HWT
I am doing a last few sowings using the HWT (hot water treatment). As explained and shown in previous postings, the HWT applied for Fabaceae species (and not only), causes fine fissures in the seed coats and allows for water imbibition, eliminating the need for the cold/moist stratification period.
Those unfamiliar with this method can follow the links to read more about it and to see more pictures:
Continuing the sowing: in hot water; Updates to the HWT; FAQ – hot water treatment
I am trying two new Astragalus species: Astragalus detritalis, debris milkvetch, a Colorodo native, with bright purple flowers and
Astragalus glycyphyllos, licorice milkvetch. You need to repeat the treatment 2-3+ times, especially for Astragalus species, but otherwise all is easy and some seeds may even start to germinate in the water.
And I’ll persevere, as long as I have seeds, with Oxytropis halleri. One plant flowered from my last attempt, but unfortunately vanished. It may be that our hot, humid summers are not to its liking, but it is worth trying it again. Oxytropis species are really hard to maintain in garden cultivation.
If you didn’t use the hot water method yet, give it a try. It is one of the easiest germination treatments to apply; for sure it beats sanding your fingers together with the seeds ;)
We cannot really generalize, but the majority species from Fabaceae family are easy germinators. The HWT is working well for: Astragalus, Baptisia, Hedysarum, Lupinus,
Oxytropis, Thermopsis. Considering how Lathyrus vernus self-sown seeds germinate in the garden, it would probably benefit as well. However, I didn’t manage to ‘break’ the Senna seeds with the HWT.
Species that would germinate at warm even without the HWT can also benefit from it to speed up the germination (Amphicarpaea).