We are often asked, “What is the bluest or best blue hosta plant?”
It is best to answer this question by first understanding why a hosta is blue. The top layer of a blue hosta leaf is covered with a glaucous coating that provides a blue appearance to the leaf. This coating is often written as being a leaf wax or leaf bloom. This coating is also on fruits including blueberries and plums. The more glaucous coating a leaf has the bluer the appearance.
Hostas are generally bluer when they first emerge as this is when the leaf bloom is developed. Hosta ‘Fragrant Blue’ (which ironically is not fragrant) has an uncanny ability to send up new foliage late into the season which helps this hosta stay blue longer. Blue hostas plants are also generally bluer as they mature and the leaves generate a thicker leaf bloom.
Why Is My Blue Hosta Not Blue?
Now that we know why blue hostas look blue, we can figure out why they sometimes don’t look blue. The glaucous coating on the hosta leaf is susceptible to the elements of Mother Nature.
- The biggest problem with the leaf bloom is that direct sunlight and heat can break down the bloom and decrease the blue color. You may often hear that blue hostas should not be grown in sun. Although direct sunlight should be avoided, blue hostas do their best with some morning sun or a filtered light situation.
- Another way that the leaf bloom disappears is from rainfall and overhead watering. The constant pattering of water on the leaf breaks down the bloom and turns a blue hosta green. Customers are often surprised when shown that you can wipe the blue color off of the leaf with your fingers.
Great hybridizing efforts have led to hostas with very thick leaf blooms that stay blue almost the whole growing season. Other blue hosta varieties emerge a brilliant blue but are blue/green to green by July. Blue hostas hold their color better in cooler climates and we have read articles of blue hostas being green by the end of May in the south.
There are also in our opinion different shades of blue. Some look silvery blue and others have a deep blue.
So, What Is The Bluest Hosta?
We have seen numerous posts on garden forums and everyone has their own opinion!
Here is a list of our favorites among the blue hosta plant varieties that we offer.