It’s common for a gardener to come in and
ask for fertilizer for a specific plant. We get a request for plumeria, African
violet, citrus, or any of a hundred other different kinds of plants’ specific food.
Well, gardeners, it’s time for an intervention. Plants do not know what the name is on
the label of the fertilizer. They honestly could not care less. They’re only concerned with getting the
nutrients they need to grow and thrive. The reason you see so many different
products listed for specific plants is the same reason you can go to the store
and find many different brands of aspirin. It’s called marketing. Plants need
specific nutrients – some in large quantities, some in very small quantities.
When purchasing a fertilizer, by law, three numbers must appear on the bag. They are “N”, “P”
and “K.” Or nitrogen, phosphorus and potassium. I know you would think it would
be “NPP” but the chemical symbol for potassium is K which makes it confusing.
It’s also why chemistry people aren’t invited to many parties. In the most
general of terms each chemical has a certain function. Nitrogen is important
for producing new cells such as leaves and stems. Now if I had a plant that I
want a lot of leaves, like lettuce or kale, or my oak tree, I would feed it with the
fertilizer where nitrogen, the first number, was larger than the other
numbers. Phosphorus is necessary for the
production of flowers and fruits. So to make my rose bloom or to produce large
tomatoes, I would make sure there was more phosphorus available. Potassium is like a blood-pressure
medicine. It makes it easy for plants to move food and water from leaves to
roots and back again. That makes potassium an important nutrient during
drought or cold conditions. Now to make matters worse, the quality of your soil
can make it easier or harder for the plants to get that food – even if there’s a
lot of it available. That is why it is so important and possibly most important to
focus on maintaining a soil full of organic matter and rich in biology. This makes it so much easier for the
plant to take up the nutrients it needs. It means it needs fewer nutrients. When you purchase a bag of
fertilizer that is labeled for one particular plant, it doesn’t know if your
plant is in Texas or New York, how much sun it’s getting or what the temperatures
are, or the last time it rained or if you had to use dynamite to dig the hole to
plant it in. And what about one fertilizer that has real small numbers and one has
really really large numbers? Does it make it better? Nope. A plant will only use what it needs. There is a limit as to how much
fertilizer can actually take up. Too much of a nutrient can even be toxic to the
plant. Just because there is more nutrient doesn’t mean the plant will use
it. It means it goes to waste. Just like your money. You feed when the
plant needs food not because someone put a schedule on that particular plant on
the bag. It’s easier to find fertilizer formula for a specific plant. Don’t let
it distract you. The right nutrients for the plant
should be based on what the plant needs at the time, not what’s on the label.
Where the plant is growing, what its environment is like, what you are looking
to encourage it to do, are the most important factors to take into account.
The focus should be the big picture, not just a small part of it. For backyard
basics, my name is Jeff Ferris.