Question
I have two hanging baskets of petunias which are facing southwest.  Every year
they look full and beautiful with abundant flowers.  By the end of July the stems
and leaves have turned from dark green to a lime green color.  The flowers are
still abundant however.  What can I do to improve the color of the leaves and
stems?  I fertilize daily with an extremely diluted amount of Miracle Grow.

Answer
Roberta,
If the plants are flowering they are getting enough sun so we know that isn't the problem - is the soil being kept constantly wet? When petunias are kept too wet the leaves will turn light green or even yellow. Although you don't want them to go so dry that they are wilted, you don't want to keep the pot constantly saturated either. Use the weight of the basket as your guide - if it's still very heavy then don't water - water when the basket is light but before the plants wilt.

I'd also give it a full strength dose of fertilizer once a month, or give the basket a time-release product such as Osmocote Indoor Outdoor or Proven Winners Time Release. The problem with using a very dilute solution every time is that a good deal of that fertilizer runs out the bottom.  To fertilize, water the basket in the morning and leave it for several hours to get hydrated - then in the evening give it a dose of fertilizer, mixed according to the directions or SLIGHTLY higher. Never fertilize a thirsty plant with full strength fertilizer.

You may want to read the article that is currently on the splash page of my website  www.gardenlady.com - it is about petunias.

I hope this helps!
C.L.