Decomposing vegetation will leach Nitrogen from the soil. But once they break down the soil should be fine. As to whether there are insect eggs how healthy were your plants before? Not all insects are bad so that would be a call only you can make. Many here build compose piles for safety reasons away from the garden area. There are others that pile mulch all over their gardens without serious problems. Not a very good answer but all gardeners learn by the trial and error process.

The above comments are what has been learned from monoculture and the minimum plant nutrition paradigm, where a constant war must be waged against herbivorous insects.

Ignore the neighbor and read Albrecht instead.

Finally! Someone has acknowledged my expertise! Just kidding.

I have a middle of the road frame of mind. Depending on the type of debris I might leave it or remove it. Some is difficult to till, like sunflower stalks, some might harbor insect pests or disease pathogens, but you should know if you've had to treat for those. One of the paradigms of organic gardening is that healthy soil grows healthy plants which can better handle insects/disease and may even be less attractive to them, and turning in last years residue can help make healthy soil. Of course, it is your garden and you need to do what you feel comfortable with and can handle doing. I think there are many roads to vegetable success.

In a small garden like you have with 1400 SF, I'd say clean it out and compost everything. It can't take long to do and you'll be better off. I have a little larger plot and hitch up the tiller to my tractor and run through it several times and it breaks up most things so they won't be an issue later on. My main plot is 100x100 or so, and three more are about 40x60 ish each.

I figure any organic matter is good organic matter, so I leave it all. Plus I add fresh horse manure and all the leaves I can haul in every year.

No one answer works for all - as with most things in life. But in general I would agree with Chris.

In a small garden such as yours debris removal and the addition of freshly composted organic matter will serve you best. Best for disease and pest control and best for nutrients.

For those of us with large gardening spaces, tiller incorporation of that debris poses no problems. Especially so when we also use good organic practices through the season and add good amounts of actively composted materials too.

Dave

PS: I would NOT use dormant oil spray on the material if you decide to till it in. It will only bind up more N and take much longer to decompose.

Not an attack on you, trev.

Situations vary enormously by climate, soil type, and fertility, notably, when it comes to insect predation. Presuming there is no simple cause like drought, lack of sunfsall, etc. I often encounter the implication that "cleaning up" the garden will lessen or eliminate problems with insects, both on these forums and in books by supposed experts. That idea is right out of land-grant university pesticide science, IMO. It's misleading, at best, because insect attack is a result of under-nourished or otherwise stressed plants. It is not a result of high populations, or a failure to kill every insect. Also, scouring the garden damages beneficials at least as much as pests.

I am not an expert, but I do have more than 20 years gardening experience (not all of that with veggies). I agree with the clear and amend philosphy, especially since my garden is small.
Would just add that controlling insect problems organically is a multi-tiered approach. If you have a problem with Mexican Bean Beetles, Tomato Hornworms, or flea beetles pull out all that debris and send it to the dump. Do not put it in the compost pile and definitely do not leave it in the garden. If you had tomato blights, do the same. But if your plants just died a natural death, then yes, till it in or compost it. I personally like to pull it all out and compost, then add it back. I believe I have fewer problems with weed seeds and with insects too that way.
The other tier of control I would mention is the importance of crop rotation. If you had one kind of pest in one area, plant that crop somewhere else for the next two or three years.
And if something just seems to get out of hand over a period of time, plant that crop in pots or skip it altogether for a year or two and let the insects wander off somewhere else.

I try to burn the debris in my garden for two reasons. The first is that leaving it adds relatively little organic matter and the second is that burning is highly effective at controlling several diseases that overwinter on dead plants. Tomatoes are one example of a plant that should always be removed from the garden here in the SouthEast U.S.

Yes, I've tried it both ways and yes, I have a large garden. Piling and burning the debris definitely results in less disease pressure the next year.

DarJones

Honestly, you could do it either way. I would only till if the soil is not waterlogged. I always pull anything diseased and throw that in the trash and I tend to err on the side of caution, if I do not know what a spot means on a leaf, in the trash it goes.

After that, many things go into the compost. Next year, I actually plan to make a big yard for the chickens and let them find all the eggs on the plants and shred it. But, I have also left some things in place. Some of the harder freezes have finally done most of the broccoli in, but, I can occasionally still find ladybugs in them so I will let them stay. Also, snow comes and goes and our winds can be brutal so I like having the plants die in place to keep my developing soil in place. Good luck to you.

At least with burning not all value is lost.

Regarding the OP, if the idea that insects and diseases cannot be avoided without removing or burning all annual crop plants were correct, then the permaculture systems would not really function.

Let's take the MBB example: last season I established a large planting of phaseolus vulgaris in a general area (about a half-acre) where previously I had only made small plantings, never removing or burning the old plants from year to year. I don't recall ever seeing an MBB there until this large homogeneous planting, and certainly if they were present the damage was unnoticeable. This big planting was also in freshly-converted sod, sandy soil, without large additions of compost to provide plenty of the microorganisms so critical for legumes. Bang, MBB explosion once the hot weather came and the plants used up the small bank of fertility and hit some drought stress.

I understand none of us have any proof that would pass review by crop scientists, and our anecdotal experience varies. Maybe if I had carefully removed every bean plant from the year before this MBB infestation wouldn't have happened, but I certainly don't believe that. Just a very few insects can explode to huge numbers and take out any number of weakened plants by the time cold weather stops them. I will leave the dead bean plants right where they are, on the wire, and plant pisum there in the spring which will not be affected, and later tomatoes. The beans will go some distance away in soil much better inoculated with microbes.

Perhaps we should renew this thread next year and compare notes?