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Contact Us

Physical Address:
1200 West Palouse River Drive

Hours:
Open everyday, dawn to dusk, free admission

Contact:
arboretum@uidaho.edu

Mailing Address:
875 Perimeter Drive MS 2281
Moscow, Idaho 83844-2281

Directions

Arboretum & Botanical Garden Bulletin Board

Blossom clusters on a hawthorn tree.
Crataegus laevigata ‘Paul’s Scarlet’ Hawthorn, May 24

Plant of the Month

‘Paul’s Scarlet’ Hawthorn
Crataegus laevigata ‘Paul’s Scarlet’
Location: Grid Q8 below the west side gravel road, among the European Lilacs.

There are lots of different Hawthorns, some native to most corners of the world. I think ‘Paul’s Scarlet’ might be the most ornamental of all of them. It has small, double bright scarlet flowers in clusters, and it generally blooms consistently every year in our climate.

Blossom clusters on a hawthorn tree.
Crataegus laevigata ‘Paul’s Scarlet’ Hawthorn, May 24

Hawthorns as a group are one of three groups of woody flowering plants that actually grow better here in Moscow than most anywhere else, with the other two being lilacs and crabapples. All of them need some cold period during the winter to set flower buds and none of them like hot, humid summers.

The tree in the Arboretum was planted in 1993, so could likely be considered mature sized by now. It is probably in the range of 25 feet tall and 12-15’ wide, so usually considered a small, ornamental tree. If it sets fruit, it is very sparse, small, hard red berries that are not usually significant. The disadvantages are it does have fairly vicious thorns, and it tends to grow lots of water sprouts or suckers that we try to prune out every year (and somehow manage to donate some blood to the thorns every year).

Associates and visitors aplenty visit the Facilities greenhouse for the annual plant sale.
Arboretum Associates Plant Sale, May 18

Monthly Projects

The big event for this month was the annual Arboretum Associates Plant Sale. After the old ice rink at the fairgrounds went away in 2023, we tried having the sale at the new ice rink last year. Results were pretty good, but the site did not work very well. This year we decided to downsize our offerings a little bit and held the sale outside the Facilities greenhouse where we grown the plants. That worked out great! We were able to do the entire set up and sale on Saturday morning, there was plenty of parking available, and although we did somewhat fewer sales, we had essentially no leftovers, and everyone was able to go home by 1 p.m.

We have been busy planting new things, over 500 ‘permanent woody plants and herbaceous perennials along with lots of colorful annuals in the annual bed and a new ‘Sunflower Strip’ beside the parking lot.

We also planted the new cold-hardy cacti collection down in the Xeriscape Garden, 20 different cacti, three trunk-forming Yuccas (including Joshua Trees) and a hardy agave.

Small bright yellow and small vivid purple flowers amid greenery.
Palouse Prairie pollinator strip, May 29

Upcoming Events

Arboretum Associates Annual Concert

  • 7 p.m. Monday, July 8 at the North End of the Upper Pond
  • Free Admission! Bring your lawn chairs and enjoy and acoustic concert put on by the Lionel Hampton School of Music and local community members.

When visiting the Arboretum, please remember that for your safety, the safety of others and for the protection of wildlife and plant collections, no pets are allowed. Ice on ponds is very unstable — stay off any ice.

Contact Us

Physical Address:
1200 West Palouse River Drive

Hours:
Open everyday, dawn to dusk, free admission

Contact:
arboretum@uidaho.edu

Mailing Address:
875 Perimeter Drive MS 2281
Moscow, Idaho 83844-2281

Directions