I'll take a jab at this one. I was waiting to see if others might have better news, but since nobody has responded I'll tell you of my experience.

I am in zone 5 which is milder than yours. When my newly planted lilies did that in fall, they never regrew the following spring. I think the new growth used up the nutrients in the bulbs and the bulbs had not had time to be replenished before frost and deep freeze. Therefore, no more bulb to grow in spring.

Someone has posted here previously that his would regrow, but I am quite sure he lived in a milder climate or at least where there was a warmer pocket in his garden. I have not tried cutting them off or mulching. It maybe worth it.

On the other hand, I am contradicting myself here: how come those Tiger lily bulbils that lie on the ground with no protectition make it through deep winter without any problem? Thinking out loud here, ya know. ??!??
Good luck.

I would just trim down when the first frost or snow hits then mulch to protect them ok? Just my two cents.

I have never had it happen but I would cut them back so they waste no energy. If they didn't bloom they surely would spend their time reproducing and making a big bulb next summer. I don't think you would loose them. It is odd that a lily would do this unless you got them cheaply from someone who was still selling last years stored bulbs. That is why we keep saying to buy them from a reliable source and pay a bit more. Better to have less and have healthy.

HI! I had a few lillies do that to me last year. The asiatics came back and did ok but were not full size, some of the orientals came back but were tiny (like 3" tall with a 1" bloom- wierd), and a few didn't come back at all.

I would leave the green so that it can replinsh the bulb and fertilize. The thing is that they may not be perfect next summer but I'm sure they will eventually recover and be fine.

Hi Judia,
This is pure speculation on my part (and whether it is useful or not depends on the number of bulbs you have) but have you thought of refrigerating them? Cooling them down would suppress additional growth without the damage of freezing. Once it is consistently cold outside you could plant them without danger of them growing again.

When you plant them, plant them deep (8"-10") and mulch well. The deeper earth has less of a temp. swing (in case of unseasonably warm or freezing weather) and protects them from squirrels.

If refrigerating won't work for you, I'd cut them back, mulch the heck out of them, and pray for cold (but not freezing) weather. If you didn't plant them deep enough in September, you may want to replant them deeper before mulching.
. -Helen

First year lilies can bloom weird no matter what when fall planted. Some species are very prone to problems with late frost. Italia being one that doesn't always do well even when established. Some of the doubles can have this problem also so it isn't just that they sprouted when you have a poor first year. When lilies show poorly you shoul break off the buds and leave the folliage. The next year you will have very healthy bulbs and flowers except on those that may get damaged from weather conditions. The doubles will do well in colder climates in some years and poorly in others. Fata Morgana is the exception and normally does very well after the first year. Cutting off the tops and leaving the stems would work only if there is time enough for the folliage to die naturally. I still maintain it wasn't just warmth but lilies who probably didn't get planted last summer. Asiatics can be stored up to 28 months and live. Some others died in testing after six months. What kind of lily are you talking about and where did you purchase it? I purchased some lilies that had a lot of week growth on them. Planted them in mid summer and removed the bud area. They bloomed nicely the second year. The principle is the same. I live in an area that has sporadic weather changes and lilies don't come up if we have a week or so of warm and then frost and warm again. They are not that speedy. I think they were ready to grow when the hit the soil. Buy from a grower rather than a distributor and they will replace you bulb if something was wrong with it. You are not saving money if you buy a cheap diseased bulb so be careful.