By Ava Green

Is there anything sweeter than the scent of Lilacs in the spring? These beloved shrubs are remarkably easy to grow and will reward you with weeks of fragrant blooms for little or no effort. But a bit of attention can make a big difference, especially if you’ve noticed your blooms getting smaller or fewer with each passing year. 

To help your lilac put on its best show, keep these steps in mind:

• Plant in full sun, at least 6 hours of direct sunlight a day, in well-draining soil
• Water newer plants during prolonged periods of drought until established (the first 3 years)
• Feed your lilacs annually with a balanced fertilizer (10-10-10, for example)
• Follow spacing instructions and prune yearly. Pruning is a very important step, and it’s well worth it.

Knowing When to Prune is Key

Timing is everything when it comes to pruning your lilacs. After the blooms fade, you have a two-week window to prune before the shrub sets its buds for next year's flowers. Yes, they set buds this year that will bloom next year! Pruning lilacs in the fall or the early spring risks cutting off all of the flower buds for the following year. Mark your calendar and prune promptly after flowering.

It also helps to understand how lilacs grow: Younger, thinner lilac stems produce more flowers. Older, thicker stems are more prone to disease and pests. Keeping this in mind will help with pruning decisions.

How To Prune Young Lilacs

If your lilac has been in the ground for less than three years, leave it alone; it doesn’t need pruning yet. Many young lilacs won’t bloom during those first few years.

After three years, once your shrub is established, begin by removing just one of the thickest, oldest stems down to the ground every 2 years. This gentle approach prevents the shrub from becoming overgrown while encouraging newer, flower-producing growth. 

How To Prune Older, Overgrown Lilacs

If your lilac has been neglected or grown out of control, you have two options:

Option 1: Gradual Rejuvenation

Begin by removing any damaged stems, as these invite pests that can harm the entire shrub. Next, remove only the largest, oldest stems by cutting them right down to the ground. The key is to remove no more than one-third of the living wood (dead stems don’t count toward that total). Leave the younger, thinner stems intact so your shrub can still bloom the following year. Repeat this process each spring for three years, and you’ll gradually restore the shrub to its full, flowering potential without sacrificing a single bloom season.

Option 2: Full Cutback

For a severely overgrown lilac that has been largely ignored, a complete cutback is often the most practical solution. Cut the entire shrub as close to the ground as possible, either in early spring or immediately after blooming. Yes, this breaks the general rule of never removing more than one-third of live wood, but lilacs are remarkably resilient and respond well to this kind of hard reset. By the end of summer, you will have healthy new stems of three to five feet tall. While the shrub won’t bloom for approximately three years after a full cutback, the long-term results are well worth the wait.

Deadheading Your Lilacs

Deadheading, or removing spent flower clusters after the blooms fade, is a simple task that’s separate from pruning, and can be done during that same two-week post-bloom window. When you trim off faded blooms, the plant redirects its energy from seed production toward building bigger, healthier buds for the next year. It takes only minutes and can make a meaningful difference in the size and abundance of next year’s flowers. 

A Note on Lawns and Lilacs

If your lilac grows near a lawn, be mindful of how much fertilizer you’re applying to the surrounding grass. Lawn fertilizers are typically high in nitrogen, which encourages lush leaf growth, but too much nitrogen reaching your lilac’s roots will suppress flower production.

Worthy Rewards

Lilacs are remarkably long-lived, often outlasting the gardens and even the homes they were planted beside. So whether you’re nursing a young shrub through its first few years or breathing new life into an old, overgrown beauty, the effort you put in now is an investment that will keep rewarding you, and perhaps generations after you. Every single spring!

While many gardeners in Southern Ontario follow the popular planting date of May 24th, when we’re usually safe from frost, you may be surprised to know that April is not too early for certain plants!

Once the ground has thawed and is workable, there’s plenty you can start growing. In Zones 6a-6b, this usually happens around four weeks before May 24th. While frost is still a possibility, many cold-tolerant plants not only survive a light frost but thrive in cooler weather. To check if the soil is ready, simply dig up a handful and squeeze it. If it sticks together, it’s too wet to work with—wait a few more days for it to dry out. Once the soil is ready, it’s time to plant those cool-weather crops!

Cool Weather Vegetables

Radishes: Radishes are fast-growing and perfect for planting in April because they love cooler weather. Sow them directly from seed.

Peas: April is the perfect time to plant peas outdoors as soon as the soil is workable. Soak pea seeds in water for 8-10 hours before planting them to help germination.

Lettuce, Spinach, Arugula, Asian Greens (Tatsoi, Mizuna, Pak Choi and Leaf Mustard) : It’s best to sow seeds for leafy greens or plant seedlings early in the spring as they will grow quickly in cool weather. Plant more seeds or seedlings every 10-14 days for a succession of greens until hotter temperatures make them bolt (go to seed) and become bitter.

Potatoes: Seed potatoes can be planted in mid to late April as soon as the soil is workable.

Onions: Plant onion sets or seedlings that have already been started in early spring and enjoy a harvest in late summer or fall.

Carrots: Plant carrot seeds in April, and they will be ready for harvest later in the spring or early summer. They take a little longer to grow, but planting early gives you a head start. You will enjoy carrots all summer long by planting more seeds a few weeks later.

Tip: It’s a good idea to keep some frost protection like row cover handy for lettuce, peas and spinach just in case the temperatures dip below zero.

Bonus: Many garden pests, like earwigs and slugs, are still overwintering in April and won’t feast on your tender plants.

Cold-Tolerant Flowers

Pansies: Add a pot of Pansies to cheer up a front porch, and it instantly feels like spring! Plants can go into a sunny spot in the ground when temperatures reach 7-21 celsius and are regularly staying above freezing.

Violas: These cool-weather flowers can withstand light frosts and are perfect for containers or for planting in garden beds

Gladiolas: Even though the weather is still cool, this resilient summer-blooming bulb can be planted in a sunny area of the garden in April. 

Bonus: Pansies and Violas also love cool weather in the fall.

Perennials, Trees and Shrubs

Two to three weeks before the threat of frost has passed, many potted perennials, shrubs and trees, either dormant or with leaves, can be planted. (If you’re not purchasing from us, be sure to check whether the plants were grown outdoors or acclimated to cooler temperatures and ensure they’re hardy enough for Southern Ontario.)

While perennials, trees, and shrubs can be planted throughout spring, summer, or fall, the combination of warming soil and increased rainfall in spring creates the perfect conditions for successful transplanting.

Come into Eising Garden Centre to see the many seeds and plants available for you to add to your garden in April!

Additional Resource: Landscape Ontario provides an excellent online Tree Planting Guide.