- Is there a problem with how the plants are arranged?
- Are there too many or too few plants?
- Are my plants too big or too small for my container?
- How do the colors/textures of the flowers and foliage work together?
- How do they work with the color of the container?
- Is my design just plain boring?
Once you think you may have identified the problem there are several ways to fix it.
Move 'em: The first and easiest thing to try is to simply move your plants around. Try grouping them differently or moving the plants front to the back. Don't be afraid to try out things you don't think will work. They might!
Subtract plants: If your container looks crowded try taking some plants out. Also, if you find that one of your plants clashes (in a bad way), take that one out. If you do take plants out of your design, either put them back in their plastic containers for use at a later time, or start a new container.
Add plants: Sometimes all it takes is a new plant or couple of plants to tie your design together. Maybe you need some filler plants - usually either small flowers or foliage plants that fill in and round out a container. Or maybe you need a plant that combines some of the colors of your other flowers or foliage
Get dramatic: If your container is boring, you may need to add some drama. Try adding a dramatic plant to be a focal point or get some contrasting flowers or foliage to add interest.
Size matters: I think the single most common container design mistake people make is that they don't vary the size of the plants. Large barrels are often filled with short petunias, which might be enhanced by adding some larger mounding plants, or something spiky or a climber.
Drip and drape: Having some plants falling gracefully over the side of your containers can enhance your overall design.
Try again tomorrow: In the words of Mark Knopfler, "sometimes your the windshield and sometimes you're the bug." You may just have to wait and try again when you have fresh perspective and renewed energy.