oh that would be great to see any of them seed but that won't happen for obvious reasons I don't believe my largest sunflower will even flower but it is soooo close to flowering it's almost a coin toss because after a few days into october anything could happen with frost ,even one or two good hard frosts is more likely than not . According to watching the rest of them flower , I would guess I am about 5 to 9 days away from my largest one flowering . I've been doing a photo journal and as of this morning it is now slightly more than 11 feet 7 inches to the flower ...it will get over 12 feet. No frost warnings in the near or even distant forecast (it could change )and in the next 5 days it will be as low as 35F with wind chill and as high as 75F . So as you can see my sunflowers are living on the edge a few of them look a little beat up but even they are producing a larger and larger flower head with each passing day . Thankyou for the heads up on the signs of weather tolerance and damage .

I'm frequently surprised by growers who think that just because a plant will tolerate a particular condition, somehow that condition must have no negative effects on a plant; or that the way they treat their plants is an appropriate model for others. The fact is, that most plants that thrive at higher temperatures cannot carry on photosynthesis effectively when mean temperatures are much lower than 65*. And at temperatures lower than about 60*, N becomes very difficult for the plant to assimilate. Essentially the low temperatures some suggest are a-ok, force the plant to operate on 'battery power' - which would be the plant dipping into its (stored) energy reserves to fuel its day to day activities and keep its systems orderly. That means that at low mean temperatures, the plant is back-sliding - losing potential. (The collective) YOU may not be able to actually see the ill effects, but that is no reason to assume they are not in play. A plant that is kept warmer will still be able to carry on photosynthesis, so if all else is equal, they will develop faster, grow larger, and bloom sooner. Where plants are concerned, lost potential isn't readily seen, but it is a chronic issue for those who don't fully understand how to systematically eliminate or at least ameliorate those conditions that have the potential to limit our plants. Keep in mind that lost potential is lost forever. It can never be regained, even if the plant was restored to perfect health and grown under perfect conditions for as long as it remains viable. Clusty - you'd do well to keep your plants at mean temps higher than 60-65*, so I think you made the right decision. Al

Marla i had the same thing happen to me. put them plants out in your greenhouse when their is some sun and take them back in at nightif a freeze is possible.if you want to leave them out all night put 2 electric heaters in the greenhouse before night and check temp around 11 pm to make sure your temp is at least 35 degrees- hopefully around 40 they are not cheap but they will save your plants also cover with loose sheets of plastic at nights and remove in morning once it warms up. in your area i would think you have about 2-3 weeks and then you should be in the clear at night with just the loose plastic, but have heaters ready!Mark

Penneye, I think I would just try to cover them up the best I could if the 20s are just for a night or two. Digging up the plants would disrupt their growth and they might be set back enough that they wouldn't survive or might survive but not grow well. I'd cover them up with buckets/leaves and heap more leaves on top of the ground around the buckets. If you have any unused blankets or sleeping bags, I'd be tempted to throw those over the buckets and leaves for an extra layer of protection. Just be sure to uncover everything in the morning before the sun rises too high in the sky so your plants won't bake. Also, before you cover the plants, make sure the soil is moist because dry roots suffer freeze damage more quickly than moist roots. Good luck, Dawn