Planting Under Redwood Trees & Controlling Blackberries

Question:

My husband removed the Ivy growing under a large Redwood tree and planted Azaleas. Unfortunately, he has had to replant them several times as they keep on dying. The leaves on the plant's wilt, turn brown and then die. He dug small holes with a pickaxe because of the heavy clay soil and the tree roots. The area is watered every other day by automatic sprinklers. Do Redwood trees affect the soil so that Azaleas can't grow? 

Answer:

Redwood trees do not produce any type of natural toxins that would affect the growth of Azaleas or any other plants.
  • This also applies to every other conifer and many shade trees.
  • With automatic irrigation systems, mature trees tend to be surface rooted and Redwoods are typically shallow rooted anyway. Their extensive root system makes planting and growing plants under them difficult as they compete for water and nutrients.
    • Ivy thrives while more desirable plants suffer because Ivy can root everywhere it grows. This is not the case with other ornamental plants who roots are located in a central root ball. Also, this makes digging holes for new plants difficult but not impossible.
  • Azaleas don't thrive in heavy clay soil without the planting holes being amended. I'd plant away from the tree trunk to avoid the largest tree roots. The planting holes should be twice as wide or wider than the container and six inches deeper. I'd replace the native soil with an Azalea or Acid Planting Mix or mix it at a 50/50 ratio with the native soil.
    • Before planting be sure the plants are wet and slice through the root mass to break the circular pattern so they root into the backfill. The top of the root ball should be above the soil surface, so they don’t sink and get buried.
  • This is all easier said than done. I think an easier solution would be to plant the azaleas in containers and sink them part way in the ground and then cover the balance of the area with some type of non-vegetative ground cover. My biggest concern now is whether or not the irrigation system will be able to water the containers. If not, maybe a drip system will work and at last resort hand watering.

Question:

 My tool shed has a large blackberry vine growing between it and the fence. I can't keep the runners from spreading because of the narrow space. Also, I can't dig up or get to the mother plant. Is there something I can use or do to rid myself of this problem?             

Answer:

  •  I’d spray the foliage with Brush-B-Gon or similar herbicide. However, I’d concerned about the desirable plants growing on the other side of the fence as they could suffer some damage. I’d limit my spray to the foliage only by using ‘a ready to use’ product, RTU or a tank sprayer. I’d make repeat applications as necessary.
  • This solution will not eradicate the problem as you can’t get to the mother plant. A more successful option would be to access the fence from your neighbor side. With his permission, you could then pen up the section of the fence and spray the mother plant.  Now, it’s a war attrition which you should win.