By Stephanie Rose
Let’s continue the examination of soils we began last time, shifting our focus this time to fertilizers and the ways they can be used to tailor soil to the specific needs of the plants you and/or your clients have chosen.
Fertilizing is important, because placing a plant in the ground and providing it with ample sunlight and adequate water in the proper location is only part of the battle. True, plants may thrive under those ambient conditions, but treat them to even minimal amounts of fertilizer and those same plants will show their gratitude with a beautiful display of foliage, blooms, fruit and other wonderful things.
Fertilizers provide nutrients for plants that the soil and water alone cannot supply, and they come in hundreds of variations designed to offer the correct nutrients for just about any type of plant. Knowing the basics will help you choose the right ones for your clients’ gardens.
Before you begin, however, it’s important to recognize that soils do tend to provide some nutrients, which means you need to determine which type of soil you have and what nutrients it will naturally provide. As discussed last month, this can be determined through simple texture tests (wet the soil, let dry for one day, pick up a handful and squeeze some in your hand) and/or with commercial soils tests. Once you have determined soil texture and type, its time to move on to choosing the best fertilizer for your site.
THE LOWDOWN ON FERTILIZERS
With so many to choose from, it can be daunting to enter the fertilizer section at a good-sized nursery or garden center. How do you know which one to select?
The first thing you need to know is that every bag or can is labeled with three digits known in the trade as N-P-K numbers. N is nitrogen, P is phosphorus and K is potassium, and these are the macronutrients contained within the fertilizers.
They are always listed in that N-P-K order, and the number itself represents the percentage of the given macronutrient contained within the fertilizer. A product labeled as 10-20-6, for example, will contain 10% nitrogen, 20% phosphorus and 6% potassium.
Nitrogen works primarily to aid leaf and overall plant growth, while phosphorus mainly promotes flowering and fruit growth. For its part, potassium mostly helps build the strength of plants through strong stems and root systems. That’s oversimplifying things quite a bit, but these are the main functions of the three components.
You can purchase either a complete fertilizer that contains all three nutrients, or you can buy one with only the macronutrient your plants specifically need. Many gardens, for instance, lack sufficient quantities of nitrogen, which means picking up a fertilizer labeled as 10-0-0 might be just the ticket. (This product type is known as a simple fertilizer because it contains only one of the three macronutrients.)
Once you know what nutrients a given set of plants needs, there’s another decision to be made – this one about the type of fertilizer you’ll use. Many gardeners are simply concerned with getting enough of the right food to their plants and don’t much care about whether the products they pull off the shelf are all-natural, but it matters to some and must be considered.
There are two primary choices here, either for chemical or natural fertilizers. Chemical fertilizers generally contain higher levels of the nutrients, are typically faster acting and cost less. The disadvantage of these fertilizers is that if they are applied too heavily, they can burn root systems and permanently injure plants.
For those who prefer a more natural solution, there are organic fertilizers. These derive from such sources as animal manures, animal blood, bones, fish and other sources, including worms. These fertilizers release nutrients as they decompose naturally into the soil and tend to be more benign than their chemical cousins.
No matter whether you and your clients opt for chemical or natural approaches, fertilizers generally come in liquid or solid form.
I know many people who swear by liquid forms, but my preference has always been for solid fertilizers because I find them easier to apply. They also tend to release their nutrients into the soil more gradually, allowing the plants to be fed over a longer period of time. By contrast, liquid fertilizers tend to leach out of the soil fairly quickly with regular watering – their main advantage being that they work very well when you need an extremely quick fix with a single plant.
There are also “time-release” fertilizers, such as spikes. I haven’t had tremendous luck with these and still prefer a regular program designed to put fresh nutrients in the soil at regular intervals. Basically, these are matters of personal preference – and of the amount of personal attention you or your clients want to pay to their gardens to keep the plants thriving.
My own approach is the result of having toiled in this industry for 14 years – a time during which I’ve witnessed my share of plant suicides as well as plant murders I committed at the behest of clients who wanted to have the most spectacular garden in the neighborhood.
After much heartbreak (and expense), I grabbed the bull by the horns and devoted myself to learning what I needed to know about fertilizers and proper approaches to fertilizing. The foundation of my education was provided by an elderly nurseryman who imparted to me, I’m sure, only a fraction of his wealth of knowledge on the subject.
After four or five half-hour sessions with him over a period of a few months (his teaching method: buy something, go home and try it, come back in six weeks), I learned what worked and what didn’t. I also learned that fertilizing is basically a school of hard knocks for both ego and wallet.
In the time since those valuable lessons, I have settled into a sensible frame of mind about fertilizing, one that leads me to offer plants regular, consistent, nutritious feeding of the kind one might offer a child. There’s no junk food or special diets or rolling with the latest trends: It’s just a sensible approach that works. And while I’d like to say my approach is totally organic, it isn’t – for reasons mentioned below.
Among the many important things the nurseryman conveyed to me, one of the most important was about patience. Fertilizers work best in warm, moist soils and so will act more slowly during the winter months. Be patient, he said, and don’t overfeed!
Through the years, I’ve developed definite preferences among the products I find on my local garden center’s shelves.
[ ] For lawns, I like Bandini Super Green. It comes in a white pellet form that dissolves quickly and can green up a lawn within a couple of weeks.
[ ] For foliage and overall plant growth, I use Blood Meal or Grow Power Plus. A while ago, I tried to stay organic, so I only used the blood meal and consequently learned an important lesson at my dog’s expense: Do not use blood meal in a yard where there are pets!
My dog was quite attracted to the fragrance of the blood meal and ate as much of it as she could. Let’s not get graphic and say simply that her digestive system eventually rebelled, after which I switched over to Grow Power Plus and found she had no interest in it whatsoever. I could still use the blood meal on my front yard, of course, but I’ve found that it’s easier just to buy one product.
[ ] For flower production, Bandini Rose & Flower Food works quite well. I also like Nurserymen’s brand, but I’ve had difficulty finding it consistently at the nurseries I frequent. Bandini also makes an acid-rich fertilizer specifically for camellias and azaleas. It’s best to use these specialty products instead of the general-purpose rose and flower food for any acid-loving plants.
[ ] For overall plant health, I use compost – usually Bandini Soil Builder – as a top dressing over any other fertilizers.
[ ] For systemic fertilizing – that is, to give plants what they need to get rid of pests and diseases while providing them with some nutrients at the same time – I often use a product called Wormgold. This stuff is made of worm castings and has only been around a few years, but it works like a miracle drug on plants infested with white fly and is a great fertilizer in addition to its healing properties.
Obviously, I use lots of Bandini products, but any other brand can be substituted so long as you pay attention to the N-P-K numbers and make certain your clients’ plants are getting what they need.
I prefer to do things in the easiest possible manner. When it comes to such routine tasks as fertilizing, my goal is to get my clients to apply consistent, ample nutrients to their gardens.
As a rule – and given the fact that I work in southern Califonia – I recommend fertilizing three times a year – on March 1, June 1 and September 1. I’ll sprinkle on some Grow Power Plus and Bandini Rose & Flower Food, just as one might sprinkle salt and pepper on food, moving methodically around the garden and working with one plant at a time. I’ll water lightly, then cover the whole garden (lawn excluded!) with Soil Builder. This layer aids the process by keeping moisture in the soil.
From that point on – until the next cycle – I water normally and regularly, depending upon the time of year and the weather. I don’t work the fertilizers into the soil, as experience has taught me that the slow leaching of nutrients over time is more beneficial to the plants than getting them to the roots immediately.
As I’ve also learned, there’s a distinct benefit to going easy on the fertilizer – everything in moderation!