Are Epsom salts good for outdoor garden plants (trees, perennials, evergreens, deciduous etc)? If so, how much & when do I use the Epsom salts? Please let me know which plants would benefit from this solution.
The best information I found on the use of Epsom salts in the garden comes from horticulture professor Linda Chalker-Scott of Washington State University. Epsom salts are also known as magnesium sulfate, and the theory (or the myth, according to Chalker-Scott) is that adding this substance to the soil provides necessary nutrients to plants, and improves their growth. The reality is more complicated, and she ultimately recommends that home gardeners not use Epsom salts, as they tend only to be useful in intensive crop production (such as farming) where there is a known lack of magnesium.
Rather than use Epsom salts, you might simply make a practice of amending your garden soil regularly with compost. WSU lists some of the many benefits of using compost.
Seattle Public Utilities also has information on growing healthy soil and composting.
We plan to put in a vegetable garden next spring where we now have grass. It is a great sunny spot that we think would work well for this. The question is, after we cut out the sod this fall, someone has suggested we plant rye grass for the winter, is this a good solution? If not, what do we do to the soil this winter? (We plan to bring in some top soil after we take out the sod).
There are several approaches that you can use to get your new garden ready. One is from Growing Vegetables West of the Cascades by Steve Solomon. He
recommends removing the grass, covering it with no more than 1/2 inch of
completely rotted compost or 1 inch of raw ruminant manure, and spread
agricultural lime at 50 pounds per 1,000 square foot. Do this in early
October. Then scatter small-seeded fava bean seed at 6 to 8 pounds per
1,000 square feet. Rototill no more than 2 inches deep and relax until May.
In late May you rototill deeply and or spade in the overwintered garden
area. Then you can plant.
Another information source, Seattle Tilth’s Maritime Northwest Garden Guide,
recommends using an annual winter cover crop to improve the soil. It
suggests using 85% legume and 15% grain for maximum nitrogen fixation. For
the legume, you can use Field peas, Crimson clover, Fava beans or vetch. For
the grain you can use cereal rye, winter wheat, spelt or barley. Most of
these are applied at about 2 pounds per 1,000 square feet. Again you would
rototill or turn under the cover crop in late April or May.
Solomon’s method will provide a better total approach. You also should
consider having your soil tested to find out what is missing and what your
pH level is.