One of my clients recently told me that they had never fertilized their lawn or garden plants before.
They asked a simple question:
“Which fertilizer should I use, and when should I apply it?”
The answer I sent in an email may also be helpful for people who are new to fertilizing their garden.
Lawn Fertilizer Basics
There are many different lawn fertilizers, but you don’t need to make it too complicated.
In most cases, a regular lawn fertilizer made for grass will work just fine.
Lawn fertilizers usually contain three main nutrients:
Nitrogen (N) – helps grass grow green and healthy
Phosphorus (P) – supports root development
Potassium (K) – helps plants resist disease and stress
Understanding Fertilizer Numbers
On fertilizer bags, you will usually see three numbers, such as 20-0-3.
These numbers represent the ratio of:
Nitrogen – Phosphorus – Potassium
Grass usually needs more nitrogen, so fertilizers with a higher first number are commonly used for lawns.
Many lawn fertilizers have numbers like 20-0-0 or 20-0-3, where phosphorus and potassium are low.
For most home gardens, simply using a standard lawn fertilizer sold at garden stores is perfectly fine.
Liquid vs Granular Fertilizer
Another choice is how the fertilizer is applied.
Some fertilizers are mixed with water, while others come in granular form.
Granular fertilizer is usually easier to apply and releases nutrients slowly over time, which is why I usually recommend it.
You can buy lawn fertilizer at places like:
- Home Depot
- RONA
- Costco
- Canadian Tire
- local garden nurseries
How Often Should You Fertilize Your Lawn?
In most cases, fertilizing 2–3 times a year is enough.
A simple schedule could be:
April – first application in spring
June – optional second feeding depending on lawn condition
October – fall fertilizer
Fall lawn fertilizers often have different numbers, usually with a bit more potassium to help grass prepare for winter.
Fertilizing Garden Plants
Garden plants also benefit from fertilizer.
For most home gardens, fertilizing once or twice a year is usually enough.
There are many types of garden fertilizers, but if you are not sure which one to use, a simple all-purpose fertilizer works well.
In my own work, I sometimes use different fertilizers depending on the plant and season, such as:
- evergreen fertilizer
- flowering plant fertilizer
- root-support fertilizer
But for beginners, all-purpose fertilizer is a good starting point.
Like lawn fertilizer, granular fertilizer is usually easier to use than liquid products.
Example Products
Here are some examples of fertilizers that work well.
Spring & Summer Lawn Fertilizer
https://www.rona.ca/en/product/scotts-turf-builder-granule-lawn-fertilizer-30-0-3-145-kg-02345-1267102
Fall Lawn Fertilizer
https://www.rona.ca/en/product/turf-builder-32-0-10-fall-lawn-fertilizer-105-kg-03217-12675277
All-Purpose Garden Fertilizer
https://www.rona.ca/en/product/sta-green-all-purpose-slow-release-fertilizer-8-12-6-3-kg-4001202-58735007
Written by Andy Lee
Owner of Andy’s Landscape Inc. – Landscape Contractor in Maple Ridge, BC