I will be interested to hear how your experiment goes. Last night I planted out 23 dahlias, 12 of which were started in pots, the rest were sprouted tubers. Our average last frost date it tomorrow, and the 5 day forecast had lows no lower than 6 degrees, so I planted. Now the forecast may have changed for the weekend and it may get a but colder, down to 2 or 3 degrees. I hope they weather will improve, but if not I will be covering the plants up. It will be a long lasting lesson if I lose all the plants that I started from being too impatient! The problem was some of them I started way too early, one Akita dahlia already has flower buds on it!

I'm not sure if it would make any difference to frost hardiness whether the plant was started by tuber or cutting. The frost causes the cells in the leaves to swell and burst, therefore killing the folliage. I guess a tuber plant may come back after that, but the initial result of killing off the new growth, I would expect to be the same.

Even when I was planting I was thinking to myself that maybe I should wait a bit longer, but I was too anxious to get started on the season!

Janet

Hi Russ,

I read something about frost occuring when the actual temp drops below the dewpoint. I have 10 cuttings this year. They are still in 6 inch pots and are about 5 to 8 inches tall. I've been leaving them outside at night the past week. My nights are usually low to mid 40's. The other night it got as low as 38 degrees F. I have no foliage damage. They may wilt during the day if it's sunny and 70's but the cooler temps perk them back up. The only thing is, they seem to grow a little slower now. Before, I brought them inside at night and it seems they appreciated the household temps more during the night. I think when my night temps get up to the 50's they'll hopefully, start growing a little faster again.

Tracy

I agree that the colder temps are going to have an impact on growth. I am hoping that the real full sun they will get will compensate. Despite all my lighting attempts, I was never able to get anywhere near sufficient lumens indoors. Means I have another project to complete before December, namely to give myself adjustable lighting over where I start my cuttings.

My plants are going in tomorrow. My 68 into my formal Dahlia garden beds. Funny, as tomorrow or Wednesday are listed to be the coldest in a while...sigh, too bad I wasn't retired and able to do things when I wanted to rather than when I could get to them.

The extras are going to have to wait, unfortunately. I have to wait for the weed folks to put down the round-up, and then wait another week+ for it to do its thing before I roto-till.

Cheers,
Russ

Sorry to rain on your parade, Russ, but tomorrow ( zone 5 southern Ontario near Guelph ) the forecast is from 2C to 4C. I would wait until after that, or be prepared to cover them on Tuesday night. I know that I will be covering all of mine tomorrow night (Tuesday).

Jroot,

There's forecasts, and then there's forecasts...;-]

I'm 50' from a fairly large lake. It does all sorts of things to forecasts, especially considering it is currently 25C at 8:00pm.

My Dahlias will be within 5' of running water, which isn't going to get any colder than 5C no matter what the air temp goes to for an hour or two.

Anyway, I'm not putting anything out which I only have 1 of, so if it all fails misrably, I'll just do it again when I have time...;-]

Cheers,
Russ