Hostas and Sunlight

Growing the right hosta and in the right sun conditions is worth researching and testing!   Hostas are “shade tolerant” but some varieties are also more “sun tolerant” than others.  Like any plant, hostas need some sun to survive and thrive. 

Our HostaSearch™ Database suggests the light tolerance of many hostas (see heuchera table for heucheras) .   

To learn about hosta colors and influences to hosta colors, visit our Hosta Colors page.  

See our sun tolerant hostas for sale.

Hostas will grow in most light conditions, given enough water, but they may not thrive, have good color or the color you desire, or have their best foliage in every light and heat condition.   Depending upon the genetics of the plant, the same plant can have often three or more different leaf colors, and they can change during the growing season, depending upon various factors.  And, don't forget the colors of the surrounding plants can also enhance certain leaf colors.  

The two clear signs your hostas are growing in too much sun or not getting enough water are browning at the tips of outside edges of the leaves and seeing dull color or faded spots in the leaves.  But, leaf colors can and will change as well depending upon the sun.

To help determine the best location for a hosta variety and to provide the leaf color for that particular plants that you desire, ask yourself the following questions:

1)  What are the plant genetics or characteristics of the plant?  Keep in mind the 40 or so original species hostas evolved primarily in Japan but a few evolved in China and the islands of South Korea.  These 40 or so species varieties created the gene pool for the remaining 8,000 or more cultivars.   In general, hostas with thick leaves or have fragrance, are totally yellow, yellow and white variegated and some colors of green will tolerate the most sun.

2)  What type of light will the hosta be grown in?   Examples:  morning, afternoon, evening, dappled or filtered light or full sun?  Full sun in the morning and evening hours will be less intense than the afternoon sun.   You can use ornamental grasses, trees, shrubs, arbors, pergolas, trellises, shade clothes, and climbing vines to provide extra shade. Consider making your own shade by purchasing 50% to 60% shade cloth from your local nursery supply store.   Remember, you can always move your hostas to different locations if necessary – if they are in containers or even growing in the ground.

3)  What type of wind and sun will my plants receive?   Consider planting hostas with larger leaves in deeper shade and out of hot winds.  Hostas with those characterists can lose moisture from their leaves faster in those conditions through a process called transpiration.   It is like perspiration in humans.   Pores in the hostas leaves, called stomata, open up and allow water to escape and wind will accelerate that moisture loss.

4)  How will the light change during the course of the growing season?   Some growing areas may be shadier or sunnier during different times of the year due to the angle of the sun in relation to your trees, roof line, etc.   Learn more about your sun and shade conditions here.

5)  Where is my garden located on the earth?   Southern gardens get more direct, intense sun over a longer period of time.  Certain varieties of the hosta family perform better in southern locations than others.  As an example, the species Hosta plantaginea is the only fragrant hosta of the original 40 or so "species" hostas.  It is native to the more southern parts of China and is far south in the overall range of species hostas.  Most of its off spring can be grown in full sun and are more heat tolerant.  They can be grown in zones 3 to the northern parts of zone 9A.   

6)  How much water will my hostas receive at different times of the year?  Hostas prefer at least 1” of moisture pure week (but are fairly tolerant).   They can go into “heat dormancy” when the temperatures are too hot or they do not get sufficient moisture for the heat, sun and soil conditions.   Heat dormancy means the discontinue growing.  However, in many cases cool fall temperature and moisture will bring them out of dormancy.

7)  Soil structure and slopes.   Will my soil retain moisture or will it drain fast?  Obviously, fast draining, sandy soil requires more moisture.  Take time to amend your soil.   Slopes may not allow adequate moisture to penetrate your soil.   Hosta roots can grow down to 18” deep.   Make sure the water seeps all the way down to the bottom roots, realizing water may run off the hosta’s foliage or evaporate in over- head trees branches etc.  Applying mulch can help with moisture retention.    Learn about planting hostas and soil preparation.

8)  What is the pH of the soil that my hostas will be grown in?   Hostas prefer an acidic soil with a pH of 5.7 to 6.8.   Hostas grown in basic soils with a pH of 7.2 or more may become more yellow because the plants will no longer be able to uptake certain nutrients and the leaves will suffer from chlorosis, a yellowing of the leaf color.

9)  Do you want blossoms?  Hostas need some sun to produce outstanding blossoms and some hostas more sun than others.   In particular, hosta plantaginia and off spring of plantaginea need more sun to develop their blooms.  Hosta plantaginea ‘Aphrodite’ needs possibly the most sun of all hostas, but their HUGE and beautiful blooms are worth the effort.    Fragrant hostas do need 4 to 6 hours of sun to develop their fragrance.  

10)  Elevation.   They higher the altitude the more intense the sun will be.  Plan accordingly and test.

General sun/leaf color rules:  

Darker colored hostas have more green chloroplasts in their leaves and thus need less sun light to create photosynthesis that creates the sugars for the plant to thrive.  

Lighter green or yellow hostas often require more sun-light.  

Medio-variegated (white centered) hostas can tend to burn in lots of sun unless the hosta has thicker leaves (often found in tetraploid hostas - most hostas are diploids).   When placed in full sun they can chlorophyll levels can increase and cause the leaves to pick up a green cast and look less variegated.  So, morning sun or late afternoon is recommended for white variegated hostas with thinner leaves.

Yellow or yellow centered hostas need at least two hours of direct sun to look their best.  Without enough sun yellow hostas may stay green instead of turning yellow or yellow margins may not lighten to cream white.  They generally are the most sun tolerant hostas.

Full sun:

Hostas with green, chartreuse or yellow leaves are able to handle more sun provided there is adequate moisture for the roots. Depending upon the variety, hostas can grow in full sun but need plenty of water to survive. However, full sun can make the hosta burn and brown later in the season, especially if the roots are not getting enough moisture. If you grow hostas in stronger afternoon sun, make sure you water them more. Hostas that can tolerate more sun are noted in our HostaSearch™ Database. Hostas grown in more sun will create more roots, grow faster, and have more leaves, but they will also have longer and narrower leaves, and colors that may look more bleached or washed out. See the color difference in two 'May' hostas grown in different light conditions. Occasionally, the hosta leaves can bleach and lose color without burning. This video shows this phenomenon.

Bleached Leaves

Shade:

Shade varies in intensity. Light cast by a high tree canopy is only partial shade and ideal for hostas. Hostas with blue-green leaves and white variegation, whether in the center or margins, do best in shaded areas.  

Sun and Slopes:

Owner Tom Carlson shows the stunted growth of a Hosta 'Mr. Big' planted side-by-side due to lack of sun. 

Gray and blue hostas:

Hostas are gray or blue because the specific cultivar (type of hosta) has a gene that creates extra crystalline wax on the top and/or bottom side of the leaf. Direct sun can cause this wax to melt off, which causes the hosta to show its underlying green color. Some varieties have more intense blue color and some hold their blue or gray color longer  into the sesaon.   The wax might also rub off due to high winds or water dripping off a roof.

Gold hostas:

Generally, gold hostas will tolerate more intense sunlight better than other hostas. Most yellow hostas also require more sun  to bring out their full color potential. See H. 'May' leaf example above.

Fragrant Hostas | Hosta Maintenance | Yellow Hostas

Seasonal Hosta Care | Hosta Garden Information