Despite being a massive thorn in the side of many property owners, the path to ridding an area of weeds typically doesn't seem too murky – just roll up your sleeves and start hand pulling, and eventually, you'll win out...right? Unfortunately not. Some weeds simply cannot be dealt with this way. Five of the most stubborn weeds that we deal with in the Calgary, AB area are Canada thistle, common tansy, diffuse knapweed, leafy spurge, and toadflax. They're so stubborn and resilient that they will continue to sprout no matter how many hand-pulling sessions you do, so the best course of action is to opt for chemical intervention by a professional.

1. Canada Thistle

An image of a Canada thistle weed among a lawn in Calgary, AB.

Canada thistle is an aggressive weed that establishes a hearty root system and can grow a little over 1.5 metres tall. It's most recognizable when its flowers change to fluffy seedheads that can be white, purple, or pink. The fluffy tops of Canada thistle, much like a dandelion, become airborne and spread seeds across the land. Because of their hearty root system, hand pulling will not do the trick – they will continue to produce new shoots and spread to new areas.

2. Common Tansy

The common tansy can grow close to 2 metres tall and with leaves similar to a fern, forms multiple stems that grow out from its base so that, by appearance, it almost passes as a shrub. Its trademark is flowers that look like yellow buttons. Common tansy will develop a rhizome, or continuously growing horizontal underground stem that puts out lateral shoots at intervals, to spread out and take over an area of land. This rhizome will continue to spread the weed unless it's completely eradicated.

3. Diffuse Knapweed

The leaves of diffuse knapweed are covered with short, dense grey hairs and it features clustered flowers that are white, pink, or purple. The big impact of diffuse knapweed comes in its seed production – after flowering, dried plants may break off at the base of the step and travel with the wind, distributing seeds as it goes and spreading the weed further. Its high seed production allows it to easily overtake an area and suppress native vegetation, making it a threat to any landscape.

Diffuse knapweed is in the sunflower family, although people are typically much less thrilled to see this in their landscape than a true sunflower.

4. Leafy Spurge

Leafy spurge weed infecting an area of a customer's home in Calgary, AB.

Featuring blue-grey leaves with bright greenish-yellow flowers, leafy spurge can grow over 1 metre tall and loves to invade pastures, grasslands, prairies, and more. It develops an extensive underground stem and root system, allowing each plant to produce large clumps of shoots that overtake other plants quickly. If a leafy spurge seedpod is disturbed in any way, whether via wildlife, wind, water, or otherwise, its seeds can travel up to 6 metres from the base seedpod to continue the weed's spread.

5. Toadflax

Toadflax grows waxy leaves that can be heart-shaped or blade-like depending on which variety of toadflax you have. It grows up to 1.5 metres tall and can have a single stem or a more bushy presentation. Its roots can penetrate up to 2 metres deep and 3 metres wide in the soil, dominating space in a landscape easily. It can easily resprout from these roots, so hand pulling, cutting, or tilling are widely ineffective at permanently removing this weed.

Think you might have one of these stubborn weeds invading your lawn? Call us today to show them the door!

If you suspect your lawn may be victim to weeds, even if it isn't one of the most stubborn weeds above, the best route to ensure you take back your landscape is to call a professional. That's where we come in! At Prestige Outdoor Services, landscaping isn't just a job for us – it's a lifestyle. We are passionate about everything lawn and landscape and provide top-notch landscaping services, including weed control, to homes and businesses in Calgary, Airdrie, Chestermere, and surrounding areas in Alberta. We would love to help you next! Call us today at (403) 250-8464 to schedule your next service and show weeds the door.