I have verbena homestead flowers. The foliage is pretty and green and growing but it doesn't produce flowers. What's wrong with this plant?
It's likely the fertilizer. If fertilizer has too much nitrogen, it will encourage more foliage growth as opposed to flowering, which needs more phosphorus. Use a "bloom booster" fertilizer or add some bone meal to the soil to help add some phosphorus.
Cannot get verbena seeds to germinate. Have tried for several years but will only get one or two out of 25 seeds.
Verbena has a very hard seed coat that must be softened beforehand in order for germination to occur. I would recommend soaking the seeds in water prior to planting them. This article will help with that: https://www.gardeningknowhow.com/garden-how-to/seeds/soaking-seeds.htm
I purchased a beautiful verbena basket in April that was thriving until we left for 5 days for vacation. It got too dry and looks stressed, burnt, etc. I trimmed it back, watered and will fertilize tomorrow. Is there anything else I should do? It's in direct sun still.
Don't fertilize. Fertilizer should not be put onto stressed, dry, or sick plants. Wait until the plant has started some new growth.
Make sure the soil has been well hydrated; put the whole plant in a bucket of water and let it soak for 15 or 30 minutes.
It should be fine. Here's an article on watering outdoor container plants: https://www.gardeningknowhow.com/special/containers/container-plant-watering.htm
In the future, if you take some steps to protect your plants when you go on vacation, they'll get along much better. Most important would be to move them to a more shaded area. Here are some other ideas. This article deals with indoor plants, but many of the principles are the same: https://www.gardeningknowhow.com/houseplants/hpgen/while-youre-away-vacation-care-for-houseplants.htm
My purple and white verbena is growing roots under flowers. Does this mean I can trim that and replant? Is this a way I can propagate the flower?
It sounds like you have "Homestead Verbena". Verbena is not propagated by its roots but by cuttings from the plant itself, which can be rooted in water or potting soil. For more information on propagating from plant cuttings, please visit the following link:
https://www.gardeningknowhow.com/garden-how-to/projects/rooting-plant-cuttings.htm
Why are my verbena leaf edges white, looking bleached out? The leaves are drying where they are white. Did I burn then while watering with fertilizer? I have several verbena plants in pots, full sun, on my deck. They have been in the pots 3 weeks. A couple of the plants have shriveled, also.
Yes, your plants may have been burned from the fertilizer. You can try flushing the plants with water to remove excess fertilizer.
Here are a few links that may be of help.
https://www.gardeningknowhow.com/ornamental/flowers/verbena/growing-verbena-plants.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/what-is-fertilizer-burn.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/fertilizer-burn-in-gardens.htm
How do I know if the verbena plant I have is annual or perennial? I am looking for a ground cover that will spread and decrease weed growth on a bank along the road in my front yard, and also one around my back porch that gets morning to mid afternoon sun. This also will border my fish pond.
This article will describe perennial verbena and will help you identify if it the kind you have:
http://homeguides.sfgate.com/characteristics-perennial-verbena-38564.html
Do I need to trim all the heads of verbena after they have flowered or do they flower on same heads?
Yes, you can trim back the spent flowers and the plant to encourage longer and more bloom time.
https://www.gardeningknowhow.com/ornamental/flowers/verbena/growing-verbena-plants.htm