Why Use a Seed Mix?

The traditional dominance of lawns in our landscapes and green spaces is in decline, faced with drawbacks such as high water consumption, intensive use of chemicals and low biodiversity. Although certain areas such as sports fields or playgrounds still benefit from the use of turf, more and more people are adopting alternatives such as the diversified lawn, which incorporates a mix of grasses and other plants, such as wildflowers or clovers. Even so, any lawn, no matter how ecological, requires occasional mowing and can’t compete with other types of plantings in terms of their contribution to species diversity.

We can, of course, replace lawns with more traditional perennial and shrub beds or native plant gardens, but this takes time and money. When it comes to large-scale landscaping, the cost can be prohibitive. So, many turn to seed mixes to establish new plantings or wildflower meadows, and the horticultural industry has responded by developing new products to meet this demand.

Benefits of Using a Seed Mix

Using seed mixes is less expensive than buying potted plants, and requires less effort to plant. It’s also simpler when it comes to choosing plants, since the selection is made by professionals, usually to guarantee continuous flowering from spring to autumn. Some mixtures are generalist, while others are designed for specific conditions, such as dry or wet soils, or for renaturalization using native plants. It’s important to remember that when you have a variety of annuals and perennials, the ones that suit your garden conditions establish themselves better, and when conditions change, another plant is there to fill the space. As in nature, diversity means resilience.

Plants from seed often have a greater capacity to adapt to their local environment, since they begin their life cycle in the specific conditions where they will grow. This can make them more resilient to local stresses such as disease, pests and climatic variations. They also have more genetic variability, which brings higher diversity within a plant population and can contribute to better overall ecosystem resilience and adaptability.

Seeds or Potted Plants?

However, seed mixes, while practical for covering large areas quickly and cheaply, do have some disadvantages compared with planting perennials and shrubs. They require more regular maintenance when first established, to help balance competition between the desired species and weeds, which is crucial to the long-term success of the mix. Full establishment can take a few years, so the visual effect is delayed. Mixes can also lack uniformity and precision in design (rather an advantage for those who like a more natural look) and germination is sometimes uneven, requiring reseeding.

Potted plants generally have higher survival rates after planting, as they are sold with a well-developed root system and are sometimes grown under controlled conditions to enhance their robustness before sale.

We have to weigh up the pros and cons, and choose what’s right for us and our garden.

Choosing a Seed Mixture

Soil type is crucial to the successful application of a seed mixture. Test the soil for texture, pH and fertility. Some seed mixes require poor, well-drained soils, while others prefer richer, moister soils, and still others are destined for less sunny locations. There are recipes for each of these conditions.

Another category of mix is designed to attract beneficial animals to our gardens. There are products for pollinators, butterflies, granivorous birds, and even specifically for monarch butterflies, considered an endangered species in Canada.

Some mixes are designed for very specific, technical conditions. I’m thinking here of bank and slope stabilization, or specifically for green roofs. In addition, there are products designed to awaken the senses, such as flower mixes that are a sight to behold, with fragrant plants or edible flowers.

I even found a mixture for use in seed bombs, those little balls of seed, potting soil and clay designed to be planted in neglected or unkempt spaces, without necessarily having permission to do so.

There’s no shortage of choice, but if that doesn’t satisfy you, you can design your own mixes, but we’ll come back to that another time!

Seed Mix Composition

Most mixes are composed of annuals, biennials and perennials. Annuals offer rapid growth and abundant flowering for immediate ground cover and a quick injection of color, ideal for filling gaps while waiting for other plants to become established. Biennials, meanwhile, bridge the gap between seasons with their two-year life cycle, offering foliage in the first year and flowering early in the spring of the second. Perennials bring longevity, requiring less maintenance once established, and contribute to the permanent structure of the garden with their visual interest that extends beyond flowering. This mix creates a dynamic garden that evolves with the seasons, offering a diversity of textures and colors while supporting a rich ecosystem for wildlife.

Shelter Crops

Shelter crops can also be found in these combinations. These are mainly annual grasses added to seed mixtures, which play a crucial role in promoting rapid germination and growth, helping to protect the soil against erosion and monitor seeding success. They act as an indicator to identify areas where seeding may be incomplete, enabling rapid corrective action. Although these plants do not reappear after the first season, as they are generally mowed before seed production, their roots and stems remain in place over winter and continue to protect the soil, creating a kind of underground net that maintains the soil structure. It is important to regulate the density of these plants to avoid harming the development of other species in the mix. Oats and ryegrass, for example, are shelter plants.

Has this given you a taste for it? I’ll be back next week with a simple method for installing a seed mix.