I know, I know, that is a very open ended question and depends on a lot of factors. The reason I bring this up is because I thought of purchasing some Miracle Grow all-purpose plant food (20-20-20), for my landscaping plants, but then I questioned if I even needed it. So far, my landscaping plants include Froebelli Spireas, Gold Mound Spireas, Summer Wine Ninebarks, a Diablo Ninebark, Rosy Glow Barberries, lavender Chrysanthemums, hostas, oakleaf hydrangeas, Walkers Low Catmint, Russian Sage, Autumn Joy and Autumn Charm Sedums, Sonset Lantanas, Wine and Roses Weigelas, Pampas Grass, and a Chinese Pistache tree.
I use natural wood mulch and pinestraw mulch with no plastic weed barrier for all of my mulching needs. And everything except the tree is mulched with one or the other. My soil is sandy loam and acidic to neutral in its ph range. I didn’t use any fertilizer last year and everything seemed to grow and bloom fine. The only questionable area was with the Froebelli and Gold Mound spireas. Some of the leaves on both of these plants turned a very pale yellow, almost white, color but didn’t wilt or die. They seemed very healthy except for the color. Those plants are in morning sun and afternoon shade. I don’t know if a fertilizer would have corrected that or not.
Anyway, do you think my plants could benefit from the Miracle Grow plant food or would I just be wasting my money? Please let me know what you think.

Thanks,
Tim Elliott

Answer #1 · Maple Tree's Answer · Hi Tim-It sounds as though most of your plants are doing well. Its hard to tell what was happening to the spireas. This could be the result of mineral definciencies or possibly too much water. I believe most of these plants are fairly young or newly planted from what I remember of your gardens. Sometimes we have a tendency to over water new plants making sure of their survival the first year. Too much water can cause this lighter coloring of the leaves without wilting or other signs of problems. These plants in the hot summer temperatures can also turn a lighter yellowish green. Keep an eye on them this year and let us know how they do this coming summer.
I'm not one to fertilize much during the year when plants are doing well. I do fertilize once each year in the spring with a fertilizer for all my shrubs and trees. A few acid loving plants I fertilize separately with fertilizers formulated for azaleas and camellias but over all I use an organic fertilizer for the whole garden. I only use the All Purpose water soluable fertilizers on some house plants and potted plants when needing a quick fix for some nutrient deficiencies. Some of these quick acting water soluable fertilizers will feed for a small period of time but need to be mixed accurately in order not to burn or over fertilize plants. They also do not last very long in the soil as watering will leach them through the soil quickly. A sandy loam is nice for most plants and is most likely well draining allowing liquid fertilizers to move down through them more quickly. Most liquid fertilizer instructions state their applications should be made every 14 days or so making some very expensive. I always use a slow release fertilizer that I can use once in the spring and feeds the plants and trees for several months during their growing season. I believe organic fertilizers are our best choice because of their micronutrient content and the ability to fertilize and act as a soil conditioner. As Brent has noted in answering questions, many gardeners spend their time and money feeding their plants with synthetic fertilizers, which are designed and work to feed and boost only the plant. Organic fertilizers are designed to feed the plant and the soil. Soils rich in nutrients sustain plants naturally requiring very little supplimental applications of fertilizers in time.
I noted below a link to a previous question I answered regarding the use of all purpose water soluable fertilizers you may be interested in reading. The links below will give you some fertilizers I feel have worked well for me and a few reviews of some organic products you may be interested in. I also noted a link to a good article on How To Fertilize Shrubs and Trees. Just click on the links to go directly to the articles.

http://www.gardenality.com/Questions/2112/Plants/Perennial-Plants/What-Are-Some-Better-Fertilizers-Than-Miracle-Gro.html

http://www.gardenality.com/Articles/92/How-To-Info/Fertilizing/How-To-Fertilize-Shrubs-And-Trees/How-To-Fertilize-Shrubs-And-Trees.html

http://www.gardenality.com/Articles/859/Reviews/Product-Reviews/Milorganite-Fertilizer/default.html

http://www.gardenality.com/Articles/1118/How-To-Info/Fertilizing/Review-of-Nitroganic-Fertilizer/default.html

Hopefully this has helped. Please ask if you have any other questions.

John)

Answer #2 · Gardenality.com's Answer · Hi Tim - If your plants are doing fine without fertilizer then I'd say you don't have to fertilize them. Some plants do fine feeding just off decomposed organic matter, compost or readily available nutrients that exist in the soil. When the foliage of a plant starts to look a little dingy or its growth rate has slowed considerably, and I've determined it's not from insects, disease or soil pH, I feed them with an organic plant food. I never use synthetic fertilizers, and especially don't like any of the Scotts products, such as Miracle Gro. Instead, I use one called Nitroganic, but this product isn't available oustide the Southeast US. Milorganite is a comparable fertilizer and there are scads of others on the market. Reason I like these two products is that they contain 4% naturally occurring iron and also help to repel deer, of which there are many around my property. They also contain lots of natural nutrients and elements not listed on the bag and are totally non-burning, which means they're "goof proof"....and won't burn your plants. Here's a link to a page about Nitroganic and/or Milorganite...

http://www.gardenality.com/Articles/1118/How-To-Info/Fertilizing/Review-of-Nitroganic-Fertilizer/default.html

Regarding the spirea, the bleached foliage could be due to a lack of sunlight, or possibly poor soil drainage and soggy soil? Typically, spirea prefer full to mostly sun. I have probably 5 varieties growing in my landscape including Gold Mound, Reeves, Pleno, Anthony Waterer and Little Princess and the ones in full sun are doing fine. A few Gold Mound are under some crape myrtle trees in the front and in the shade their leaves are a bleached out, light lime green color rather than golden-yellow.

Brent)