That's an excellent question! It's perfectly fine to mix different color temperatures. One landscape lighting company likened just using one temperature to imagining if Monet used only one color in his art: http://kenneyoutdoorsolutions.com/2011/10/led-cool-white-or-warm-white/

They enjoy playing with different color temperatures to add richness and dimension in a landscape lighting scheme. You can read more about exactly what temperatures they use for what effects--it's really artful! I think it would work well to mix them together.

Hope this helps!

Mixing color temps is a normal thing, however you have it backwards. You should be using the cooler temps (daylight 3600k +) for your plant material. The cool white color generally has a higher CRI, which makes the greens and the blues pop. In architecture however, it's a different story. The cold temps can make your home look spooky. Opt for the warmer 2700k color temps when considering anything architecture or outdoor living area. It is much more inviting.

As for fixtures- Dump the kichler idea. They are an A+ marketing company with a C+ product. Their LEDs are so loosely binned that you will get color hue variations of green, yellow and purple on the same board. Their new Radiax circuit boards yield a horrifically ugly beam pattern. You would be far better to invest in products from VOLTlighting.com Their MR16 LEDs are far better and their equipment is solid brass, unlike the plastic/ aluminum from Kichler. You will also be thousands of dollars ahead if your project is even small to medium sized. Good luck.

There's no concrete Answer when it comes to color temp but there's probably some general consensus. First of all When it comes to CRI (color rendering index) halogen light has close to a 100 rating. The sun is a 100 rating. So basically we see colors based on how the sun portrays them. When you alter those colors with artificial light it looks artificial. Warm white LEDs (2700-3000k) ALWAYS have a higher CRI than cool white LEDs and therefore look more natural. That said cool white LEDs have their place in designs, I use them for evergreens or pine trees and for down lights. I've attached a photo of a brick home I did in all cool white. These examples are the exception however, 95% of the time I light almost everything in 3000k warm white. Warm white should probably be your first choice for most of what you want to illuminate.

Twilight Designs Great info what you suggest for backyard patio which we use a lot at night. I bought 3000k but they say Bright White will it still be a warm color based on the K’s scale) Wondering if I should try and get 2700K? Is there that much noticeable difference between the to? thanks in advance for any help

What is best for downward post cap lighting on a deck? (Warm white or cool white)