Since I have phlox volunteers, extremely small ones have to be able to survive the winters.

A bigger problem is going to be drying out. I honestly wouldn't worry about winter.

z7 long island.. has no clue what a bad winter is ... lol ...

they do just fine here in z5 MI ... where winter is winter ... not some news event ..

dont worry about them ...

there is NOTHING better you can do .. other than put them in mother earth ...

any other ideas ... are contrary to mother earth.. and will only complicate.. how easy it is ...

part of your problem.. is thinking about them as babies ... they arent.. they are zone appropriate plants.. that have been coping in mother earth for millions of years ... so let them ...

good luck

ken

I also have found small phlox to be quite vigorous and have good survival.

Thanks so much!
I was worried that maybe the roots/plant/whatever hadn't had time to develop enough to make it through. As this is the first house I've been able to garden at I'm still learning.

As a side question, do most zone hardy perennials have the ability to make it through a winter even if they don't quite seem sturdy? I have a few other plants that are just breaking ground (don't have anything invested in them, had the seeds and threw them in early August) I would think that there needs to be some level of establishment for a plant to make it? no?

The answer is 'it depends'. I sowed seeds just six weeks ago of coreopsis lanceolata and Engelmannia peristenia. I have transplanted them into dixie cups and will be planting them into the ground in a couple of weeks.

The coreopsis is nearly half the size of a flowering size plant already (to my surprise), the engelmann's is a much smaller rosette. Both plants will form a basal rosette for the winter and should be just fine. Both plants are hardy to zone 3 or 4.

If however, I planted lantana horrida seeds, which is fairly hardy here, at the same time, it would be perhaps 3 leaves by now..and would almost certainly perish.

It is possible that you might have problems with plants rated to zone 7. However, since most of the common perennials are hardy to at least zone 5, your winter temperatures aren't something they are going to worry about.

What kind of rootballs do they have? I don't use the top/visible growth as my guide for seedlings, but use how extensive the young root systems are.

I'm in zone 5 and perennials hardy to my zone or below, sown in July survive over winter for me very well. They are often only a couple of inches tall by the first frost.

Hope your seedling do well next year !