2020 Spring Plant Updates

What's Growin' On?

Since COVID-19 decided to crash our Spring Open House events, here's a brief write up of what's going on in the fields at UC Davis and South Coast REC. We started deficit irrigation treatments at both sites in early April this year. Hopefully we will be able to open the fields during the summer and fall, conditions permitting. A list of all plants being evaluated this year is here: 2020 Trials list  

ROSES

This February we pruned all roses at both sites. The groundcover roses, Apricot Drift^®, Peach Drift^®, and Flower Carpet^® Pink Supreme, were sheared back with electric hedge shears. Using loppers, Chi™ and Lemon Fizz Kolorscape^® were reduced in size by 2/3, while Coral Knock Out^® was cut back to 1’. For all roses any dead or diseased material was removed during pruning. At UC Davis, Lemon Fizz Kolorscape^® was very early to bloom, followed closely by Coral Knock Out^®, then Apricot Drift^®, Peach Drift^® and Chi™.  Pink Supreme Flower Carpet^® is loaded with buds. At South Coast REC all the roses opened in April.

Roses at South Coast REC at the end of January 2020 before pruning.

The apricot colored buds of Apricot Drift^® take on an increasingly pinkish hue as they open with old blooms fading to a light pink. The blooms are reminiscent of old garden roses; perhaps a case of Honey I’ve Shrunk the ‘Abraham Darby', if you will.  

Chi™ produces clusters of velvety red semi-double blooms with bright yellow stamens.

Coral Knock Out^® flowers fade as they age, creating a multi-shaded panoply of pinks and salmons redolent of the gradients found on paint swatches at home improvement stores.

The colors on Coral Knock Out^® really "pop" during twilight.

The buds on the aptly named Peach Drift^® are yellow with blushes of dark pink, opening to reveal light pink flowers with orange or yellow coloration at the base of the petals. As the flowers age, some will take on deeper yellow or cerise coloration before fading to a warm white.

The blooms of Lemon Fizz Kolorscape^® start bright and fade to pastel yellow over time. (Photo: Karrie Reid)

The vivid blooms of Flower Carpet^® Pink Supreme are just opening up at UC Davis!

SHRUBS

We are evaluating eight taxa that could be classed as shrubs this year. At both sites Buddleia Pugster Blue^® was pruned back by 1/3 in late winter to remove spent flowers. We are trialing two Rhaphiolepis cultivars: a smaller cultivar, R. ‘Parhap’ Oriental Pearl (2-3’ H x 2.5-3.5’ W), and a larger cultivar, R. indica ‘sPg-3-003’ RedBird™ (4-6’ H x 4-6’ W).  Cotinus coggygria Winecraft Black^® broke dormancy roughly a month ago and has pushed out a crop of leaves colored either Pinot Noir ruby or dark Syrah purple depending upon the lighting conditions. At South Coast REC, Hamelia Sierra Red™ has pushed out bright green new growth after going dormant over the winter. Vitex Galatctic Pink^® has transformed from bare stems at the beginning of the month to a fully covered shrub with the same alacrity of someone preparing in the morning for their first Zoom meeting. Little Ragu^® sweet bay and xPyrocomeles Juke Box^® are evergreen and have continued to grow maintenance free since they were planted in 2018.

Currently Rhaphiolepis Oriental Pearl is covered in crisp white flowers with strawberry red centers. Rhaphiolepis Redbird™ is grabbing our attention with brick red new growth.

xPyrocomeles Juke Box^® has played along with all sorts of conditions over the past 18 months while maintaining it’s neat, tidy habit since it was planted in Fall 2018. Juke Box^® is the result of an intergeneric hybrid between Chaenomeles and Pyracantha.

The richly colored new foliage on Hamelia Sierra Red™. (Photo: Darren Haver)

PERENNIALS

Hypericum Sunny Boulevard^® has pushed out new growth at both sites after being pruned in March. After recently pruning out a few old flower stalks and dead leaves, we can enjoy the new flower spikes emerging from Hesperaloe Sandia Glow^®. Depending on your location, Tecomaria ‘Red Riot’ may be deciduous and die to the ground in winter (UC Davis) or evergreen (South Coast REC). At UC Davis, 'Red Riot' flowered profusely from mid-October through November in 2019, died to the ground in winter, and began to emerge in late March this year. At South Coast REC, 'Red Riot' continued to bloom throughout the winter and remained evergreen. To maintain a uniform appearance, any long sprawling stems were headed back to roughly 2’ at the nearest pair of buds. This was done before measurements were collected in April.

The watermelon red spikes of Sandia Glow^® false yucca are attractive even if the blooms aren't open. As the new spikes emerge they are reminiscent of long slender spears of asparagus, albeit red.

Flowers on ‘Riot Red’ at South Coast REC in January 2020.

GROUND COVERS

We are evaluating several groundcovers: two ground hugging lawn alternatives: Kurapia ‘Pink’ and  Ruschia ‘Nana’, and two taller spreaders from down under: Eremophilia glabra ‘EREM1’ Grey Horizon™ and Rhagodia spinescens ‘SAB01’ Aussie Flatbush™. Ruschia ‘Nana’ is a succulent with a low habit that tightly hugs the ground with occasional pale pink blossoms.  

The Princess and the Pea effect: due to the "chunky" bark we mulch with in Davis, some of the Ruschia 'Nana' appear bumpy. 

Eremophilia Grey Horizon™ has bluish-gray foliage which has been adorned since late winter/early spring with orange juice colored flowers, occasionally with a ruby blush, arranged around the stems in a whorled pattern.

The arrow shaped leaves of Aussie Flatbush™ emerge a gray-green with a whitish hue and age to a crème-de-menthe green. In the waning light of a sunset, the gray coloration creates an ethereal halo.

The flowers on Kurapia^® 'Pink'

50% SHADE

This is the first year that plants will be evaluated in 50% shade conditions at South Coast REC. Hydrangea quercifolia Tara™ and H. paniculata White Wedding^® were deadheaded in March as they broke dormancy. At UC Davis White Wedding^® leafed out first, followed up by Tara™. Lomandra 'Katrinus Deluxe’ has a blousier form and thicker, wider leaves than previously evaluated cultivars. Ilex Sky Box^® is a columnar evergreen holly with dainty round leaves being evaluated at South Coast REC. Azalea Autumn Bonfire™ was trialed previously in at UC Davis and researchers are excited to evaluate its performance on reclaimed irrigation water at South Coast REC. Autumn Bonfire™ finished it's annual spring flush of bloom last month.

White Wedding^® hydrangea has bright green ovate leaves.

The foliage on Tara™ is a deeper green, with deeply lobed palmate leaves and the rich surface texture typical of H. quercifolia cultivars. They're also pushing out buds!

The flower spikes on Lomandra 'Katrinus Deluxe' are held aloft of the plants.

All Photos by JA Sisneroz unless otherwise noted.