Expert: Kenneth Joergensen - 4/29/2004

Question
Hi,

I hope you can help.  I planted tulip and daffodil bulbs last fall, I live in the Chicago area.  On one side of my front walkway they bloomed as they should (the tulips are double tulips in a light pink color and the daffodils are yellow). On the other side of my sidewalk everything bloomed white.  I know they all came from the same package.  Do you know why this happend, and can anything be done for next year?

Answer
It is  one of those things which is very hard to explain. Both tulips and daffodils are very strong colored and will not change color depending on sun exposure, moisture, temperatures, or soil pH. Some plants, like hydrangea, will change from blue to pink as the soil pH rises. Other plants will bloom with clear colors in partial shade, but get "bleached" in full sun (lilies). Other plants again have best colors in cool weather (begonias).

If both the daffodils and the tulips are white and you are sure they came from the same package, I would consider having a soil test done.

University of Illinois Extension can perform this for a nominel fee. Usually you just mail in a small sample of soil and will receive a written test in the mail. Make sure you tell them that the flower bed is to be used for spring flowering bulbs as their recommendations for liming, fertilizing, etc will be based on this information.

Soil test labs in illinois (Chicago area):
http://www.urbanext.uiuc.edu/soiltest/

Also read this article:
http://www.urbanext.uiuc.edu/gardencal/extra/soiltest4.html

Soil pH extremes can be changed using gardens sulphur (to lower pH) and dolomitic lime (to raise soil pH). Do not adjust soil pH without having a soil test done first. Both are available from home improvement stores or garden centers.

It is not - normal - however for tulips or daffodils to change colors based on soil pH (or other factors).

Note: some daffodils ("Icefollies", for example) start off yellow and turn white as the flower ripens (matures). In sunny south facing areas next to driveways and roads, the soil temperatures tend to stay warmer than other locations and flowers may be in different 'stages' of development (thus the older flowers may be white while the newer flowers may still be yellow).

Azaleas for example typically go through this also turning from dark pink to light pink to white as the flowers mature. I have never heard this happen with tulips, however, although a light pink color can be less 'pink' in full sun, but it should not be extremely white either.

The best I can recommend, besides a soil test to determine if there is anything interfering with the plants, would be to try out another group of bulbs next year.

In any event, as soon as the flowers are spent (withers and petals start to fall off from the tulips) cut the spent flowers off at the top of the flower stem. Make sure you also cut off the puffy green swollen seed pods on the daffodils which form right behind the spent flower. Fertilize your bulbs 3 times per year: in early spring just as they poke through the soil, just as they flower (or are finished flowering) and again in fall (fertilize the general area). This should promote best possible chance for bulbs reflowering.

Note: do not restrict the green foliage (leaves) after flowering. the bulbs need the green leaves to conduct photosynthesis (e.g. convert the sun's energy into foodstuffs). Push it aside to plant annuals, etc but do not fold it up, braid it, or cut it off. The foliage will mature (ripen; turn yellow and wither) in 2-3 months by itself. At this time you can cut it off at soil level and dispose, but do not cut green foliage.

Good luck,
I hope you find out what happened with the bulbs.