Window boxes plantings not doing so well.

Hi--I was hoping to get some help in this forum. Last fall we put up four copper and wrought iron windowboxes. They are on the second story of our home and are south-facing. Each box is about four feet long. At the beginning of the summer I put MG potting soil in each box and planted each box with three electric pink geraniums, three very dark purple wave petunias, and two lemon symphony osteopermums. I've been fairly religious about watering and feeding (watering two to three times weekly as needed, feeding once a week with MG) and I've tried to stay on top of dead-heading with the geraniums. I was told that I would not need to dead-head the wave petunias or the osteopermums. Well, the geraniums are fine but the flowerheads are not as large as they initially were, the osteopermums have petered out and some of the petunias are "okay" and some have stopped blooming altogether. I'm very disheartened by all this--I made it very clear to the lady at the nursery that I needed plants with a lot of "pop" (the boxes need to be seen from 100' away) but they also needed to be relatively low-maintenance as I can't be doing tons of dead-heading or trimming to plants that are hanging out a window from a second story. Did I underfeed or overfeed? What did I do wrong? It's so frustrating to me when I see other people with petunias hanging out of their boxes with just waves and waves of blooms and mine have petered out. I've pretty much given up for this year, but any suggestions for next year would really be appreciated. Thanks!

Here's a picture of what they looked like--along with hubby!-- about a month ago...

Did the MG potting soil you used already have fertilizer in it? You mentioned that you have also been fertilizing once a week........

Too much fertilizer?

Just a thought....

carole

Do the plants look healthy otherwise? That would probably rule out watering issues. You definitely aren't underfeeding them, but it could be overfeeding a bit and sometimes that will discourage bloom. On the osteospermums--I've found mine keep blooming longer if I deadhead them, and I've also found they bloom more when the weather's a little bit cooler. On mine, I usually get great flowering out of them in the spring and early part of the summer, then they'll flower sporadically during the summer unless the weather's really hot in which case they won't bloom much at all. And with the petunias, you shouldn't need to deadhead, but a lot of flowers will tend to flower in waves, they'll bloom a lot for a while, then those flowers will fade and sometimes there's a little rest period before all the new blooms are there, you can't expect that they're going to be consistently 100% covered with flowers all the time.

Pretty boxes, Niere. Has it been very hot over the last month? I know some of my stuff takes the heat for awhile, but after weeks of over 90 degrees, it makes some look less "flattering".. I think it may be a combo of too much fertilizer and outside temps. I would cease the fertilizer until the weather cools a bit, at least.. I feed my containers with 1/2 strength 20-20-20 about 3 or 4 times a growing season. I'd also cut the petunies back some and they should come back and bloom once the weather cools (if it's been hot), if not I'd still cut them back and give them a 2nd breath. "They" say you don't have to deadhead million bells (caliobrocia) either, but I ususally snip back in July sometime, they seem to like the haircut and reward me with blooms. Window boxes on the southside would be totally fried by now in KS, without shade. We have big pots in direct sun, but usually water 2x a day, at least when it's this hot.

My osteo's rarely bloom all summer when they are in pots. Perhaps they are not growing very well because the roots want more room-there is too many in there. It really is hard to say. Perhaps it is just those particular plants. You could plant the same things in there next year and they could get huge. Don't give up hope though.

Now that you mention it--I never had much luck with them in pots either, they would grow a little and bloom some, but they looked a million times better when I took them out of the pot and put them in the ground.

Hi Niere~Nice house, love the colors you chose for the planters. I have had good luck with marigolds (which come in yellow as well as orange, but mine are orange) and Cherry Profusion zinnias this year in full sun. Dahlias, pentas and lantanas are some others that take the heat as well as pansies do. I would also recommend popping the pots directly into the planter, using a lightweight soil-less mix around them, and top-dressing with damp sphagnum moss (sheet moss). Then when they get tired of blooming you can switch them out easily, the moss helps hold moisture in. Hope this helps!