Annuals: Why We Love Them and Tips for Success

Author: Claire Leduc, Master Gardeners of Lanark County

After months of winter and pandemic restrictions, gardeners will be eager to get outdoors and enjoy their gardens. Annuals are sometimes passed over as expensive because they only last one summer. But when you grow them, you start to appreciate their many positive qualities.

First, what is an annual?

A true annual is a plant that completes its life cycle in one year. It produces pretty flowers that attract pollinators and, as a result, seeds to secure the next generation. It dies once it has completed a single reproductive cycle. But there are many “tender” perennials that we treat as annuals because they cannot survive our winters.

Why We Love Annuals

Because of their beauty and versatility.

During their short life, annuals spend less energy building their root system while spending more toward the production of flowers and seeds. For this reason, they need a bit more maintenance than other plants. Their shallow root system can quickly dry up during hot summer days.

Annuals allow gardeners to experiment with different colours and textures from year to year. They can be used to complement the shrubs and perennials already in a garden or they can stand on their own and add drama when used in mass plantings or larger drifts.

In addition to being beautiful and colourful, many are edible. Nasturtiums are well known as colourful additions to salads or fancy dessert presentations. Calendula is also easy to grow and is delicious and very pretty when added to various dishes.

Because they attract beneficial insects

Beneficial insects are a gardener’s best friends. They pollinate flowers and increase the yield in vegetable gardens. They prey on pesky insects, help decompose plant material to create healthier soil, and are also an important source of food for birds and other wildlife.

Native plants are usually best at attracting beneficial insects, but annuals can still play an important role when combined with a variety of plants in the garden. Many annuals bloom early or late in the season when other plants are not in bloom. Bumblebees and bees emerging from their winter hideouts benefit from the nectar of early bloomers. They can also be observed at the end of the season on the annuals that are blooming until the bitter end.

Tips for success

Soil Matters

Some annuals do better in humus-rich soils, while others thrive in poor soils. Nasturtiums and cosmos are examples of plants that do better in lean soils. In rich soils, they grow large leaves and long stems but few flowers. Hold back the fertilizers in these cases! In most cases, annuals appreciate regular fertilizing to ensure season-long blooming.

For container planting, garden soil is too heavy. It becomes compacted and restricts the flow of water and oxygen to the roots. A “soil-less” mix sold specifically for containers is the best choice.

Space Matters

Ready-made hanging baskets are often packed with pretty annuals for visual effect, but it doesn’t take long before the plants become root bound and the arrangement starts to look tired. This leaves gardeners wondering what they have done wrong. To avoid this issue, try repotting in larger baskets soon after you bring them home or split into two hanging baskets with extra soil. You’ll have two for the price of one, and you will ensure your annuals have enough soil for the whole growing season.

When choosing containers, go as big as you can. Annuals can quickly become root bound in a container that is too small.

Light Matters

When shopping for annuals, be sure to pay close attention to the light requirements of each plant. Many annuals do well in full sun, while others prefer some afternoon shade, or even full shade. To ensure happy plants, choose your annuals according to the location you have in mind.

Water Matters

Containers require daily checking, and frequent watering if grown in a sunny location. They won’t need such frequent attention if grown in shade or semishade. If the top few inches of soil are dry, and if the container feels light, it’s time to water. Water as required, and thoroughly until water runs out of the drainage holes. Annuals grown in flowerbeds are less crowded than in containers, and don’t need as much attention once established.

Go Big!

Have you ever heard a gardener say that they wish they had bought fewer plants? Whether for visual effect or to attract beneficial insects, think large. It takes a lot of energy for pollinators to go from one location to another to find the necessary nectar and pollen. When you plant in large drifts or masses, pollinators exert less energy to find the pollen and nectar. To attract a greater variety of beneficial insects, plant a variety of flowering plants.

Deadhead Regularly

Deadheading refers to snipping or cutting spent flowers. Because annuals complete their life cycle once they have set seed, deadheading encourages annuals to produce more flowers. It keeps your annuals looking fresh and full. While you are at it, make yourself some beautiful bouquets to enjoy indoors.

Master Gardeners’ Favourite Annuals

• Zinnia for the range of colours and sizes available. Attracts beneficial insects. Sun.
• Cosmos thrive in poor, dry soil and hot, sunny sections of the garden. Great for beneficial insects.
• Nasturtium because of their endearing foliage and generous blooms, not to mention the edible leaves, flowers, and seeds. Thrive in average to poor soil and sunny location.
• French marigold is known for being easy to grow, drought-tolerant and great companion plants. Sun.
• Calendula for the edible petals and leaves, and very long blooming even after a light frost. Sun or part-sun.
• Lantana for the long-lasting and interesting bloom colours. Good for beneficial insects. Sun or part-sun.
• Morning glory for the glorious flowers and ease to grow in poor soil. Sun.
• Snapdragon for the colour variety and kid-friendly flower shape. Sun or part-sun. Sweet alyssum for its sweet scent and ability to attract beneficial insects. Sun or part-sun.
• Salvia for their long blooming period and for being pollinator magnets. Sun or part-sun.
• Begonia, especially ‘Dragon Wings’, for bold leaves, pretty flowers, anda freshh citrus flavour. Part-sun or shade.
• Fuchsia for their pretty flowers. Part-sun or shade.
• Lobelia for the rich jewel-tone colours and delicate appearance. Part-sun or shade.
• Coleus for the wide range of leaf colours. Partsun or full shade.
• Browallia for its trouble-free nature and interesting bluish flowers. Part-sun or full shade.

As you can see, annuals are fun and easy to grow. From year to year, they add colour and variety. The concept of “green thumb” is a bit of a myth. It’s all about knowing a few simple rules that will make your plants thrive and survive no matter what nature throws at them. Be adventurous and try new arrangements. Beneficial insects will thank you, and you’ll enjoy the annuals’ beauty for many months.