Question
Hi Mack,

I've read that using baking soda can make soil more alkaline but since it's a salt, would it strip the soil of nutrients?  Also, I've started growing a potted Oklahoma rose for the first time and used some coffee grounds since I've read it can make soil more acidic as well as give a little nitrogen boost.  The rose is growing beautifully but is it possible to add too much coffee grounds?  I just mix the grounds into the topsoil (I don't compost) if that makes any difference.

Answer
Dear Shawn,

I've never heard of adding baking soda as a soil additive, but I accept your conclusion that it could strip the soil of nutrients since it is highly alkaline.  I am very familiar with and use baking soda and water mixed as a foliar spray to prevent mildew on my roses.

Are you familiar with adding Epsom salts to your roses?  Rose growers, in particular, are strong advocates for using Epsom salts. They claim it not only makes the foliage greener and more lush, it produces more canes and more roses. To apply to existing rose bushes, either mix ?cup of Epsom salts into the soil around the rose bush and water well or dissolve ?cup of the salts in water and use to water the rose bush. Do this in the spring, just as the bids are beginning to open.

Regarding using coffee grounds for your roses:  go to this website:

http://www.homeandgardenideas.com/gardening/flowers/roses/how-fertilize-roses-co

They provide the following recommendation:

"Using coffee grounds for either or both compost and fertilizer can truly have a lasting effect on your rosebushes. Some gardeners suggest that it boosts your plants natural defense mechanisms, making it easier for them to ward off pests and disease. Coffee grounds contain about 2 percent nitrogen, another third of a percent of phosphoric aid, some level of potash, and varying levels of other nutrients. They are considered a great fertilizer for plants that normally have an acidic diet, such as roses, providing minerals, carbohydrates, sugars, and vitamins to its roots.

However, when you are applying coffee grounds, don't apply them in a thick layer or have them too wet. Coffee grounds tend to get mold if left in this state. If you mix with ground up eggshells and dried coffee grounds, this could help to stimulate the plant, especially ones that may need lime added to their soil. They receive the lime from the egg shells and are then provided an extra boost through the coffee."

By the way, I love the "Oklahoma" rose; it is truly a magnificent thing of beauty

Sincerely,

Mack Jean
AllExperts
Master Gardener
Tennessee