As far as duration of flowering season is concerned, C. 'HJJ-HAZ01' CHLOE is one of the best clematis ever introduced. Yes, that is a bold statement. But after several years of growing it in the Pacific Northwest, the only other clematis that might come close to making the claim is another non-climber, C. 'Spark'. But we will leave C. 'Spark' for another day. This is CHLOE's turn to receive the spotlight.
C. 'HJJ-HAZ01' CHLOE was first introduced as C. 'Blue Cover', and if you are trying to find a thorough description of it in The International Register and Checklist Sixth Supplement, C. 'Blue Cover' is the place to start.
[Editor's note: I quote from the 6th Supplement of The Clematis Register and Checklist, "Originally registered as ‘Blue Cover’ by Ton Hannink & Tsang Mei Lan in 2014, and established as such in Clem. Int. 2015: 9, this cultivar was awarded US Plant Patent 27665 in February 2017 as ‘HJJ-HAZ01’. The latter therefore became its adopted epithet and
‘Blue Cover’ its synonym in geographical areas within USPP jurisdiction (ICNCP, 2016: Art. 11.3); elsewhere, ‘Blue Cover’ remains the accepted epithet."]
It is a selection of a cross made by Tsang Mei Lan (Hazel) of C. crispa (seed parent) and C. 'Rooguchi', with the C. integrifolia genetics from the pollen parent proving its dominance in the flower form and plant habit. In fact, other than perhaps the usual color, one sees precious little C. crispa in the look of C. 'HJJ-HAZ01' CHLOE at all. C. 'HJJ-HAZ01' CHLOE has a US plant patent, PP27665.
After reaching roughly 2/3 of a meter tall (24 inches more or less), C. 'HJJ-HAZ01' CHLOE starts blooming in mid-to-late May, and barring a mid-July chop, will continue for 16 weeks on average. As typical with C. integrifolia cultivars, the first flowers are largest, secondary blooms a bit smaller (but more prolific in numbers), and side shoots produce flowers smaller still. Just when you think you might want to cut it back to generate new growth and another wave of larger flowers, you may instead fertilize your plant (with a blossom booster or something labeled “rose & flower food”), and C. 'HJJ-HAZ01' CHLOE will produce new flower stems without being pruned.
C. 'HJJ-HAZ01' CHLOE - May 2023
C. 'HJJ-HAZ01' CHLOE - June 2023
The flowers generally have four sepals, as expected from its ancestry. Although listed as opening “moderate violet” and deepening to “strong violet” as it matures, there is room for variation here, probably having to do with light (full sun is best) and night temperatures. In summer heat, C. 'HJJ-HAZ01' CHLOE may appear more lavender/pink, and it has never been described by any of our visitors as blue. The flowers are of good substance and develop an out-facing pose when fully open, regardless of the nodding bells of its parents. One imagines C. 'HJJ-HAZ01' CHLOE would make an excellent cut flower.
Given its parentage, you will not be surprised to hear that this year, after we found dreaded vole activity around one crown of C. 'HJJ-HAZ01' CHLOE—it had to be lifted while we applied organic repellent to the soil (February)—the root mass recovered quickly in a pot and was replanted a scant two months later with flower buds forming (April). Thus, the rejuvenated C. 'HJJ-HAZ01' CHLOE started blooming at the same time as its two undisturbed bedmates, in May.
All three specimens were unplanned victims of the “Summer Pruning for Autumn Rebloom” class in early July (the instructor and yours truly had a miscommunication). Of all the non-climbers pruned that day, the three C. 'HJJ-HAZ01' CHLOE were the first to begin reblooming and were still popping small new flowers as of November 7, 2023.
C. 'HJJ-HAZ01' CHLOE - reblooming after July chop
C. 'HJJ-HAZ01' CHLOE - September 2023
Sadly, it is unable to leap tall buildings in a single bound, but otherwise Clematis 'HJJ-HAZ01' CHLOE is a superhero plant! Super flower form, super color, super hardiness and heartiness, and super duration of bloom.