It should work as long as the cold frame remains above greezing while the cuttings are getting well rooted. A bigger problem will probably be overheating. On sunny days cold frames can get really hot. A good investment would be a hingle that automatically opens at a certain temperature, otherwise you'll have to keep a daily eye on weather and open it yourself in the morning.

Which microphyllas did you get? I grew Wild Watermelon and San Carlos Festival this year from small cuttings. Wild Watermelon was a little slow, but San Carlos Festival grew quite fast and the plants bloomed all summer. Now is the real test, will they survive the winter?

I have San Carlos Festival and Hot Lips. I went ahead and planted them yesterday morning. I'm hoping this unseasonably warm weather will continue long enough for them to root in well. These seem to love the fall weather so maybe I'll get some new growth and can take some smaller cuttings to bring inside for the winter. We're fixing to get rain from Tammy so I decided to just take the plunge.

Shari

Good luck and I'd take cuttings. The cuttings should overwinter on a window sill if nowhere else is available. My San Carlos Festivals are now about 3 feet across and maybe a foot or so tall and blooming very well. A friend just brought a variegated microphylla back from Maine - just what I need, another one to try.

This s my third year with san carlos and it overwinters for me here in zone 6 So do my greggii's This is my first year for hot lips Greggii's really prefer dry well drained soil they hate to be wet! If you keep them dry they should survive the winter just fine! Sarah

I have had good luck with greggii's but have never grown any microphylla. My main concern is root establishment ahead of winter since I know these will overwinter here in a normal winter. They aren't in heavy soil so I have my fingers crossed. It can be a struggle to keep things inside overwinter. Thanks, Shari

Sarah, after several years has your San Carlos Festival become less lax? My plants are flat pancakes about 3 or 4 feet wide and a foot high. I'm hoping in the spring to be able to prune out the low branches that have grown way out over the lawn. Microphylla Wild Watermelon is just as bad, and the hybrid Raspberry Delight combines laxness with brittleness.

When it comes to overwintering the main thing I'm hoping for is more moderate rains, instead of the steady downpours of last year. The fact that you two had success last year gives me reason to hope, and for that I'm grateful.

Hi Ward, Mine is lax like alot of salvias, As a matter of fact I put a peony plant support on one and it's become part of the plant I can't remove it. I will take a picture now to show you. Sarah

Here are the pictures They aren't very good but it was raining plus the one area is a jungle of cypress vine. Sarah

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I was too lazy to build a cold frame. So instead I made a plunge bed/cold frame by heading to Target and buying the biggest translucent plastic storage box I could find (about 70 gal? 70 qt?--it's probably about 2' x 2' x 3' and cost me about $15.00) and dumping one 50-lb. bag of sand into the bottom. When the weather is freezing, I snap on the lid. When it's above freezing, I remove the lid. I water the sand, not the plants and let capillary action do the rest. Works like a charm, and I can always dismantle it easily.

I don't do any of that. I let nature take it's course. Sarah

The storage box idea is interesting. Haven't heard of that one before. Is yours in sun or shade?

Some notes on the posts:

Microphyllas are generally tougher than greggiis, so anyone who is doing well with the latter will do well with the first.

Wild Watermelon amd San Carlos Festival are the hardiest microphyllas. Hybrid greggii x microphyllas are also tougher. Some of these toughies are Cherry Chief, Raspberry Royale, and Maraschino.

I have large cold frames designed to make complete use of 4 x 8 plywood and 4 x 8 1/8" thick plexiglass sash, and use a Phonetics Sensaphone to help regulate temperatures. The footprint of the cold frames built this way vary from 8 x 16 to 8 x 20 and rise from 1 to 2 feet in front to 3 to 4 feet in the back. I make a window for the front using plexiglass. I run a perimeter around each of the panels of lapped 2 x 4s. The panels are connected together with lag bolts for easy assembly, disassembly, moving, and storage. The structure is set on a single or double layer of bricks to help keep the wood dry, and I fill in the bottom with 1 - 2 inches of fine crushed rock. Insulation is with 3/4 inch mylar urethane foam panels, also laid on the sashes for really cold weather. The single most important insulation for cold nights is either black plastic or a blue tarp covering the whole cold frame (or greenhouse), since most heat is lost through radiation, unless the structure is really leaky.

You can scale down the size of these cold frames and use greenhouse plastic instead of plexiglass.

Using my deluxe coldframes, I have gotten citrus trees and large stock plants of tropicals to survive power outages of 5 days with 8 degree, no wind, and 20 degree, 15 mph wind nights with no damage.

Thank you so much for your input! My longest planted greggii is a Cherry Chief and I did not know that it was a microphylla cross. I have alot of seeds that a Salvia forum poster shared with me earlier this year that I plan on sowing over winter and next spring. Some of those may benefit from one of your deluxe coldframes. My garage is the workshop and domain of the man of the house who resents all of my gardening stuff in there. Maybe I can get him to build me that coldframe once and for all.

Shari

Shari, I've planted out rooted cuttings of Hot Lips and Furman in late November without loss is spring - and my clay soil is very scary.

I forgot about that furman's red greggii That's also very hardy I have had it hear my second year and I'm a full zone north of all of you even Ward since he's in jersey pine barrens. Like Richard said I feel better now since he's the expert those micropyllas are very hardy as are the greggii x microphyllas I 've had that maraschino for a very long time and the only threat to it has been the very agressive jacob cline monarda didyma that is crowding it out. Sarah

Thanks Brenda, I feel much better! The San Carlos Festival is planted in my fastest draining bed so maybe I'll have luck with it also- I saw a bud yesterday so I'll see flowers soon. I hope to get enough growth on the leucantha to take a cutting to bring indoors.