Surface Tree Roots & Bougainvillea Hasn’t Bloomed

Question:

I’d like to plant a couple of tall, deciduous trees to shade a southwest porch as well as a second-story window. My first choice is the Festival Sweet Gum (Liquidambar) for its leaf shape and fall color. The Sunset Western Garden Book mentions that the tree puts out surface roots. I plan to dig a hole four to five feet deep and as wide. Will this alleviate the root problem? It would be an expensive mistake if the roots tore up my porch.

Answer:

  • Unfortunately, increasing the size of the planting hole isn’t going to solve the surface root problem.
  • Liquidambar roots more than likely will come to the surface but not anytime soon. It will occur sooner with surface watering and you prolong it by using a deep root irrigator to water during the summer months. So, I wouldn't risk planting a Liquidambar tree and damaging the porch.
  • Instead, I suggest you consider planting a Crape Myrtle or Flowering Pear, not the Evergreen Pear. Typical these trees do not have a columnar shape, as they’re more ‘Vase’ habit. With a little pruning, you can straighten out the sides and have them do exactly what you want.
  • Crape Myrtles depending on the variety bloom July through September while the Flowering Pears bloom in February/March. They both have marvelous fall color, but don't have a maple-like leaf.
  • Another option is the deciduous saucer magnolias.  They have elegant flowers in the spring but no fall color. Magnolia soulangiana or soulangiana ‘Jurmag1 are two varieties available from Monrovia to consider. For more information go online to monrovia.com.   The available is limited at this time of the year. February through April is when I’d check with your favorite garden center for availably. 

Question:

We bought a beautiful pink Bougainvillea last year but It hasn’t bloomed this year.  What’s going on?

Answer:

  •  Your Bougainvilleas should be in bloom by now. Bougainvilleas need lots of light, at least six hours, in order to bloom.
  • They're much like a Poinsettia. The color portion of the plant is a modified leaf called a bract. The bracts need lots of bright light in order to turn color. The actual flower is the structure in the center of the bracts.
  • With Bougainvillea, the flower is the white structure that looks like a cross or circular disk. It's referred to as an incomplete flower as it has no sepals or petals. The western exposure should be perfect. However, if it's planted under an eve or is shaded by a building or large tree. It might not be getting enough.  So, I can't tell you for sure what the cause is but the problem is with the light.