Is it all right to use my husband's pine shavings from his router on my tomato and pepper plants? Thought I had better ask the experts. Thanks!

Wood is great to mix into soil. But when you have very fine grinding (like from a router' even finer than saw dust) it could get mudy, so mix it into your soil or compost. and it will be fabulous. Just take 10 seconds to fluff the dirt and saw dust. You dont want a solid cover that will cap your compost pile and encorage only anearobid bacteria

carolyn, you can use the shavings as mulch but never ever ever mix it into the soil. Router shavings are much more course than any sawdust but either way never mix it into the soil as it will rob the soil of nitrogen if mixed in. Fine shavings that are in potting soils have been composted and never mixed in raw. Only use wood as a top mulch only.

Keith, that's simply not true. (Edit.. keep reading, I later found out Keith isn't entirely off the mark... research references follow in my next posts).
You may be thinking of grass clippings that are wet and flat and so nitrogen dense, they can compress enough to create an impenetrable cover and anaerobic environment high in methane ... which adds nitrogen to the soil, but takes away needed oxygen. The problem in that case is excess nitrogen, But I can't imagine where you got the idea ground up trees steal nitrogen.

Wood shavings, especially coarse ones, are excellent additions to soil. And you must mix them so they do not create an impenetrable layer where fungus and bacteria that feed on the wood can create a concentrated mat.

Exterior grade woods treated with chemicals to stop rot might be an exception, but who is putting decorative edges on exterior lumber with their router?

I did some research, and Kieth is correct that bacteria that degrade wood use nitrogen from the soil, but only studies that used a very high (1/3 ratio) of wood to soil had a measurable decrease in available nitrogen, while both drainage and moisture retention, biota, mineral content and growth rates over 3 years were markedly improved with addition of wood chips even at that level.

https://journals.ashs.org/hort...

The addition of almond wood chips lowered soil pH, increased soil carbon, and organic matter contents and enhanced water infiltration in soil planted with almond trees in the San Joaquin Valley, CA (Holtz et al., 2004). However, the application rate was unrealistically high (≈410,000 kg·ha−1 or one-third of soil weight) and resulted in initial immobilization of soil INORGANIC (emphasis added) nitrogen. In a previous report (Tahboub et al., 2007), we found no significant effect of wood chip incorporation on plant-available nitrogen, phosphorus, or potassium at application rates up to 17,936 kg·ha−1 and concluded that wood chip incorporation was a viable means of wood disposal.

Wood chip incorporation should increase the organic matter content of soils and improve soil chemical and physical properties. The continuous use of hardwood chips for a period of 15 years at an application rate of 7000 kg·ha−1·yr−1 in the northeast United States increased organic matter content, aggregate stability, and moisture retention and reduced soil bulk density, pH, and soil erosion (Free, 1971). Sanborn et al. (2004), while studying the effect of wood chip incorporation on the rehabilitation of older landings and roads constructed on fine-textured soils in British Columbia, Canada, found that soil bulk density at 7 to 14 cm was lowest in the wood chip-amended soil when compared with the topsoil amendments. The wood chip treatment had also the highest 3-year growth rates of hybrid white spruce. Based on these promising results, the authors recommended silviculturists to use chipped wood wastes in the rehabilitation of disturbed lands.

Although our previous report showed that nutrient immobilization was not a concern with pecan wood chip incorporation, the potential beneficial aspects of wood chip incorporation on soil organic matter and the effects on soil chemical and physical properties were not included.

Net net is that incorporating mulch may reduce the amount of non organic available nitrogen in the short term, But it increases soil quality in terms of mineral content, drainage, moisture retention (if you've seen "well draining moist soil" and thought it was an oxymoron.. this is how you do it.) biota diversity and resulting growth rates at up to 1:3 ratio.

The beds I mulch every year, and in the spring I turn the mulch back into the soil, have a fabulous outcome. Thank you for pointing out the nitrogen tie-up and sending me on this research quest that shows the truth of what you know, but that appears to have been overstated. Churning in wood debris has a positive overall outcome on growth, soil retention, crop quality despite initial drops in free organic nitrogen soil tests that equalize over time.

For someone just starting, it's helpful to know some additional nitrogen might be helpful if your wood to soil ratio is higher than 1:3. Let your dog pee there once a month on a rainy day and you can reap all the other benefits of incorporating wood into your soil.

Turbosaurus said:
The beds I mulch every year, and in the spring I turn the mulch back into the soil, have a fabulous outcome.

The important part of this statement is that you give the mulch a full growing season (or longer) to begin the process of decomposing [on top of the ground], before tilling under.

I have dumped old sawdust on beds and turned it under without the time spent as a mulch... and... it seemed impossible to add enough nutrients to get anything to grow for a number of years.

Sawdust dumped on top of the beds and left to decompose until it starts growing weeds... works fine.

stone said:

The important part of this statement is that you give the mulch a full growing season (or longer) to begin the process of decomposing...

I have dumped old sawdust on beds and turned it under without the time spent as a mulch... and... it seemed impossible to add enough nutrients to get anything to grow .

What YOU missed was
Saw dust vs Mulch
Published peer reviewed data

Apologies to all who took the time to research my question. I thank everyone sincerely. The sawdust was placed around the tomatoes, green beans, Brussels sprouts, zucchini, and cucumbers. I did give them several drinks of Miracle Grow, which they appreciated greatly.

In the south sawdust is used to grow strawberries...but it always depends on the type of wood- some are alleopathic and can 'poison' while they decompose. Areas matter, weather matters, the fine dust stuff- like paper used in old phone books gather moisture, then if run over/compressed enough turn back into a really brittle wood- shouldn't be an issue how you used it. If you watch your plant it will tell you what it thinks about where it is growing and what you fed it