As you likely know there are many nutrients besides the N-P-K provided by the typical fertilizer. Fertilizers just don't provide everything the soil needs.

Depleted soil is easy to fix once you know which of the nutrients is depleted and a professional soil test is the only way to find out that info. They are often available from your local county extension office for a nominal fee and if they don't do them they will refer you to a source.

In many cases it is simply a matter of amending the garden bed well with a high quality compost. Many, myself included, strongly encourage a 2x a year amending routine with quality compost.

That bit of effort eliminates the need for crop rotation - which many home gardeners don't have room to do anyway.

Dave

Dave, doesn't he risk soil-borne disease, though? I thought that was a big part of rotating crops.

I rotate for heavy feeders & soil-borne disease.
But have known gardener who just laugh at a rotating of tomatoes.
If you do not have RKN & compost every season you may get away with it.
But It is easy to rotate, so I do it.

My experience this year with tomatoes reinforced the necessity for rotation. The piece of ground where I grew 30 tomato plants this summer had not had any crops on it for three years. It had lain fallow for most of that time, being cut over with a bush hog periodically. Last fall it was planted in Crimson Clover which was tilled in early this spring.

Prior to this year the tomatoes grown there had lots of fungal disease starting early in the season, mostly early blight and Septoria leaf spot. This year it was late summer before the plants were showing signs of problems and it was not nearly as bad as other years.

Just my observation this year.
Sandy

When a person has a small space for gardening I don't think it's necessary to rotate plants unless there's been a build up of spores and bacteria that fall to the ground following foliage diseases.

If there are soil borne diseases in one area of the garden I would assume that most of the time those same solborne diseases would be present throught the garden soil although there are those who have said that certain spots are worse than others.

Without rotation there are some things that a person can do.

First, in the Fall turn over the soil deeply not with a rototiller but with a shovel, That puts any foliage spores and bacteria so deep that they can't be the source of what's called splashback infection.

All new foliage diseases are acquired via wind and embedded in rain drops, so doing the shovel bit won't do a thing for NEW infections.

If nutrient depletion is felt to be a problem I know few who don't fertilize with the fertilizer of their choice, so I don't see that being a reason to rotate plants.

I used the same field for my tomatoes for 15 years and b'c it was a field with hundreds of tomato plants my farmer friend Charlie would plow deeply in the Fall, sow a cover crop of winter rye and then in the spring plow again, then prepare the fieled for me for planting.

Summary? If soilborne systemic diseaes are the problem and the gardening space is small I doubt that rotation will help. But if it's a buildup of spores and bacteria from foliage diseases then turning over the soil deeply can help. And I don't see why one would want to rotate plants for nutrient purposes when there are all sorts of ways of doing that without rotation.

Just my opinion,

Carolyn

Carolyn: thanks, I pretty much have to grow things in the same spot due to limited space. I do bury as much kitchen waste (eggshells, coffee grounds, peelings, etc.)as I can... but have now gotten good sized potatoes that grow from the plants from the buried peelings!! I now make sure I bury the peelings in just one area so I don't have potato plants coming up in my tomatoes, carrots, beans, etc.!! Our caliche soil now is so much better & with added volcanic sand from the west side of the city, it has really improved so much. If many, many earthworms now plentiful in the garden soil are any indication of better soil... then it is!

I have been growing tomatoes in the same gardens for decades. The most 'rotation' they get is maybe moved over a row or two and traded off with bush beans or potatoes. No disease problems.

What prevents the problems is an very active soil amending routine. Twice a year - early spring and late fall - the gardens get several inches of high quality, homemade compost tilled in. During the season addition compost is also used to top dress and side dress the plants.

Quality compost will control many soil pathogens with beneficial bacteria and deep tilling as Carolyn mentioned is also quite beneficial.

It is important to keep in mind that the most common tomato disease spores are not just soil borne, they also airborne. So you can rotate all you want and still get the diseases.

Instead I prefer to focus on keeping the soil as healthy as possible. Healthy plants thrive in healthy soil and are much more disease resistant.

JMO

Dave

To Dig Dirt,
Dave,
It might help many of us if you could expand upon your definition of "high quality compost". There is so much poor quality material offered out there today....even from once reputable brands. What goes into a home made, high quality compost? Thank you for your continuing and helpful advice to gardeners young and old.
Victor

Victor - It is more a discussion for the Composting Forum - a great forum full of info and a detailed set of FAQs. I linked the Info FAQ below as a good place to start.

The very best compost will contain a wide diversity of organic ingredients not just 1 or 2 things - leaves, straw, mowed grasses or hay free of herbicides, shredded paper and cardboard, chopped food scraps, chopped garden cleanings, and various animal manures (see list linked below).

It will have been actively managed, kept hot and cooking by maintaining a balance between the greens and brown ingredients, turned/stirred often, kept properly moist, etc. rather than just dumped in a pile and left to sit and depend on the weather. It will be well-aged and at least 90 days old before application, smell clean like soil with no ammonia odor, the particles will be small, basically unidentifiable, and dark brown in color, and they will hand-squeeze into a clump that then breaks apart easily.

Personally, IMO home made compost is far superior to any commercial product if for no other reason then you control what goes into it and how the process is managed. But I also recognize that many simply don't have the room I have to do composting so must rely on commercial products.

And there are public composting sources available that will work for the average home gardener with a bit of attention and care. Properly run city/county composting operations are worth investigating before buying bags of anything. But you need to ask questions before using it. What goes into their piles, how is it managed (active turning and mixing vs. passive piles), how old is it, how does it smell and feel, etc.

Bagged commercial compost is a last choice IMO but it can be used IF it lists the ingredients, if it dry and light-weight, and if it smells and looks good - open a bag and check it before buying - and IF you understand that it won't be as good a quality and will require you add other things to it.

Bagged composted manures are ok if you mix it well with another carbon first like shredded leaves or chopped straw. Bagged non-manured compost will need additions of greens such as grass clippings or granular fertilizers of some kind such as alfalfa meal or cottonseed meal to work well. And if forced to rely on commercial bagged compost then use as much of it as you can afford and expect it to take a good year of using it before result will be noticeable.

In addition to the Composting forum check out this article Mike wrote in Organic Gardening years back.

Hope this helps.

Dave

Here is a link that might be useful: Composting forum FAQ - Intro

SOME tomato diseases are wind- or rain-borne, but others are primarily caused by splash-up from the soil during rain. I wouldn't dismiss concerns about primarily soil-borne diseases because some other diseases are also spread by rain. Lower branches are often attacked first for a reason, and many growers cut off lower leaf-bearing branches for that reason.

If you can't rotate, then you just have to deal with what you've got. But just adding compost to soil won't make soil-borne diseases go away. Mulch will help stop splash-up and help prevent problems. Turning over the entire garden will as well, but it can be a lot of work.

Jon, in my post on Sept 23rd I spoke to all NEW infections being transmitted by wind and rain, but didn't mention splashback infection specifically.

And the bacteria and fungi that do fall to the soil from infected plants due to foliage diseases are not really IDed as being soilborne systemic diseases b'c those are in the soil all the time as opposed to bacteria and fungi that fall to the soil and don't stay there very long, perhaps a few years at most.

Some diseases that would be considered as systemic soilborne diseases would include Fusarium, Verticillium, Southern Blight, and the like.

Hope that helps,

Carolyn

But just adding compost to soil won't make soil-borne diseases go away.

I am not saying that compost cures all but let's not totally disregard the many university studies that show that beneficial parasitic bacteria and other microscopic creatures in compost can neutralize and even kill many of the pathogenic bacteria in soil. They can also control the reproduction of several varieties of fungi by altering the pH of the soil and out-compete them for the available nutrients. Plus control some viruses by neutralizing their needed soil hosts such as pathogenic nematodes.

As Carolyn indicated above the soil borne diseases include Fusarium, Verticillium, Southern Blight all of which are far less common than Alternaria, B. Speck and Spot, Early Blight and Septoria which are airborne.

Dave

I've been growing in the same bed for the last 6 years. Every year after the growing season is over and I clean up the bed I add horse manure and compost. 3 years ago I went no-till and just added the manure and compost and let it sit. Buy the time spring rolls around most of it has broken down by the time I get ready for plant out.
When I plant out my seedlings I dip the roots in a dip consisting of Actinovate, Biota Max and MycoGrow soluable which are selected fungi and bacteria that help control soil borne disease and also assist the roots in getting nutrients for the plants. All I can say is every year my plants are getting taller and fruit production increases.
Ami