Thursday, November 2, 2023

Sun's Effect on Blue-Leafed Hostas

Closeup of Blue Hawaii Hosta's blue leaves

The Sun's Effect on Blue Hostas

Blue hostas require the most protection from the sun because the blue color is actually a waxy coating on the top and or bottom side of the leaves. The leaves are actually a shade of green, but the waxy coating makes them appear those great shades of blue.

Too much sun can cause the waxy coating on blue hosta leaves to melt off and expose the green leaf underneath. This is the reason it is recommended that blue hostas are planted in more shade than other hostas.

The blue hostas are always very popular and there are several shades of blue-leaved hostas. Blue hosta leaves will become bluer and bluer each year as they move to maturity, usually about four to five years. 

Hosta with blue leaf foliage

What's the best siting for a blue hosta?

The best siting for hostas with blue foliage is some morning sun and afternoon shade. If your blue hosta is keeping its blue color through most or all of the season, it's obviously in the right spot. 

 Keep in mind, though, that blue hosta cultivars differ greatly in their blue coloring and in how long they will hold their blue color into the season.

Epsom Salt for
Beautiful Hosta Leaves

Things to Consider

Hard or prolonged rain can wash off the waxy coating and give the hosta the appearance of green spots like you can see in the above picture. It is normal to see color changes in the hosta leaves throughout the growing season as the sun grows more intense. These changes are temporary for the season.

Hostas with thicker substance to their leaves can take more sun as they can absorb and hold more moisture. Big Daddy is a great example of this. Conversely, hostas with thinner leaves are more susceptible to sun-scald.

The leaf shape of a blue hosta will cast a different shade of blue on the leaves. For instance, leaves that are twisted or corrugated or that have deep veins will cast a deeper blue than hostas with smoother leaves.

There are hostas that are “Sun Tolerant.” If your hosta is advertised as such, it is your best bet for placement in some sun. When it comes to blue hostas, though, the blue leaves will turn green during the season when placed in some direct sun.

Blue Hostas


Blue hostas grown in warmer locations may only keep their blue hue until late June, while in the northern climates, the leaves will remain blue longer.


Potting Mat

      The Best Blue Leafed Hostas

There is much debate on which hostas are the best blue-leafed hosta cultivars. 

Large/Very Large Hosta

Big Daddy Hosta in Pot

Big Daddy Hosta

Mature Size: Large  Height 28”   Width up to 40” Chalky blue cupped leaves that retain their blue color for most of the growing season. White to pale lavender flowers appear in mid-summer.

Blue Angel Hosta in Nursery Pot

Blue Angel Hosta

Size: Very Large Height 32” Width up to 70"
One of the bluest hostas. The blue leaves are heavily textured and heart-shaped. They form a nice-sized flowing mound. White to lavender flowers appear in mid-summer. Blue Angel will also draw in the butterflies.


Blue Hawaii Hosta

Mature Size: Very Large Height 30” Width to 42” 

These thick blue hosta leaves are upright, vase-shaped, and slightly cupped and corrugated. Blue Hawaii holds its blue color well through the season. It is also slug resistant. White blooms are fragrant. Great as a specimen plant or in a container.

Blue Umbrellas Hosta

Blue Umbrellas Hosta

Mature Size: Very Large Height 33”  Width to 72”
It's not only a garden standout, it's also a vigorous grower and sun and slug tolerant. It will greet you in the spring with nice blue umbrella-shaped leaves and pale lavender flowers that appear in the summer.


Krossa Regal Hosta

Size:  Very Large Height: 33" Width to 70" This hosta can't help but get noticed. Krossa Regal has frosty gray-blue leaves that are vase-shaped with slightly wavy edges. Spikes of lavender bell-shaped flowers on top of 5' scapes appear in late summer. Krossa Regal will get wider as it matures, so give this one plenty of space. Great when used as a specimen plant or in a container. Pair this one with a creamy variegated hosta like H. June for a dramatic garden statement. The thick leaves make it slug resistant, too.

Medium Hostas

Blue Cadet Hosta

Blue Cadet Hosta

Mature Size: Medium Height 15” Width to 38” The blue heart-shaped leaves are heavily textured and have a nice mounding habit. They have a vigorous growth habit that will fill an area quickly. Tubular lavender flowers rise above the foliage mid-summer. Great as a border plant or ground cover.

Blueberry Muffins Hosta

Blueberry Muffins Hosta

Mature Size: Medium Height 15” Width to 40” Blueberry Muffins has large, thick, puckered heart-shaped powdery blue leaves. The petioles are speckled with a mauve color which makes a nice contrast. Strong, reliable grower. Bell-shaped lavender flowers appear in mid-July.

Carolina Blue Hosta

Carolina Blue Hosta

Mature Size:   Medium  Height 18”   Width to 32”
This sport of 'Halcyon' and 'Riptide' makes a medium-sized mound of light blue rounded leaves that hold their color through most of the season even in warmer climates. Pale purple flowers shoot up in July and August. Tolerates morning sun very well.


Halcyon Hosta

Halcyon Hosta

 Mature Size: Medium   Height 18”   Width to 36”

A very popular steel blue hosta with heart-shaped leaves and heavy ribbing. Very sturdy, compact, and reliable grower. Looks great in containers, too. Holds that beautiful blue color well through the season. One of the bluest, and this one's been used to create many sports.

Small/Mini Blue Hostas

Blue Mouse Ears Hosta in Hypertufa Container

Blue Mouse Ears Hosta

Mature Size: Mini   Height 8”   Width Up to 19”
Hosta of the Year 2008 for good reason. The medium blue/green mouse ear-shaped leaves are nothing short of adorable. Outstanding lavender to white lily-like flowers atop graceful stalks. Great for rock gardens. Also slug resistant. 


Hostas are such a forgiving perennial, they can easily be moved to a more suitable location until it's in just the right spot. If the leaves do turn green for a season, not to worry. The blue waxy coating will return as the hosta emerges the next season.

The blue colors of hostas have been described in many ways, including deep blue, powdery blue, intense blue, icy blue, silvery blue, and chalky blue. But no matter which term you use, with the right care and placement, blue hostas will add a peaceful, cooling feeling to your perennial shade garden.

Because there are so many variables to consider, you could follow all of the above suggestions and still not be successful in achieving an exact leaf color.

One of the great things about hostas is that they're easy to dig up and move to another location. And there's always the possibility of planting your hosta in a pot. Then you can move it around until it's in just the right spot for the coloring you're after.

Hostas continue to be a favorite perennial plant for plenty of reasons. Their toughness, beauty, ease of care, and variety of great leaf colors and shapes make them one of the best plants for a shade or semi-shade garden.


Garden Kneeler - Extra Wide

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