Serissas and cold; the experiences of two friends.

In an earlier post, "Serissas: Finding the limits on cold," I mentioned two other men who are experimenting with the cold-hardiness of serissa.

Carl Rosner lives in New Jersey, on the border between USDA Zones 6 and 7. This means that in a "typical" winter, he will see temperatures in the single digits F (roughly -12° to -17° C) from time to time, with the occasional dip to -5° F (-20.5° C.) Carl overwinters his serissas outdoors. Yes, outdoors.

Carl's custom is to bury a serissa up to the first branches in the garden. (I believe he picks spots sheltered from wind.) Then he covers the rest of the plant -- the whole thing -- with mulch, and leaves it until spring. His serissas not only survive, they thrive! They reward him with a profusion of blooms every spring (I've seen pictures,) and seedlings from time to time.

Bill Swain lives in western Massachusetts state, in the milder half of USDA climate Zone 5: in a "typical" winter, Bill can expect the temperature to get down to -15° F (-26° C) at least once.

In 2010, Bill took three serissas (ones he could afford to lose,) and planted them outside in sheltered spots. Two were the species (Serissa foetida,) and one was the 'Snow Rose' cultivar. When winter came, he mulched them heavily and left them alone. I, frankly, did not expect them to survive, and I think Bill really didn't either.

Two of Bill's in-ground serissas made it thru! Those two were the species serissas; the 'Snow Rose' perished.  Bill reported that the foliage and all the fine twigs died during the winter; but the thicker stems started putting out new growth in mid-spring. To say I was astounded is an understatement!

I'm next. I told Bill that if his serissas made it thru the winter somehow, I would repeat his experiment in 2012 (or maybe 2013; I want them pencil-thick.) My climate is a bit colder than western Massachusetts, so we shall see. Stay tuned!