Gardening success means avoiding these common mistakes

An image showing "volcano mulching" applied around a young dogwood tree. The practice is detrimental to trees and often results in their slow death. Photos: Jessica Damiano/AP

Much of gardening is learned by trial and error – for many, mostly error.

Planting a shade-lover in full sun isn’t likely to breed success, nor is letting your emotions run rampant at the nursery. But we’ve all been there, and the good news is we can learn from others’ mistakes as well as our own.

First, we need to admit we’re not perfect.

I’ll go first: Many years ago, I sowed a handful of morning glory seeds at the foot of the arbour surrounding my front gate. Labelled a “fast-grower” and “self-sower”, I was sure the vine would provide the lush foliage, flowers and instant gratification I wanted.

Unfortunately, it did its job too well, and these days, I spend about a half hour every week during summer pulling up seedlings that pop up as far as 50ft (15m) away.

Ditto for my mint-planting debacle, which I smugly thought I could avoid by planting in a container set into the garden bed. Sure, that first summer was all sunshine and mojitos.

But mint is a pot-jumper, and it spread with abandon via seeds as well as roots that emerged from the planter’s drainage holes and travelled underground.

By the third year, I had to dig up the entire bed to remove it. I learned quickly to recognise invasive plants, even if they aren’t labelled as such.

Here are five other common gardening mistakes – and how to avoid them.

A drip-irrigation system installed around plantings.

Not testing soil

Proper soil pH is the No. 1 ingredient for success, but there’s no one-size-fits-all number to strive for. Tomatoes, for instance, grow best in soil with a pH between 6.0-6.8. Blueberry plants, on the other hand, will likely turn yellow and produce scant, if any, fruit if the pH is higher than 5.5. That’s because nutrients are available to plants only at target pH levels, which vary for each type of plant.

Test kits are relatively inexpensive and widely available at garden centres. Pick one up and test the soil in each garden bed individually, as the pH often varies even on the same property. A reading of 7.0 is considered neutral. Anything lower indicates acidic soil; higher, alkaline.

The path of least resistance – and the best course of action – would be to select plants best-suited to your garden conditions. But suppose you need to reconcile your love of tomatoes with your soil’s low pH value?

In that case, you can incorporate dolomitic lime (follow package directions) to raise the level. And just as lime raises the pH – or increases the alkalinity – of soil, amendments such as elemental sulfur will lower it (opt for pelleted over powdered, and again, follow directions).

Watering incorrectly

Most garden plants require 1-1.5 inches (2.5cm-3.8cm) of water per week, either from rainfall or supplemental irrigation. But leaving the work to a sprinkler, while suitable for the lawn, puts shrubs, annuals, perennials and edibles at risk. Mould, mildew, fungal and bacterial diseases spread as water becomes trapped between plant parts or splashes from infected leaves to healthy ones.

Instead, snake a porous soaker hose or drip-irrigation system made of perforated plastic tubing over the soil surface. That will direct water to roots, where it’s needed, instead of leaves, fruit and flowers.

Skipping compost

Compost is a gardener’s best friend: It improves the drainage of heavy clay soil, increases the moisture-holding capacity of sand and adds high-quality nutrients.

Incorporate generous helpings into new beds and borders, or add an amount equal to half the removed soil to individual planting holes.

Wrong plant, wrong place

A plant labeled as needing “full sun” will likely disappoint if planted in part shade, and vice versa. And no matter how much you hope otherwise, “drought tolerant” will never mean “likes poorly-draining, soggy soil.”

Selecting plants suited to your growing conditions will result in a better-looking, healthier garden that requires less care and maintenance.

Improper mulching

Mulch retains soil moisture, suppresses weeds and helps keep soil temperatures even, so it’s an essential component of every garden. Mulching improperly, however, can kill your plants.

Always opt for a natural material such as shredded bark, wood chips, straw or pine needles, which will enrich the soil as they decompose.

As a matter of routine, apply 2-3 inches (5cm-7.6cm) of mulch around plants. Keep the material three inches (7.6cm) away from trunks and stems to avoid blocking air circulation and locking in moisture, which would result in rot.

And never pile up mounds of mulch against tree trunks. The practice, often called “volcano mulching”, prevents air circulation and locks in moisture, which leads to suffocation and rotting over time.

To avoid this, make sure the flare at the base of the trunk is always visible. – AP