April Gardening FAQ: How to Balance Perennials and Annuals

Credit: Flickr nipplerings72

Bright cineraria aren’t the longest-lasting annual, but they provide an array of vivid colours

The biggest question from gardeners in the month of April? How to balance annuals and perennials

Question: What kind of balance should I be trying to achieve in my landscape between annuals and perennials?

Answer: The thought of having to plant only once – and to have those plants just get bigger and better every year – makes it easy to understand the attraction of perennials. As a result, perennials have become mainstream over the past decade, with a huge selection available.

The perennial category now offers so many different species and varieties, with a diversity of leaf and blossom colours and textures, heights and fragrances – to touch on just a few of the features in this gigantic category.

Although perennials have a limited bloom time compared with annuals, there are varieties that bloom every single month of the year. Each one may only provide four to six weeks of bloom, but it adds up when you have a good mix with successive flowering times in your yard – moreover, many of today’s perennials deliver huge blossom size, amazing colour and rich fragrance.

So why choose any annuals when perennials are apparently the be-all and end-all?

Annuals are typically a spring-through-fall category of plant, because come late fall or early winter, depending on when the frosts arrive, they are done.

They die for two reasons – first, they have completed their life cycle of growing, blooming and setting or producing seed. Secondly, for the most part, they can’t tolerate cold and are killed by the frost.

The Difference Between Annuals and Perennials

Before I go into more detail, I should clarify that some of the plants we classify and use as annuals are actually perennials. Fuchsias and geraniums are good examples. They do not fall under the perennial category and are usually referred to as annuals, because they can’t tolerate the chilly temperatures and would simply die come winter frost.

Wim Vander Zalm will be answering your garden
questions on the Bill Good Show on April 24

But if you can store these plants over winter in a cool frost-free room that won’t get above 40F (5C), they can technically be classified as perennials. Dahlias, begonias and poinsettias are other examples of plants that could be considered annuals – or even disposables – in cool climates but in fact are perennial with a little TLC (and there’s a lot more in my book on this).

When to Plant Annuals

Annuals serve their own important purpose that works very well in unison with perennials in the garden. They can grow fast and furiously and for the most part bloom relatively soon – if not immediately – after planting. This offers quick coverage of large spaces to beautify a landscape. And, with just a few exceptions, annuals don’t stop blooming until fall or early winter.

So plant annuals in May to enjoy up to six months of colour in your garden. That’s an easy win over the six weeks of blossoms offered by the average flowering perennial.

So there you have it – both annuals and perennials have different roles to play in the garden. I use both: perennials for back-of-the-garden structure and annuals typically as fore-garden pick-me-ups to brighten borders and add spot colour throughout the summer.

I think a 50/50 split would have your yard and garden bright and beautiful 12 months a year – though I would use a heavier emphasis on perennials for year-round “good bones.”

Annuals or Perennials for a Pot

Annuals like residing in planters much more than perennials do. Annuals appreciate the extra heat a container environment gives their roots. Most perennials prefer growing in the cooler soil of an in-ground garden bed.

You can ask Wim your burning garden questions April 24 on The Bill Good Show at 11:05 am. Or catch him on Breakfast Television April 26 and on the Global Noon News May 2nd. And to meet him person, come to his book-signing at Art Knapp Plantland in Port Coquitlam on May 4th.

Which fruits and vegetables grow best in patio pots? When is the best time to cut back rhodos? These are just some of the 100+ burning questions that garden expert Wim Vander Zalm answers in his frank, friendly and often funny new book Just Ask Wim! Down-to-Earth Gardening Answers.