How Many Fertilizers Do You Need?

Southern Living, Apr 2004 by Bender, Steve

Not as many as you might think.

You have to hand it to marketers because those folks sure are clever.

Why, they can sell you something, put it in a new box, and sell it to you again five minutes later. Don't believe me? Stroll down the fertilizer aisle at just about any garden or home center. You'll see box after box of fertilizer "specially formulated" for just about any plant you have: azalea food, bulb food, chrysanthemum food, pansy food, tomato food, shrub food, African violet food, houseplant food, rose food, and flower food. (What? No rhubarb food?) Yet, when you check the percentages of nitrogen, phosphorus, and potassium they contain (as indicated by the three big numbers on the label), the difference is often insignificant. I mean, there's not much difference between a plant fed with 9-9-6 versus 7-11-9 or 11-10-13.

Give Them What They Want

To be fair, one reason retailers carry so many different fertilizers is that customers ask for them. People think a product specially formulated to grow tomatoes or mums or kiwi vines must do the job better than a general-purpose one. This isn't necessarily true. So how many different fertilizers does the average homeowner need?

Well, here's what I think. Certain plants have special nutrient requirements and therefore need special fertilizers. So if you're growing palms, citrus, or pecans, feed them with products formulated just for them. And believe it or not, buying a special pansy fertilizer is worth it if you're growing pansies, violas, and other cool-weather flowers. Why? Most fertilizers contain nitrogen (the most essential nutrient) in the form of ammonium or urea. Plants must convert either one to nitrate before absorbing the nitrogen. This conversion slows drastically in cold weather. Pansy food, however, supplies nitrogen as nitrate, so plants can use it immediately from fall through spring.

Growing azaleas, rhododendrons, camellias, gardenias, and other acid-loving plants? Chances are, you'll need an acid-forming fertilizer containing the mi- cronutrients iron and sulfur, Miracle-Gro Water Soluble Azalea, Camellia, Rhododendron Plant Food 30-10-10 and Holly-Tone 4-6-4 will work. Good old cottonseed meal is okay, too, if your plants look fine and don't need supplementary iron or sulfur.

One Type Fits All

Most plants that you grow-whether roses, vegetables, shrubs, trees, houseplants, or flowers-will do fine with a general-purpose fertilizer. That is what "general-purpose" and "all-purpose" mean. But there are two .. different kinds. One is a quick-release powder you mix with water (the blue stuff) that feeds immediately and then is quickly used up. Peters Professional all Purpose Plant Food 20-20-20 and Miracle-Gro Water Soluble all Purpose Plant Food 15-3 O-15 are the most popular. You need one of these because they're easy to use and give quick results.

The other kind is a slow-release fertilizer that comes in granular form and feeds for many weeks. Good examples are Osmocote Vegetable & Bedding Slow Release Plant Food 14-14-14 and Ultra Vigoro Ail-Purpose Plant Food 12-5-7. You sprinkle them around the base of the plant or scratch them into the soil once or twice in a season.

Those are all the garden fertilizers you probably need unless you're growing poison ivy. In that case, I'd highly recommend that you try Green Scream 36-1-1.

STEVE BENDER