The pros and cons of using mushroom compost

It’s garden questions and answers again! You may e-mail me
questions at [email protected]. Or you can mail me questions in
care of this newspaper. For a faster, personal response, please
include a self-addressed, stamped envelope.
It’s garden questions and answers again! You may e-mail me questions at [email protected]. Or you can mail me questions in care of this newspaper. For a faster, personal response, please include a self-addressed, stamped envelope.

Q. I look forward to your column and enjoy all the helpful information. There is one thing I’d like more information on. I’d like to know the pros and cons on using mushroom compost in our flower and vegetable gardens. There is an abundance of it in Morgan Hill – some of it for free and some for a nominal fee. A deal too good to be true? – M.N., Morgan Hill.

Great question because mushroom compost can be obtained in our local area for free or almost free. I’ve used mushroom compost myself in the past with great results. Mushroom compost can supply nutrients and increase water-holding capacity of the soil. But mushroom compost can also be too much of a good thing for seeds, seedlings and young plants. The soluble salts and other nutrients in fresh, undiluted mushroom compost can be too concentrated for germinating seeds, young plants and other salt-sensitive plants, including members of the heath family, such as rhododendrons, blueberries and azaleas.

In other words, using too much mushroom compost in your garden can possibly “burn” plants. The safest way to use mushroom compost this time of year is to use it sparingly. To be perfectly safe, mix mushroom compost with garden soil before using it on young plants. Or, you can also let your mushroom compost sit uncovered to “cure” over a few months.

Again, I’ve used mushroom compost before with positive results. However, I also spread my mushroom compost around in the middle of winter when there was little chance of it being too “hot” for my garden.

These same precautionary measures should be taken with similar organics, including horse manure, steer manure, chicken manure and others. One of the biggest problems pertaining to natural manures are weed seeds. Whatever that animal ate, it’s going to show up in its manure. The packaged manures we buy have all been sterilized so thousands of weed seeds won’t sprout up throughout your garden after you’ve spread it around.

Q. I read somewhere that planting geraniums will keep flies away. Any truth to this? – J.W., Gilroy.

We must have read the same article about someone who got this advice from a friend in Germany. He tried planting a few geraniums in containers on his front porch and it seemed to work. We all know that geraniums have a definite odor and I guess it could be offensive to flies. Truthfully, I have geraniums growing on my back patio, but I haven’t noticed any fewer flies.