to help out with the chores :-) You have a good plan going there and I really hope it goes well for you. I think you are going to have to go vertical on some of those crops (like the cucumbers, tomatoes, maybe melons, pole beans) otherwise simply walking through the garden will pose a real problem. I agree with glib that you are going to need a bona fide soil test done. Check with your local extension office or do a quick google search. They will be able to provide more accurate assessment of the nutrients there (for instance, nitrogen is notoriously difficult to accurately measure and I would be suspect of any testing that includes nitrogen without special handling procedures). Are you planning on growing on this patch for years to come, or do you only need short term space. If it is long term, you are going to have some tough decisions to make. First, do you adopt an organic approach. I would argue that any soil needing to grow for more than three years should be organically managed. Salt build-up, destruction of organic matter and permanent damage to the soil food web are just a few results of using chemical fertilizers (i.e. Miracle Grow, or anything water soluable and more than 3-3-3, or anything greater than 5-5-5 or so. Even if it says organic, you can't necessarily believe it). If you are using the plot long term, you are going to have to focus on soil fertility. In vegetable growing, the mantra really is fertility, fertility, fertility. How to max fertility? Organic matter at 4-10%, balanced levels of major and minor nutrients, good tilth and drainage with sufficient moisture retention to prevent leaching. Crop rotations to avoid buil-up of soil diseases and nematodes. Diverse habitats to attract beneficial insects and pollinators. Wow, sounds really easy when I type it out. I am on my third year in this location and I am still working out fertility issues. Some parts are better than others for certain crops. For instance, you mention heavy clay. Well clay is not that bad as long as it isn't in a low lying area. Actually, if you are growing any brassicas (broccoli, cabbage, cauliflower, kale) they very much prefer clay soils because of fertility retention. So, where does this leave you? Read, read and read some more. For now, get a delivery of compost, probably two or three yards. Make sure you are getting it from a reputable source: most urban compost delivery comes from sod farms and they are notoriously toxic. Find a local source for organic fertilizers: soybean meal, alfalfa meal, dolomitic lime, kelp meal (if you can afford it), bone meal, dehydrated chicken manure. These are just a few suggestions. Do a google search for Solomon Complete Organic Fertilizer for a great recipe. Spread out a layer of about 2" of compost on top of all your bed sites. Broadcast a half of a gallon of COF into each bed. Then till or hoe in the compost to a depth of around six inches. Water it in. Then spread another 2-3" of compost on top to create a raised bed, borrowing some from the pathways if necessary. Broadcast another half gallon of COF onto each bed. Rake it in, creating a nice, smooth seedbed in the process (rake the clods and rocks into the pathways). Bingo, you are ready to go. As for year two and beyond, well, that is another post I'm affraid :-) Best of luck, and let us know how it turns out! Michael

Re Making Hard clay soil workable . One good cover crop is tiller radish (diakon) You plant in fall at least 60 - 90 days before a hard frost . The roots will grow down up to 2 feet and die with the frost , they reduce compaction, and provide organic matter and quickly rot . You need to add nitrogen to promote their rapid growth. Another thing you can do is add powdered gypsum ,wet down and till in fine pinebark. There is also a liquid gypsum you can apply with a hose end sprayer . When you till clay soil it is necessary to have the right amount of water to keep from damaging soil structure. Any kind or free organic matter helps you can use powered charcoal , used coffee or tea grounds , any type of manure , mulch , sawdust compost , leaf much , after tilling or amending soil add about 4 inches of mulch such as tree chipper mulch, grass clippings or leaves. Within 1 year soil should be workable . As far as rocks, they will surface every time you till , just set them aside and after a while the amount of rocks will decrease . As far as tilling hard clay wait for after a hard rain and bust soil with railroad pick or garden tiller and it will be slow going the first time . If you take a handful of soil and make it into a ball ,and throw onto a hard surface it should crack a little but not turn to dust . Do not try to till when too wet or too dry . Another trick is to get a 2 foot long drill bit in hammer drill and drill holes in fall and fill with water , when water in holes freeze it will help to soften soil . Some crops such as carrots and beets are better grown in raised beds until soil becomes more workable .

I planted a cover crop for my clay soil a few years ago but planted as calistoga suggests, in the fall to catch the rains. I planted an annual mix (not perennial!) of oat/cowpea/bean/vetch that I got at the local farm supply. When the plants had about half bloomed (and before setting seed -- important if you don't want them coming back next season), I cut it all and let it lay on the soil and eventually tilled it in. I don't know if I would till if I did it again as it does disturb the soil structure (not to mention those lovely earthworms). But my method worked for me -- it added a lot of organic matter to my soil inexpensively and without backbreaking labor. The only cost was time, which I could more easily afford.