My favorite plant this week: Hebe 'Wiri Blush'

My favorite plant this week is another one that came through our recent heatwaves unscathed, Hebe 'Wiri Blush.'  This is not classified as a drought tolerant plant but it is considered heat tolerant.  Specifically, it's suited to AHS heat zones 7-12, which means it can tolerate conditions in which it's exposed to heat of 86F (30C) or greater for more than 210 days per year.*  When our temperature exceeded 104F (40C) last week, the plant didn't wilt, the flowers didn't shrivel, and the leaves didn't burn or drop.  The plant looked as good this week as it did at the end of April - better, perhaps, in that the heat seems to have prompted blooms that are normally associated with summer.

Hebe 'Wiri Blush' sits in my backyard border in front of one Phormium 'Dark Delight' and alongside 2 others

This is another plant I bought principally for its foliage.  The narrow leaves are a glossy green, edged in magenta.  The undersides of new leaves and the plant's stems have the same magenta color.  The plant is evergreen and grows 3-4 feet (90-120 cm) tall by 4 feet (120 cm) wide.  It seems to be a relatively fast grower - mine, planted in January 2013 from a 1 gallon pot, has already reached its mature size.  Its compact form is easily maintained with a little light pruning.

This foliage close-up shows the magenta undersides of the stems and the new growth

It grows in full to partial sun and normally blooms in summer through fall.  The flowers are a bright pink color.  They're also attractive to bees.

The flower spikes are about 3 inches long and hold up surprisingly well in cut flower arrangements

This New Zealand native requires good drainage and regular water.  Dry summer heat is said to shorten its life span.  As that's what it receives in my garden, we'll have to see how it does in the long haul but I'm very pleased with it thus far.  So pleased in fact, that I recently picked up another one for placement in my "red bed."  For those of you in cooler climates, this Hebe is said to handle low temperatures in the range of 0 to 10F (-18 to 12C).

Hebe 'Wiri Blush' is my contribution this week to the favorite plants meme hosted by Loree at danger garden.  Click here to see Loree's favorite of the week and to find links to other gardeners' selections.

*On a separate but related topic, looking at the heat tolerance of this plant led me to a closer examination of the American Horticultural Society's Heat Zone Map.  Unlike the USDA cold hardiness zones, I wasn't able to find a tool that linked heat zone directly to postal zip code.  I was left to deduce my zone based on my own possibly questionable reading of the AHS color-coded state map.  My reading of the 1997 map suggests that I reside in heat zone 6 or below, although average temperature data for downtown Los Angeles, which normally tracks our local temperature fairly closely, suggests that a zone 7 classification may be more accurate.  However, I have to wonder whether either estimate reflects the warming trend.  I'm also unsure whether this heat index helps me in assessing a plant's resilience in handling abrupt temperature fluctuations, such as those we've been experiencing.  Have you made use of the AHS heat tolerance index?  Do you find it of value in making plant selections?