10 Shrubs & Perennials for All-Summer-Long Colour
One of the most common questions I get from customers is do you have anything that blooms all summer long? I’ll admit that it’s a big ask and the selection has not always been the greatest, but plant breeders have been working on this problem at breakneck speed. So here is a list of 10 hardy shrubs and perennials, some old and some brand new this year, guaranteed to provide you with that constant colour you are craving throughout the summer season.
1. Spiraea ‘Double Play Doozie’ (Zone 3)
Spirea have long been the backbone of low-maintenance gardens due to their drought tolerance (once established) and deer resistance, but here’s one that keeps blooming all summer long, even if you don’t deadhead. The colour starts in early spring when the new red-tinted foliage emerges and continues with deep magenta-pink blooms that really stand out at a distance. Add to that its compact nature (2-3’ tall and wide) and you have everything you could want in one shrub.
2. Leucanthemum x superbum ‘Snowcap’ (Zone 5)
Here’s a low growing (12-15” tall by 12” wide) Shasta Daisy that you will never have to stake and with a little deadheading you can have flowers from early to late summer. This durable perennial was first introduced by Blooms of Bressingham back in the 1980s and I have been using it in my garden designs since then. It is both deer and disease resistant and pairs beautifully with the rich blue of Lithodora ‘Grace Ward’, which also flowers all summer.
3. Syringa ‘Bloomerang Dark Purple’ (Zone 3)
We sell most of our lilacs in and around Mother’s Day when they are traditionally in bloom. The exception is the Bloomerang series of compact lilacs (4-6’ tall and wide) that flower heavily in spring and then blooms again from midsummer into fall. Expect very fragrant purple blossoms that attract both hummingbirds and butterflies but still manage not to bring in the deer. Any pruning should only be done immediately after the first flush of flowers has faded, which will slightly delay the repeat blooms.
4. Physocarpus opulifolius ‘Amber Jubilee’ (Zone 2)
An extremely cold-hardy foliage shrub that was bred in Manitoba by crossing Physocarpus ‘Diabolo’ and ‘Dart’s Gold’. Rounded white-tinted-pink blooms emerge from May to June, but it is the constantly changing foliage that is the real colour feature here. Shades of glowing orange, yellow, and coppery-bronze foliage are constantly changing throughout the season, shifting to a dramatic deep purple in the fall. ‘Amber Jubilee’ grows 5-6’ tall by 4’ wide and makes an interesting deciduous hedge option.
5. Nepeta racemosa ‘Walker’s Low’ (Zone 4)
This Award of Garden Merit winner was also perennial of the year in 2007. Despite the name, this Catmint does grow 2-3’ tall, but a compact variety called ‘Junior Walker’ (1-2’ tall) is also readily available. The aromatic grey-green foliage is smothered in lavender-blue flowers in early summer that attracts both pollinators and beneficial insects alike. It reliably repeat-blooms with deadheading and is also deer and drought resistant.
6. Hemerocallis ‘Stella D’Oro’ (Zone 2)
I think the best thing I can say about this Daylily is that it has been adorning my townhouse garden for seven years now, coming back better year after year and flowering its heart out with no dividing, fuss, or bother. Expect fragrant golden-yellow blooms from grass-like foliage (which goes dormant in winter) from early summer into autumn. It is compact (15” tall, 18-24” wide) and tolerates the worst conditions, including drought, poor soils, and slopes, and it can even grow under Walnut trees, which is usually a bit of a dead zone for most perennials.
7. Viburnum plicatum ‘Steady Eddy’ (Zone 5)
This new introduction from Proven Winners is essentially a compact (4-5’ tall and wide) version of the ever-popular ‘Summer Snowflake’. This deciduous shrub tolerates part to full sun and flowers heavily in late spring with a repeat bloom in summer. Expect striking purplish-burgundy autumn foliage and excellent deer resistance.
8. Azalea ‘Bloom-A-Thon Pink Double’ (Zone 7)
This semi-evergreen Japanese azalea smothers its canopy with fully double bubblegum-pink blooms in April. If you follow up with a light pruning right afterward, you will be rewarded with a generous rebloom on new wood in July, that continues into the fall. This variety grows 3-4’ tall and makes a great mass-planting.
9. Rosa ‘At Last’ (Zone 5)
If you’ve been waiting for a disease-resistant landscape rose that smells as good as it looks, then ‘At Last’ is the variety for you. Expect richly coloured sunset-orange blooms from early summer through to autumn. Just prune down by 1/3 in early spring (when the Forsythia blooms) and sit back and enjoy the colour for the rest of the season.
10. Hydrangea macrophylla ‘Endless Summer Twist-N-Shout’ (Zone 4)
This partial shade lover (3-5’ tall and wide) was the first repeat-blooming lacecap hydrangea. It bears deep pink to periwinkle-blue lacecap blooms (depending on soil pH) on contrasting red stems from early summer right into the fall. It can even be grown successfully in large containers (with consistent watering) and makes a stunning flowering hedge specimen.