I planted my Red tip photinia last spring and it hasn't grown an inch. I mulched, watered accordingly, but no growth. Not dead, just isn't growing. I was told this was a fast growing plant.
If there's no spotting on the leaves (which would indicate one of several diseases,) it sounds like the roots just need to be encouraged a bit. Plants will grow roots before they grow leaves. Follow the cultural recommendations for photinia that follow, (make sure there's enough sun,) and try increasing the phosphorous addition. https://www.gardeningknowhow.com/ornamental/shrubs/photinia/growing-red-tip-photinia.htm
https://www.gardeningknowhow.com/ornamental/shrubs/photinia/red-tip-photinia-fertilizer.htm
I purchased 9 red tip photinias with multiple branches from the base. How do I prune into one trunk to look like a tree? Do I prune just after last frost? I live in north Texas and will be planting them this week.
I would wait till after last frost to prune.
To train the plants into a tree shape, choose a few string leader stems and remove all of the weaker and smaller stems from both the base and the small lateral branches from the sides of the leader branches up to where you want the canopy to start. This article will also outline how to do this in the "Shaping Tree-Form Shrubs" section:
http://www.clemson.edu/extension/hgic/plants/landscape/shrubs/hgic1053.html
Planted red tips today. Is it too early?
Frost has the potential to damage or kill any plant. If you are concerned about frost, there are things you can do to protect your newly planted red tips. The article below will give you many ideas on how to do so:
https://www.gardeningknowhow.com/plant-problems/environmental/frost-how-to-protect-your-plants.htm
For more information on growing red tips, please visit the following link:
https://www.gardeningknowhow.com/ornamental/shrubs/photinia/growing-red-tip-photinia.htm
When does the red tip photinia get new leaves? Our plants were newly planted last August and we had a real hard winter. Now we have no leaves on the plant but it still seems alive.
Since your red tip is otherwise healthy (or seemingly so) this is probably just a matter of having some patience. Delayed leaf-out is common after a hard winter. Plants have their own timetable of readiness when it comes to leafing out.
For more information on growing red tip photinia, please visit the following link:
https://www.gardeningknowhow.com/ornamental/shrubs/photinia/growing-red-tip-photinia.htm
I have red tip photinias that have grown too tall, 15-25 feet trees. Can I cut them back to the ground? They are 20 years old, planted as landscape shrubs by original owners, just too big now. Should I just pull them or are they salvageable?
Photinias can tolerate a hard pruning. You can cut back the entire shrub at one time to the height you desire. Just keep the shrub wider at the base than the top so that sunlight reaches the lower branches. Photinias can be cut down to about 6 inches above the ground. The following article will explain further:
https://www.gardeningknowhow.com/ornamental/shrubs/photinia/rejuvenating-red-tip-photinia.htm
For more photinia pruning tips please review the following article:
https://www.gardeningknowhow.com/ornamental/shrubs/photinia/pruning-photinia-shrubs.htm
My red tips have black spots.
Your photinia has leaf spot and this article will give you more information on leaf spot along with prevention/treatment tips:
https://www.gardeningknowhow.com/ornamental/shrubs/photinia/photinia-leaf-spot.htm
How do I take an 18-foot red tip and get it back to shrub size?
Here are some articles with great tips on how to prune your overgrown red tip:
https://www.gardeningknowhow.com/ornamental/shrubs/photinia/rejuvenating-red-tip-photinia.htm
https://www.gardeningknowhow.com/ornamental/shrubs/photinia/pruning-photinia-shrubs.htm