Perennials are supposed to return every year, but, exactly when they do depends on the plant.
Each has its own preferences in terms of its growing climate. All perennials are divided into groups based on what season they flower.
So, When do perennials return?
Spring-blooming perennials return in March/April.
Late spring perennials return around May.
Summer bloomers return around July/August.
Late Summer bloomers return in September
Autumn bloomers return around October.
Winter perennials return in December when the temperatures cool.
Detailed below, you’ll find a gardeners guide to perennials through the seasons and information detailing the differences between short-lived perennials and long-life varieties, herbaceous perennials, evergreen vs woody plants that return each season, and with examples of seasonal perennial plants.
Designing a Perennial Garden for Flowers in Different Seasons
There’s so many perennial flowers available!
With careful planning – you can go to town and really brighten the look of your garden. They will be flowering every month of the year. It’s a great way to achieve the pop of color you’re after!
Just like annuals, and even houseplants, perennial flowers have their preferences. Some like it in full sun and relish in the heat of summer, others like the shade, and your winter bloomers love the cooler weather.
They won’t spring to life until the temperatures drop around December.
That said, winter bloomers are reliant on the cooler temperatures so while it used to be that you could expect winter bloomers to be putting out bursts of colour from December through to mid-February, if by the start of February the weather’s feeling like Spring, they could just go into early dormancy.
The same applies to all types of perennials. As the weather changes, so do the plants behaviour.
Outside of their comfort zone, they go into a period of dormancy.
Typically, the garden season begins in early Spring.
Spring bulbs are the ones to use for flowers in March/April.
Here’s some of the most popular perennials.
- Examples of spring flowering bulbs are tulips, daffodils, hyacinths, and bluebells.
As the weather warms, you can have some late spring perennials that’ll bloom around May.
- Examples of late spring perennials are alliums, erythroniums, and bearded irises.
For the summer months, that’s when the majority of herbaceous perennials are on full show with early summer flowers emerging in June.
- Examples of summer blooming perennials are salvias, peonies, coneflowers, and geraniums (hardy varieties).
There are some plants such as salvias that can flower from June through to October, however, to get that prolonged flowering, it requires deadheading when the colours begin to fade around mid-summer.
This can give you a second burst of colour lasting late into the summer.
This is also the time for hanging baskets to be in their full glory.
Fun fact: One of the longest blooming perennials is yarrow.
Bridging the gap between summer and autumn are the late summer bloomers.
- Examples of perennials for late summer return include asters, goldenrods, and marigolds.
Into the autumn is when the late season bloomers come out to play.
- Examples of Autumn perennials are hylotelephium, chrysanthemums, and Rudbeckias, particularly, the coneflower variety (Rudbeckia fulgida var. sullivantii ‘Goldsturm’). Some varieties of Rudbeckia are annuals or biennials.
These tend to last up until late November, at which point they go to ground with winter perennials resurfacing around December.
- Examples of winter perennials are violas, pansies, snowdrops, primroses, and certain species of hardy cyclamen plants.
Short-lived Perennials vs Long-Life Perennials
The definition of a perennial plant is one that lives for longer than two years.
Sadly, nurseries and the local garden center won’t tell you how long they live. If yours was looking grand last year, then failed to reemerge this year, it’s (probably) not your fault!
There will always come a point when a perennial dies.
No perennial lives forever.
Short-lived perennials tend to flower profusely for their first few years, then the show stops.
You can get lucky because the vast majority will self-seed and you’ll get new plants growing sporadically wherever the seeds germinate.
Failing that, the only other way to prolong the show of short-lived varieties is to take cuttings and propagate them, or alternatively, harvest the seeds and start again.
Generally, you’ll find that the long-blooming perennials are the ones that are short-lived.
They put so much energy into flowering early and for a while that it’s unsustainable after several years pass.
Long life perennials tend to last upwards of 7 years, so if your plan is to design a perennial garden to save the costs of replanting annuals or replacing biennials, plants such as peonies, daylilies, and the Oxeye Daisy will save in the long-run.
Tender Perennials Vs Hardy Perennials
Tender perennials can be thought of as a hit or miss.
They may survive the winter months if they are protected with a thick mulch or some other organic matter to protect them from frost.
For the inexperienced gardener, hardy perennials are your best bet.
The term hardy is used to describe a plant that can survive over winter, although some will require a mulch to protect the roots against a hard freeze.
Herbaceous, Woody, and Evergreen Perennials
Herbaceous perennials go to ground whereas woody perennials remain above ground just without their flowers when they are out of season.
Evergreen perennials retain their leaves throughout the year when the plant isn’t in bloom.
Woody perennials are similar to herbaceous plants; the only difference is (obviously) the wood.
Rather than having soft stems, these have branches or vines that don’t die back to ground level. The advantage to these in a perennial garden design is their size.
Because the wood stems remain and only the leaves die off, they have a head start for vertical growth and spread every season.
With climbing perennials, you could have a pergola covered with honeysuckle, or large walls entirely covered in Boston Ivy.
If you plan to use a woody perennial as a covering for a garden structure such as a pergola, be sure that the structure is sturdy enough to support the weight.
Wisteria is a common climbing plant used with pergolas, but the heavy weight of the branches can make it too heavy for light-weight structures, such as thin trellises.
To summarise:
A perennial garden can be easier to maintain, and cheaper than annual plants and biennial plants, but not all are equal.
Some are long-blooming perennials, others short-lived, then some are tender (requiring protection from the elements), and some that won’t stand a chance in the winter, requiring overwintering in a greenhouse, or indoors.
With long-lasting perennials, you should expect to plant once, then with relatively little maintenance, have perennial flowers return annually, and reliably for close to a decade.
The only things to last longer than long-lasting hardy perennials are shrubs and trees, both of which are much higher maintenance.
Another good shrub for all year round colour I recommend is the rose. I’ve written a guide on how to prune the climbing rose here.
Hopefully now you can fill all the empty spaces in your garden with different varieties! Ready to start growing perennials for next year!