Rent Shop Volunteer Join

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?

Share

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

Thursday - May 20, 2010

From: Nampa, ID
Region: Rocky Mountain
Topic: Compost and Mulch, Transplants, Shade Tolerant, Shrubs
Title: Plant for part sun in Nampa Idaho
Answered by: Barbara Medford

QUESTION:

What could I plant in arid SW Idaho on the northwest side of my house along a border against the house? Most of the day this area is in shade, but at the hottest time of the day it gets a couple of hours of intense sun--can get to 100 degrees in mid-summer?

ANSWER:

This presents us with an interesting climatic problem. Canyon County is on the southwest border of Idaho with Oregon, and is in a USDA Hardiness Zone of 5b to 6a. That means that any plant there must be able to withstand pretty intense cold in the winter, with probably harsh winds on the northwest side of your house. Then, when summer comes along, a plant that is accustomed to part shade, which we consider to be 2 to 6 hours of sun a day, is suddenly confronted with blistering heat, including the heat reflected from the walls of the house.

We're thinking this should probably be some sort of shrub, if we can find one we think can take the two extremes of temperature it will be subjected to. Whatever we locate, you must be aware of that heat, and irrigate the plant accordingly. And don't spray water on the leaves during the sunny times of the day, as you will end up with scorched leaves. Water going into the soil early in the day, giving time for moisture to move through the limbs to the leaves and compensate for the transpiration from those leaves during the hot hours, will both cool the roots and support the rest of the plant. We will go to our Native Plant Database, select on Idaho, shrubs and part shade, and Combination Search. Then it will be necessary to read each page on the individual plants to see if it can adapt to the conditions you describe. We were surprised to find 8 good candidates for this spot, and checked the USDA Profile Map on each to determine that it grew natively either in Canyon County or nearby. Some, but not all, of these were described as tolerating sun (6 hours or more of sun), part shade (2 to 6 hours of sun) or shade (less than 2 hours of shade), which means they should be able to adapt to the space.

We would urge you to wait until Fall to plant these shrubs, because you don't want to put a small, newly transplanted bush into that sudden blast of heat every day. That is almost a guarantee for transplant shock. While you wait for Fall, we suggest you prepare the bed for the planned garden by working in a lot of compost and other organic material. This will build the bed up a little bit, greatly improve drainage so your frequent waterings won't leave the roots drowning, and will help the new little rootlets access the nutrients in the soil. When you actually put the plants in the ground, immediately mulch the area with 2 to 4 inches of a good shredded hardwood mulch. This will protect the roots from the intense temperatures at both ends of the scale that your bushes will be subjected to. Follow each link to the page on that plant to determine if the projected size, appearance and other considerations suit your purposes. 

From Our Native Plant Database: 

Amelanchier alnifolia (Saskatoon serviceberry)

Amorpha fruticosa (desert false indigo)

Arctostaphylos uva-ursi (kinnikinnick)

Ceanothus velutinus (snowbrush ceanothus)

Holodiscus discolor (oceanspray)

Lonicera involucrata (twinberry honeysuckle)

Mahonia aquifolium (hollyleaved barberry)

Mahonia repens (creeping barberry)

From our Native Plant Image Gallery:


Amelanchier alnifolia

Amorpha fruticosa

Arctostaphylos uva-ursi

Ceanothus velutinus

Holodiscus discolor

Lonicera involucrata

Mahonia aquifolium

Mahonia repens

 

 

 

 

More Shrubs Questions

Want to identify a shrub with golden to orangish berries in Minneapolis MN.
July 14, 2009 - Tall shrub or maybe tree with small berries golden to orangish color. The berries are not in large clumps but more twos and threes. Leaves are opposite each other, smooth edges and sort of elliptica...
view the full question and answer

Native sun shrubs and perennials to replace St. Augustine
June 06, 2008 - Hi, I live in Austin and I'm removing the St. Augustine from the southwest side of our house. This area gets intense sun all afternoon, and I'd really like to use a combination of native shrubs and...
view the full question and answer

Stopping erosion on bank of a Florida retention pond
July 21, 2015 - I live on a retention pond, which has had all vegetation killed by the lake doctor. As a result the bank has eroded so there is a drop off directly to the water rather than a sloping bank. What plan...
view the full question and answer

Perennials for flowerbed in Texas Panhandle
October 19, 2012 - I have a flowerbed in a partially shaded area and want some perennials. I live in the Texas Panhandle, soil is sandy, loamy. Hardiness zone is 6-B.
view the full question and answer

Thoughts on non-native Italian Cypress in Austin
January 01, 2014 - I would like to know your thoughts on growing Italian Cypress trees in Austin Texas? We are looking to create a privacy screen(and prepared to pay more for mature trees to cut down the wait to grow...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.