Lily Flower Colors During Hot Weather

'Amarossi' - during a foggy August morning.

 Some elements can be manipulated, others cannot.

The color intensity of lily flowers can be variable from year to year and garden to garden, based on soil pH, weather and the type of fertilizer used for nutrients.

Whether your soil is "sweet" (alkaline) or "sour" (Acid), you can make temporary adjustments to pH in several ways.

In the Western States, where soil is naturally more acid, no further treatments are necessary because most lilies are happy with our native conditions.  Martagon lilies, being of European descent with more alkaline soil conditions, would like the addition of lime to raise the pH.

Common sulfur, ferrous sulfate and aluminum sulfate are quick "fixes" for soil that is too alkaline, but regular use of compost and manure is also a good choice because it will also improve your soil's texture.
 

Trace Minerals applied every few years also seems to help to brighten flower color,  plus helps your plants utilize fertilizer more effectively. 

We cannot do anything about the weather, but if you plant purebred Oriental lilies, pink and melon colored Trumpets, or pink colored Asiatics - all which have thinner cell color layers -  in afternoon shade, it will help keep flowers from being bleached by the sun before the buds open.   Cold and wet springs can also tweak colors, flower size and stem height.  Lilies can be heat sensitive during unusual weather - so with a short "spring" that goes directly into warm summer - stems will be shorter and flowers smaller.  During long mild spring weather - such as in the Northwest most years - stems will grow taller and might need staking, especially if planted in light shade. 

'Circus' during warm weather seems to keep the melon accent on each petal quite well  in our acid soil.  Very warm climates, especially coupled with more alkaline soil, the flowers may tend to lighter in color.

Sun plays a BIG factor in the color green.  'Tribbano' - possibly available this fall - is a stunning lime green when the blooms first open, but within a few hours of sun, all open flowers change to an even creamy white with green nectaries.  During 90-100 degree weather, the green tint might not show at all.

'Graffity' is another easy to grow Asiatic lily that open green with purple splotches and speckles, then mellows to creamy yellow in warmer climates or during hotter summers.  Planting in light shade will help to maintain the green hues.

 'Muscadette' during very cool weather (low 60's) shows a nice bright pink stripe down each petal and dark red pink spots.

During periods of warmer weather (85-100 degrees), 'Muscadette' will be paler in comparison, with even its speckles not being quite as pronounced.

Because many of our gardening friends are in warmer climates than us, this lighter colored image will also be used in future catalogs.

(UPDATE: 8.5.13)

After three days of drizzle, rain and overcast days, our summer reverted back to the normal foggy August mornings that stay cool, until about 11am, before the sun emerges and the temperature rises.  Notice how the pink centers are darker when the days are in the low 70s, but not as intense when the days are colder (first photo)?  'Muscadette' has strongly upfacing flowers when first planted, but older plants will also have outfacing blossoms.  

These three examples of 'Muscadette' clearly show the role the sun plays in color intensity of Oriental lilies in the garden.  Locating the sweetly scented Orientals in afternoon shade does help to retain the pink hues.