Clumping bamboo in MA will not be the same as clumping bamboo in FL :-) Even in my pretty mild climate, clumping bamboo is an extremely manageable plant and I see no reason not assume a similar well-behaved habit in colder zones. From a regional bamboo specialty nursery: Overview of Clumping Bamboo Clumping bamboo are defined as having a non-invasive rhizome structure (known as pachymorph rhizome) which differs from the better known �and sometimes feared�running bamboo (leptomorph rhizome). Clumpers form a tight cluster of gently arching culms extending from a relatively small root mass. Each underground bud pushes upward forming culms, and do not become long running rhizomes. Instead, clumping bamboos grow outward in a circular formation at a modest pace of 2 to 12 inches per year. Canopy growth is also relatively slow, usually gaining a couple feet of height and width annually. Height range at maturity is between 10 and 20 feet for most species. There are some exceptions; tropical and subtropical species can reach 50 feet or more in the US, given hot, southern climates. We have a special affection for hardy clumping bamboos. We believe these plants will help overcome popular fears about bamboo, and pave the way to its acceptance as a significant addition to the landscape as well as its incorporation into our culture. Bamboo Garden is on the forefront of introducing new and exciting species of clumping bamboo into the United States and promoting their multitude of uses. Though many are new to cultivation, clumping bamboo are gaining recognition for their landscape value as low maintenance alternatives to the larger, more vigorous, running bamboos. Fargesia sp. �Rufa�, with plumes of feather-like foliage, provide a wonderful accent to the small urban garden. Larger species, such as F. robusta, create dense evergreen privacy screens to over 15 feet. The gracefully weeping culms of Borinda angustissima and F. sp. �Jiuzhaigou� support masses of tiny leaves with a delicate, airy texture. Outer culms can be topped to make the plant more compact and upright. New introduction, F. sp. �Scabrida�, has outstanding colors: purple culms outlined by rusty-red culm sheaths contrasting with dark green leaves. Some species, such as F. nitida, are among the most cold hardy bamboo, surviving temperatures as low as negative 20� Fahrenheit. Most thrive in a partial shade environment, but there is enough variety to find a suitable clumping bamboo for just about any need. Our selection have special significance and unique qualities for the home garden or commercial landscape. We hope the pages of our website offer a new perspective of the possibilities and wonderful variety among clumping bamboo. Here is a link that might be useful: Bamboo Gardens

Where I live, the outside temps can get down to 10F at times. I have an unheated greenhouse, so at least the plants are protected from wind. But the inside temperature at night is the same as outside. So I cover my tender plants with plastic film, and put a mist nozzle on top and let it run all night. This keeps the plants very close to freezing temperature, which seems to be good enough for them to survive. This works with outside temps down to the low 20's F. If you wanted to do it right, I guess you could turn your greenhouse benches into little hoophouses and rig the mist nozzles above them. If you don't have a greenhouse, you could cover the plants with plastic and rig a mist nozzle. But you have to make sure that the wind doesn't just blow the mist away. If wind is a problem, you could use a nozzle that makes a larger droplet size. But it will take more water. Or you could move all your plants into the house or crawl space a couple of times a year.

I can't really comment on overwintering herbs indoors because I've never done it but I would just say that rosemary, savory and thyme do not need particularly warm temps. Certainly no warmer than the plants on your 'cool' list. They will tolerate warmer temps but do not require them. Also, do you mean you are growing all these from seed? Rosemary will take a good while to get a usable plant from seed.

Hi Bill, I've read about people using an old 10 gallon aquarium and someone suggested using a reptile heating mat. I root hoya cuttings myself, but I do not use heating mat. I use a plastic storage, add a couple of inches of gravel, put some old 4" tiles on top of the gravel, add enough water so that the water is just below the tile, so the pot is not sitting in water. I cover the top with plastic, this creates a lot of humidity and keeps the water pretty warm inside since it is sealed. I place the container in my florida room in a very bright area, not direct sun, but warm room. I have also heard of people using aquarium light...this give off some slight heat to the plant that you are rooting. Here is a link to the Reptile heating mat... if you click on "expand description", it lists some features and it says "Horticulturists, the IntelliTemp is perfect as a seedling heat mat. Good luck! Here is a link that might be useful: Reptile Heating Mat