Don't be confused by all those letters and numbers! The N-P-K letters stand for Nitrogen-Phosphorus-Potassium. (The “K” is the chemical initial for potassium.) On each fertilizer label, you will see the percentage of each of these primary nutrients in that fertilizer product. For example, a 10-20-20 fertilizer contains 10% nitrogen, 20% phosphorus, and 20% potassium.

These nutrients, called macronutrients, certainly aren't the only ones plants need, but plants use them in the greatest quantities. You'll sometimes hear the term "fertilizer ratios." This is simply the ratio of each to the other. Divide the numbers by the lowest number in the group of 3 and you will have the ratio. For instance, 10-20-20 would have a 1-2-2 ratio, and 15-15-15 would be 1-1-1.

Nitrogen is the nutrient most often in short supply in soils. It stimulates vegetative growth such as leaves and stems, and gives a lush green color to leaves. Phosphorus stimulates root growth, hastens flowering, and promotes increased disease-resistance, whereas potassium increases the size and quality of fruit and flowers, among other benefits.

The balance of these nutrients can be as important as how much you apply. For instance, a tomato may respond with lots of vegetative growth and few fruits if you give it too much nitrogen. If you give it too much phosphorus and potassium, and no nitrogen, the result can be a small plant that produces only a few tomatoes.

Other necessary secondary nutrients include magnesium (Mg), calcium (Ca) and sulfur (S). Magnesium is the core chemical of chlorophyll in green leaves. Calcium is needed for strong cell wall formation and root growth. Sulfur acts together with nitrogen in plant cells.

And, not to confuse you, micronutrients are necessary as well. These are trace elements, present in very tiny amounts. Examples are zinc (Zn), manganese (Mn) and iron (Fe). Iron is also necessary for chlorophyll production.

If a plant has yellowing leaves, or chlorosis, the pattern of that yellowing is important for you to note.
• Yellow leaves that are smaller than normal – needs nitrogen
• Yellowing between the green veins – needs iron
• Veins lighter in color than the tissue between them – needs sulfur

Be sure to use a fertilizer that is specialized for the type of plant you are feeding and the right time of year for the application. If you are not sure, just ask one of us and we'll help you sort it out!

One other quick note: Butterflies also like puddles. Provide a small water source in your garden with a shallow birdbath or buried bucket filled with stones and then filled with water.

By the way, did you know that the Natural History Museum of Los Angeles has a Butterfly Pavilion?

For more information, go to: http://www.nhm.org/exhibitions/butterflies/

Across the country, bees have been disappearing at an alarming rate. Entire hives set out on what was presumably their normal day work of collecting nectar and pollen, but they never returned to their hive. This phenomenon is termed Colony Collapse Disorder, not an unknown event. But this year, commercial beekeepers are alarmed because it is happening to an extraordinary number of hives.

What does this matter, you ask? Aren't honeybees just garden pests that fly around, seek out humans and sting, sting, sting? Well, not really. In fact, if a bee would sting you, that would be the end of its life. And keep in mind, honeybees only choose to sting when they are protecting themselves or their hive. Otherwise, they really have no interest in us whatsoever.

In reality, honeybees are absolutely necessary in our environment; they are nature's pollinators. They pollinate our flowers, and not just the pretty ornamental flowers in our gardens. So, although our beloved literary bear character Winnie the Pooh believes, "The only reason for being a bee that I know of is making honey...and the only reason for making honey is so I can eat it" (A.A. Milne), he's not altogether correct. Sorry, Pooh.

Honeybees are hard-working pollinators of the world's vegetable and fruit crops. You might think of them in this way...when their work is done on farms across the country, then they have time to seek out our flowering trees, shrubs and perennials in our gardens.

Commercial farmers have worn the hat of not only a farmer but also of a beekeeper for years. And there are commercial beekeepers maintaining hives and supplying them to farmers at the appropriate pollination times of the growing season. That is how very important this fantastic creature is to our economy and environment.

Read more about the hive losses at the following websites:

American Beekeeping Federation: Honey Bee Die-Off Alarms Beekeepers, Crop Growers, Researchers

LA Times: Flight of the honeybees