Easy Grow
Hot Water
A few species are known to benefit from treatment with hot water,
which mimics the effect of a wildfire. Some seeds have dormancy mechanisms that require exposure to high temperatures, signaling
that a fire has recently occurred and there will be open soil available
for germination and growth of new seedlings. The prairie shrub,
New Jersey tea (Ceanothus americanus) is one that exhibits higher germination following exposure to hot water, followed by 30 days
of moist stratification. Place the seed to be treated in a bowl. Heat
water in a teakettle to boiling, then turn off the heat and allow the
water to cool for a minute or two. Pour the hot water over the seed
and allow it cool down to room temperature. Pour off the water, and
the seed can be seeded directly, or in the case of New Jersey Tea,
mixed with a damp inert material and moist stratified for 30 days
prior to seeding. Other growers have reported to have good results
using the hot water treatment with the genus Baptisia , followed by
placing the seed in the freezer for a short period, until ice crystals
begin to form on the wet seed (about one hour or less). One grower
uses this treatment three times in succession (hot water followed by
near-freezing) to obtain high rates of germination on this notoriously recalcitrant genus. Some seeds do not need water heated to boiling. Temperatures between 68 F and 86 F will be sufficiant.