When it comes to the colors of perennial plants in the garden, blue is by far the rarest and is also one of the many reasons that blue hostas are so popular, and the bigger the better. But how do blue-leafed hostas develop and keep that beautiful blue tint?
In a nutshell, blue hostas develop a glaucous waxy layer that develops as they emerge which helps to protect the leaves from harmful weather, and that blue wax causes the light to reflect in such a way that gives the hosta leaves that bluish coloring.
Blue hostas will get bluer and bluer throughout the years as they reach maturity, usually about four to five years.
There are several shades of blue and a lot of a hosta's final color depends on the specific hosta's characteristics. Some of those characteristics include:
The leaf shape of a blue hosta will also cast a different shade of blue on the leaves.
For instance, leaves that are twisted or heavily corrugated like the above Blueberry Muffins Hosta or that have deep veins will cast a deeper blue than hostas with smooth leaves.
Location, Location, Location
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.
How to Keep those Blue Hostas Blue!
To keep the best “blue” on your hosta, it is most important that you plant it in the right location. Morning sun and afternoon shade will give your blue hosta just enough sun to thrive and just enough shade to keep that blue color longer.
Most hostas perform well in such a location, but it is even more important with the blue ones.
Direct sun or too much sun can fade or melt off the blue wax making the leaves look green for the rest of that season. Also without that waxy layer, the leaves can burn more easily.
The above picture of a Carolina Blue leaf shows how rain can wash off that blue waxy coating. It may surprise you to know that the blue wax on the leaf can also be rubbed off with your finger.
You may notice the hosta leaves turning from blue to green all over or in spotty locations when there's much more rainfall than usual.
The Best Blues
There is much debate on which hostas are the “best” blue-leafed cultivars. While the answer to that is very subjective, here at Sunset Hosta Farm we have grown many types, and these are the blue hostas that we prefer to grow and sell.
Large/Very Large Hosta
Mature Size: Large Height 28” Width up 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.
Mature Size: Very Large Height 32” Width 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.
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.
Mature Size: Very Large Height 33” Width to 72”
It's not only a garden standout, but 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.
Mature 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 Sized Hostas
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.
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.
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.
Mini and Small Hostas
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.
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