En Español

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?


Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

rate this answer
Not Yet Rated

Monday - May 09, 2011

From: San Jose, CA
Region: California
Topic: Trees
Title: Trees for small spaces from San Jose CA
Answered by: Barbara Medford


What tree can you plant in a corner of a yard 3ft from a fence? What is the best shade tree for a small yard with a pool?


Mr. Smarty Plants hates to disappoint gardeners, but some requests are for plants that really won't work in the described situation. There are several trees that could be planted in the corner of a fence that would do well in your area. The questions you will have to ask yourself are: (1) can the roots go under the fence and are they going to interfere with any paving or landscaping on either side, yours or the neighbor's? and (2) ditto for the top of the tree. Depending on how tall the tree and how tall the fence, the crown or leafy top may already be at the top of the fence or soon get there. Then what? Is the tree going to shade something in your neighbor's yard that he doesn't want shaded? Or drop leaves, flowers, seeds, etc. on both sides of the fence? In terms of shade in a small yard with a pool, we don't want to be flip, but have you considered a large umbrella?

Roots of trees generally extend at least as far out as the shadow of the canopy of the tree. This area is referred to as the Protected Root Zone (PRZ). While a tree and its rootball would probably initially fit into the 3 ft. space in the fence corner, the roots will quickly grow beyond it.  Additionally, the roots of the tree have the potential to damage/crack any concrete they encounter as they grow trying to reach water and oxygen.

We are frequently asked for "taproot trees," on the assumption that a root that grows straight down will not interfere with concrete walks, driveways, sidewalks and foundations. Alas, some trees do begin with a taproot but there are few trees with a true taproot; as time goes by roots will spread from that center root, both in search of water and nutrients and also as a base to stabilize the tree in the ground. A tree tall enough, and with comparable width to provide shade for your pool area, is going to have roots extending far beyond the initial area, if either the tree or the pool survive the planting there. A tree big enough to cast shade, say, 20 ft. tall, will usually have about the same spread-20' wide. The roots beneath that tree will normally spread out from two to three times farther than the crown.

There are shrubs that might fit into that corner space and or not interfere with your pool, but they will not get big enough to cast appreciable shade. What they will cast is leaves, twigs, bugs, fruit and seeds into that pool, that will need cleaning up.

We are going to list a few shrubs that are native to the Santa Clara Co. area in central coastal California, USDA Hardiness Zone 9. Shrubs have less invasive roots than trees, can maintain a space in the landscape; some are evergreen, but they won't get big enough for shade. We will find suggestions for you by going to our Recommended Species section, clicking on Northern California on the map, and searching on the sidebar at the right-hand side of the page on "shrub" for Habit. Follow each plant link to our webpage on that plant to find out more about size, growth habits, care, sun requirements, etc. You can use the same technique to make other choices or select trees, herbaceous blooming plants and so forth.

Shrubs for Central California:

Amelanchier alnifolia (Saskatoon serviceberry) - deciduous, 3-18 ft. tall, blooms white April to June, can grow in sun, part sun or shade

Arctostaphylos uva-ursi (Kinnikinnick) - trailing, 1-3 ft., evergreen, blooms white, pink March to June, sun, part shade or shade

Ceanothus velutinus (Snowbrush) - evergreen, 6-12 ft., sun, part shade or shade,  blooms white April to August

Garrya elliptica (Wavyleaf silktassel)- evergreen, 10 ft., sun or part shade, blooms white December to February. Pictures from Google.

From our Native Plant Image Gallery:

Amelanchier alnifolia

Arctostaphylos uva-ursi

Ceanothus velutinus




More Trees Questions

Aging Arizona Ash in Austin
May 04, 2014 - Mr. Smarty Plants! I live in South Austin and just bought a house with a large, 30-40 year old Arizona Ash in the backyard. When I moved in, most of the lower branches were bare and dead and so I had ...
view the full question and answer

Encouraging branch growth of live oak trees in Austin
February 10, 2009 - I recently had an elm tree cut down that was crowding out 2 live oak trees in my front yard. The oaks have no branches on the sides that were next to the elm. The elm stump is still there. I need to ...
view the full question and answer

Pecan leaves falling off the trees in Austin, TX.
August 08, 2012 - Why are the pecan tree leaves turning black, sappy and falling off the trees, in great quantities? This has happened since the recent rains, all through the Allandale area.
view the full question and answer

Non-native Royal Empress tree with only green leaves from Chambersburg PA
July 12, 2013 - I have 3 Royal Empress trees in my yard that are between 2-4 yrs old and have never been any color other then big Green leaves. Do you know when they will turn Purple?
view the full question and answer

Inquiry about the Arizona Cypress trees in the Family Garden
March 20, 2015 - Dear Mr. Smarty Plants, I recently visited The Wildflower Center and enjoyed seeing several features that were new since my last visit two years ago. In the Family Garden areas I saw several beautifu...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.
© 2016 Lady Bird Johnson Wildflower Center