With their striking, sculptural flowers, dahlias bring a touch of drama to the garden across summer and autumn. Given their popularity in floral arrangements, it’s no surprise that many dahlia enthusiasts seek to maximise blooms.
A common question, then, is where to position dahlias in the garden for optimal flowering. Are dahlias full sun plants or shade plants?
Getting the balance right
Most plants need sun and water to thrive.
While the optimal amount of each depends on the individual species, many plants are able to survive quite well in less-than-ideal conditions.
Even among these more adaptable types, though, flowering can be given a big boost through positioning that simulates a plant’s natural environment.
It’s important to consider not only the regional climate of origin, but other aspects of the plant’s habitat.
For example, the type of surrounding plant community (e.g. woodland, desert) can affect how much sun and water is accessed.
Where do dahlias grow naturally?
Dahlias originated in mountainous, warm-temperate regions in Mexico, Columbia and Guatemala, so they have an affinity for warmth and sun.
However, they occur mainly in oak and pine woodlands, which means they’ve adapted to surroundings that provide protection from moisture loss in harsher conditions like strong heat and drying winds.
The perfect dahlia: sun or shade?
Do dahlias like sun? Yes. Will dahlias grow in shade? Yes to that, too.
That said, dahlias flower best in spots with at least six hours of sunlight that are also able to stay moist. In Australia, true full sun can give rise to dryness. So when it comes to growing a perfect dahlia, shade is actually a necessity in many parts of the country.
Where should I plant my dahlias?
In general, dahlias do best in a position with full sun in the morning and shade in the afternoon. In Australia, an east-facing position is usually your best bet for achieving this.
Why the distinction between morning and afternoon sun? In short, afternoon sun tends to be more intense, and it can be downright harsh during Australia’s hot summers.
While some plants revel in full sun exposure, others (like dahlias) favour the gentler morning hours for their daily sunlight fix.
Dahlias don’t like to dry out, which is why they should also be protected from strong winds.
Embrace the morning sun
Position your dahlias well, and be rewarded with beautiful blooms this summer. While you’re planning your east-facing bed, why not try, one of these beauties alongside your dahlias?