GARDENING FACT SHEET:
Click to View Printable PDF file: “Growing Plants Under Pine Trees”
Dr. Tony Koski, professor at CSU and Extension Turfgrass Specialist explains why many plants won’t grow under Pine Trees…
MYTH: Plants won’t grow under pine trees because the pine needles make the soil too acidic.
FACT: Colorado soil has a very high pH. There could never be enough pine needles to lower the pH significantly. Fallen needles may SLOWLY make the soil more acidic, but more likely for the better since it neutralizes the pH. It takes decades to change the soil pH and will not decrease by more than .5 units!
So why is it so hard to grow plants under pine trees?
- Not enough light. Pine trees have dense canopies that let very little light in.
- Root competition. Colorado trees in general are shallow rooted and create significant competition for water and nutrients.
- Not enough water. Very little rain reaches inside the tree line because of the Pine tree’s dense canopy.
So what does grow under pine trees? The answer is any plants that will tolerate both dense shade and dry soils. Even then they will need supplemental watering.
Some suggestions to try:
- Kinnikinnick
- Brunnera
- Plumbago
- Avens (Geum)
- Mint
- Strawberry Coralbells
- Rose Campion
Click to View Printable PDF file: “Growing Plants Under Pine Trees”