In 2014, we determined our aim for the years’ century plant breeding mission was to see how giant a Zone 7b winter hardy agave we might create. We had seven agaves flower that 12 months, however solely two had the epic proportions we required.
A type of was a number of Agave x protamericana from a Yucca Do assortment in Northern Mexico. By the point of flowering at 15 years of age, it had reached 5′ tall x 9′ extensive.
Agave x protamericana and Agave americana are the 2 largest blue-foliaged agaves, however solely Agave x protamericana is winter hardy for us, right here in Zone 7b, because it additionally has some historic genes from the marginally hardier Agave asperrima, which provides barely to its winter hardiness. You’ll be able to distinguish the 2 crops by feeling the again of the leaves. Agave americana has easy leaf backs, whereas Agave x protamericana has sandpapery leaf backs. The biggest dimension listed for Agave americana in Howard Gentry’s Agaves of Continental North America, is 6′ tall x 12′ extensive.
On the similar time we had a blind flower shoot on our big Agave x pseudoferox ‘Bellville’. Agave x pseudoferox is one other historic Mexican hybrid in want of a DNA workup. We expect its most likely a hybrid of Agave x protamericana with Agave salmiana var. ferox and presumably Agave gentryi). Commercially, it’s often known as Agave salmiana var. ferox, which is analogous in look, however with completely no winter hardiness.
Previous to full flowering at 15 years of age, our big specimen of Agave x pseudoferox ‘Bellville’ had reached a mature dimension of 4′ tall x 8′ extensive. We had been capable of make the cross previous to it absolutely flowering, through the use of one thing we talked about above that we name “blind shoots” or boners.
Being monocarpic crops, the rosettes of most agave species die after flowering, however facet shoots are an fascinating phenomenon we see on all of our Agave x pseudoferox cultivars and hybrids. These “blind shoots” emerge from underground stolons as an alternative of from a rosette. They’re much shorter than regular flowering shoots which emerge from the rosettes (2′ tall vs. 20′ tall), and so they haven’t any influence on the life expectancy of any of the rosettes.
Within the case of Agave ‘Bellville’, our plant started producing blind shoots 5 years previous to the clump producing a full dimension, rosette-based flower stalk. The great thing about blind shoots is that they breed and go alongside traits of the guardian with out the necessity for a tall ladder.
We gave our hybrids the seed pressure cultivar title, Agave ‘Bluebell Giants’. From these, we chosen 23 clones, which had been planted within the trial fields in 2016. Of these, solely 4 survived our subsequent trials for winter hardiness.
Our greatest and most winter hardy seedling from the cross pictured beneath is now 6 years outdated within the backyard. We’ve given this the title Agave ‘Supersize’. It has achieved a dimension of 6′ tall x 8′ extensive in that point. To place this in perspective, it’s bigger at 6 years outdated than each dad and mom had been at 15 years outdated. If Agave ‘Supersize’ waits till age 15 to flower, it might simply attain extra huge proportions that any Zone 7b winter hardy agave in existence.
