Petunias

September 23, 2017

I have Supertunias in concrete pots with a drip line. They get watered every day for about 10 minutes. They are in full sun all day. They have become very leggy and thin with very few leaves. What am I doing wrong?  Also had Wave Petunias in another concrete pot that were stunning and almost overnight they turned brown and died.  There got heavy afternoon sun and the sprinkler watered them daily. Again, what am I doing wrong?

Petunias can remain beautiful all season if they are fertilized regularly, and I mean every week or two during the growing season.  This year, we had a lot of rain, so there are several annuals that got leggier than normal and maybe not as floriferous.  For the supertunias that are still living, give them a haircut—cut them back by half and begin fertilizing.  They are quite cool tolerant and will even tolerate some light freezes.  For the quick dying pot, I would suspect maybe too much water and they died from a root rot.  Clean out the container and sterilize, make sure it has a good drainage hole and plant with something for fall and winter color.

February 1, 2017

I have a very small Mexican Petunia. When and where should I plant it? Is it invasive?

I am surprised you have a Mexican petunia or Ruellia growing indoors.  They are a perennial plant that typically go dormant for the winter and then re-grow the following season. They are very heat and drought tolerant.  The standard Mexican - Ruellia brittoniana can grow to be 3- 4 feet in height and if given ample moisture, it can be aggressive. In drier sites, it is better behaved.  The dwarf varieties that grow only 8-10 inches tall rarely get aggressive. They both do best in full sun.  They do need some moisture to get established, but well-established plants are drought tolerant.

May 28, 2016

I have petunias planted in a container on the front porch that gets afternoon sun.  They have already become leggy and the top where I pour water looks smashed down.  There are still a few blooms.  I deadhead them.  Do I need to "cut them back" someway?  Will they become "bushy" again with lots of flowers?  Or, do I just need to consider their time spent and get new ones to plant?

Most of the newer varieties of petunias should bloom all summer without the benefit of deadheading, but they are heavy feeders.  Since yours are already leggy, I would do two things. I would cut back the existing plants and add another new one in the pot with these. Then fertilize weekly and keep them watered and they should stay full and bushy and bloom all summer. 

April 30, 2016

I purchased petunias last year at three different locations and failed to keep the tags. I was planning to replace the dead plants with pansies late in the fall as usual but about half of my petunias were still going strong after freezing temperatures hit. I even had blooms on Christmas Day! This spring they have grown larger and are covered in blooms. Is there such a thing as a perennial petunia? I sure would like to have more of the same this summer.

In a mild winter it is not unusual for petunias and callibrachoa (their smaller blooming cousin) to overwinter. We had an almost non-existent winter, and many have made a comeback.  You obviously did a great job fertilizing your petunias throughout the growing season, since they will often stop blooming if they don’t get enough nutrition.  In Little Rock, we did not have a hard, killing frost until after the New Year.  I still had blooms on my dragonwing begonias, petunias and even tropical hibiscus until January 7.  It was an unusual season, but not one we can be guaranteed every year.

(March 2010)

I have a neighbor that needs some help with her nine window boxes.    Her window boxes are 36" long, 7 1/2 " wide and 6 " deep, and they have a nice layer of moss all around, and no plastic liner.   There are 4 on the first floor and 5 on the second.  They get some morning sun, the 4 on the right more - maybe 4 hours, and the 5 on the left maybe 2-3 hours.   Watering is not a problem, but her house is a dark red.  Light pinks, yellows, white and any shade of green, especially the silver ones would look good.  She would like a cascading effect on the top 5 as they are so high up.  Would perennials work? That way she wouldn’t have to replant every year.  Any suggestions you have would be wonderful. 

There are two reasons I would probably opt for more annuals than perennials.  First, I wonder how long perennials would last in these window boxes.  The soil temperature will get much colder in these moss lined wire containers than in the ground, the containers aren't that large, so the volume of soil is smaller, and they will be elevated, so my guess is that most perennials would freeze or at least go totally dormant during the winter.  Another downside for flower potential, is that perennials have a defined season of bloom and then they have a period of just green growth.   Do you want them to have color in the winter months as well?   How awful would it be to use annuals? For the summer season, Silver falls dichondra would be fantastic in them as would the sweet potato vine--there is a pink and white variegated one, or even the Blackie would look good.  If you want to try a perennial, try variegated Vinca major or the variegated needlepoint ivy.  Creeping jenny would also be nice, but the bright yellow of the foliage might clash--you may want to go with the green one.  For color in the pots that is more upright, try the Zahara zinnias, bubblegum pink petunias or angelonia.  These are all annuals, but give you way more color in a season than perennials would.  Some of the smaller ornamental grasses may also be a perennial option for filler.

(July 2010)

I have some petunias planted in urns and a hanging basket. They all have grown over the edges and are hanging down, which would be beautiful but they are looking ugly and woody. Is it the hot weather?  Should I trim them back, if so how much?

 If the hanging baskets aren't large, this often happens to petunias with hot weather. I think they often do better for home gardeners in the ground.  They need a lot of fertilizer in containers to keep full and healthy.  Petunias are heavy feeders in any situation, but we water pots so much that we leach out the nutrition quickly.  Weekly applications of a water soluble fertilizer are needed for petunias in pots to look good.  Cut them back by half or if the ends look good, add some more plants to the top of the container to fill in there.

(February 2010)

I have a neighbor that needs some help with her nine window boxes. Her window boxes are 36" long, 7 1/2 " wide and 6 " deep, and they have a nice layer of moss all around, and no plastic liner.   There are 4 on the first floor and 5 on the second.  They get some morning sun, the 4 on the right more - maybe 4 hours, and the 5 on the left maybe 2-3 hours.   Watering is not a problem, but her house is a dark red.  Light pinks, yellows, white and any shade of green, especially the silver ones would look good.  She would like a cascading effect on the top 5 as they are so high up.  Would perennials work? That way she wouldn’t have to replant every year.  Any suggestions you have would be wonderful.

There are two reasons I would probably opt for more annuals than perennials.  First, I wonder how long perennials would last in these window boxes.  The soil temperature will get much colder in these moss lined wire containers than in the ground, the containers aren't that large, so the volume of soil is smaller, and they will be elevated, so my guess is that most perennials would freeze or at least go totally dormant during the winter.  Another downside for flower potential, is that perennials have a defined season of bloom and then they have a period of just green growth.   Do you want them to have color in the winter months as well?   How awful would it be to use annuals? For the summer season, Silver falls dichondra would be fantastic in them as would the sweet potato vine--there is a pink and white variegated one, or even the Blackie would look good.  If you want to try a perennial, try variegated Vinca major or the variegated needlepoint ivy.  Creeping jenny would also be nice, but the bright yellow of the foliage might clash--you may want to go with the green one.  For color in the pots that is more upright, try the Zahara zinnias, bubblegum pink petunias or angelonia.  These are all annuals, but give you way more color in a season than perennials would.  Some of the smaller ornamental grasses may also be a perennial option for filler.

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