Expert: C.L. Fornari - 7/10/2003

Question
Hello,
How do I keep my flowering annuals in pots flowering? They keep their leaves and lose the flowers and do not grow back more flowers, all the colorful petals just fall off. I've watered when I should and have used several brands of fertilizers for flowering annuals. The geraniums are losing, and so is the lobelia, and also the pansies. Just healthy green, but no color.
Thank you
Teresa

Answer
Teressa,
Several things might be going on depending on the particular plants.  Let's take it one at a time.
Geraniums need four or five hours of dead-on sun in order to bloom well, but interestingly, if they are in hot sun all day, they may not flower as well as if they are in the sun for half of a day.  Also, they bloom better when slightly pot-bound, so if you put them in a larger pot recently they may wait to bloom until they have grown a bit more.  Geraniums (and most annuals) bloom best when fertilzed with a fertilzer that is higher in nitrogen, or one with equal percentages of nitrogen, phosphate, and potassium.  In other words, DONT use so-called "blossom booster" fertilizers that have a high middle number (phosphate) but use something like a 10-10-10 or Peters All Purpose Plant Food (20-20-20).

Lobelia and pansies are cool weather annuals - if it is hot were you are they will naturally peter out about the fourth of july.  They are both longer blooming in part shade (because they stay cooler) but no matter where they are planted, they will stop blooming in hot weather.  (The Lobelia in Alaska does very well!)  If it is NOT hot where you are, then they are probably not getting enough light.

I hope this helps!
C.L.