IT'S that time of the year again when the "feel the need to feed" groupies are out in force fertilizing and liming their gardens.
I am not against feeding plants in principle. I am however against feeding plants just because everyone else does it or because there's some sort of tradition. The long-held myth that plants need to be fertilized in spring likely started from some sort of proactive marketing campaign originating in the 1950s or 1960s which then got stuck in our collective consciousness as the right thing to do. Spring fertilizing is not a tradition, it is a science that requires knowledge, experience and prescribed application based on the results of a soil test.
Many lawns for example get fertilized and limed every year for no good reason. The best time to fertilize the lawn is in June after the spring flush of growth has finished and spring rains have slowed or ceased. June feeding allows the fertilizer to actually be taken up and not leached away by spring rains into the ocean to cause red tide.
What's that you say? Your lawn looks very green after fertilizing. How do you know it is the fertilizer causing the green growth and not the stored reserves in the root? Exactly, you don't. As for liming lawns every year, that old myth is foisted upon us by an industry focused on driving sales and not problem solving. Not that I am against making money, we all need to eat. But let's apply just a little bit of the knowledge and training we are supposed to have obtained from college, university or industry training and actually verify with a pH test that liming the lawn is needed. Lawns do not need to be limed every year, unless a pH test indicates low pH. And just because it rains does not mean the soil's pH is dropping. Healthy soil will stabilize its pH if there are healthy populations of micro-organisms and mulch is maintained on the soil's surface year round with only a marginal drop in pH over the longer term.
Trees and shrubs are also regularly fertilized each spring when they do not need to be. As a matter of fact, most new growth from leaf buds occurs as a result of stored energy in the bud. And because leaf bud growth is basipetal, meaning growing from the tip of the stem down to the roots, new shoots cannot even take up fertilizer until contact with the root has been made. Not to mention that most plants, especially deciduous plants, store food reserves in their roots over the winter to use for spring growth. So all of that expensive fertilizer thrown down in April or May on the garden or lawn is largely useless, mostly wasted and leaches into the water table and ultimately the ocean where it damages marine life.
Perennial plants in particular generally prefer a well structured and organic rich soil to grow in versus growing in some kind of puffed up state of being constantly fed which makes them weak, soft and predisposed to pests and disease. Don't listen to marketing propaganda telling you that plants must be fed every spring to help with recovery from the long winter. That's just propaganda and rubbish. What did all of the plants in the world do before fertilizer was invented? Die? I think not, plants grew just fine for millennia without fertilizer.
So what's a gardener to do with all of this conflicting information? Feed? Not feed? Feed a little just in case? If you suspect your plants have a fertility problem which would externalize as some sort of chlorosis or other nutrient deficiency symptom, you should get a soil test done to determine the actual problem.
If your plants have solid green leaves of a good size and no noticeable health issues then they are healthy. Like all problems, accurate diagnosis has to be done before you can determine the most effective course of action to fix the problem. Without an accurate diagnosis of a problem or determination of actual need, you might as well throw your money into the ocean for all the good it does.
Many years ago I used to be addicted to fertilizing in spring, probably due to the indoctrination I received in college where we were taught to fertilize and manage the garden to attain maximum productivity. Unfortunately, "managed landscapes" have a higher percentage of "management issues" versus those landscapes that are grown holistically using intelligence, problem solving and testing. So what am I doing with all the money I saved by not fertilizing and liming this spring? I am buying mulch and more plants.
Todd Major is a journeyman horticulturist and chief horticulture instructor at the University of British Columbia Botanical Garden. For advice contact him at [email protected].
