What could be causing my petunias to die? They are in full sun in a container 18 inches in diameter. I planted three Wave petunias in late May, three more about the 4th of July, and another three at the end of July. Only three in the planter. New planter, with Miracle Grow soil and rocks in the bottom for good drainage. Still they keep dying. This happened last year also. I have been successful in growing beautiful petunias for 30 years.
There are a few things that could be causing this. The most common would be underwatering. Sometimes underwatering can be caused by not watering often enough. With most weather in the summer, you should be watering daily. If it gets over 85 F, you should be watering twice a day. Underwatering can also be caused by over dry potting soil. Potting soil that is over dry will actually repel water, so even if you seem to water often enough, the soil simply does not absorb it. If you have switched potting soils, this may be the cause. If you suspect that this is the case, soak the containers (plants and all) in a bucket full of water until air stops coming out of the soil.
There are other reasons it could be happening, but let us know what kind of symptoms you are seeing before they die. That will help us pinpoint it better.
Purchased early this year from my local nursery I planted my few Sweet Williams in a ready made bed for a display in the coming summer. Sadly up to now there is not one blossom; in fact, they have multiplied and are looking very healthy I must say. It's the end of season almost, so do I dig them up and sling them or what?
If they truly are a petunia, then the season is lost and you should just throw them out. I suspect the location had too much nitrogen as this would cause lots of growth with little flowering.
There is another type of plant called Sweet William that is a type of Dianthus. This plant is a biannual and if what you planted were these, you should leave them in the ground and give them some bone meal to help them with blooming next year.
Where abouts on a plant would I pinch trailing pertunias?
With petunias, you don't need to be exact. They respond well no matter where you prune them, but the technical advice on pinching is to pinch 1/3 to 1/2 of the branch down right above a leaf node (where the leaves grow from the stem).
My petunias start dying out after it starts getting hot here in the valley. Is there anyway to make them last longer?
This is common but avoidable. Increasing water will help and many people also choose to prune back their petunias by 1/3-1/2. This encourages the plants to start to bush out again.
If they are in containers, try moving them to a shadier location and also definitely increase watering to 2X a day.
When I water my hanging petunia basket, is it okay to sprinkle over the blooms? The basket is hanging very high and I want to sprinkle with a wand; is this okay to water over the blooms?
Watering the foliage or blooms of plants is usually not a good idea, as it can lead to fungal infections, which thrive in moist conditions. If you must water with a wand, try to keep the water stream/spray towards the base of the plant, taking care to keep the foliage/blooms from getting too wet.
Even though I deadhead my petunias, by pinching out the spent flowers, my plants still get very leggy. How can I have fuller and prettier petunias?
This is standard petunia behavior, especially in warmer weather. You can give them a bit of a haircut though. Try cutting about a third of the legs back by half. When new growth begins, cut another third and so on. This should rejuvenate the looks of your petunias and encourage a bushy growth rather than a leggy one.
I have planted many petunias around my home. Most of them are doing very well but one section I have planted are not bushing out, just growing straight up with only one stem and the leaves do not seem as green as the others. These plants were all purchased at the same time. Can you please tell me why? Thank you.
Heat, lack of water, lack of light and age can all cause leggy petunias like this. Make sure they are getting enough water and light and prune them back by about 1/3. This will force them to branch and will rejuvenate them if age is to blame.