Lettuce will not be harmed by light frost. Whether a plant is harmed by a frost or not depends on the plant and not the size, though new seedlings not acclimated to the cold (i.e. started indoors) can be damaged even with cold hardy plants. There are other discussions about this right now on the first page. Apparently others report it can survive hard freezes into very cold territory (that doesn't mean it will grow in such weather however.)

Sugar snap peas do fine down to temps in the low 20s. I believe that lettuce is OK with a LIGHT frost (down to 28F or so). As noted, it's not a matter of plant size, but about plant chemistry. If you want to protect plants from frost, *cover* them, including soil underneath. Ideally the cover shouldn't touch the plant. Do not *wrap* them. What you're trying to do is to hold onto the heat that is in the ground. You wrap a human to keep them warm because humans make heat. Plants don't.

If you have a tarp, use that, and seal up around the edges on the ground. Bricks, wood, whatever.

P.S. Note that beans and peas which are similarly sized plants and, in fact, both legumes, respond to frost entirely differently. Beans are killed by the slightest frost. Peas just stay happy when the lake freezes.

not really true. we have had frosts the last two nights. the toms, squash, peppers and eggplants are history. The beans, still alive.

That's not my experience, but it may be varietal. I always thought they were just as sensitive as those others.

I was also surprised, my Fortex pole beans were undamaged by last night's frost, the tomatoes 50%, the eggplants, peppers, and zucchini were mush. I think the bush beans were roasted but I didn't look close. Tonight will be in the 20's and if the pole beans survive I will be amazed.

Peppers are going to be a plant that will not survive the first frost? But Peas will?

I wouldn't have guessed that. Does that mean I need to pick all the peppers (even the small ones) no later than the day before the first nightly frost for risk of 'losing' them in some form? thanks for bringing this up, I didn't realize that.

I covered my peppers with very light weight row cover last night. The temps got down to 32 f. here in E. Tn. - they survived. I Covered them again this evening. Tonight was supposed to be 34, but it's already 33. If I can get through tonight, it looks like I can get another week or 2 before we get a killing frost.

Don't use plastic to cover plants, unless it's lifted off them by hoops or something. If your cover touches the plants, it must be row covers or cloth.

It was maybe 25F in my garden last night.

It was only supposed to get to 34 f last night. Early this morning it was 28. When I removed the light weight cover, I expected to see devastation... looks like they survived! Well, mostly survived lol. There was ice on the fabric, and some of the leaves look a bit weak, but over-all it looks good. Hopefully the forecast is right and we won't see anything under 40 for at least another week.

Last Friday they were predicting a low of 35 on Saturday morning here in KC and I live in a valley that often gets several degrees cooler than the 'official' reading. So I went out and picked several dozen green Bell peppers and Carmen peppers but left about 1/3 of them on the plants. Well it only got down to 41 with no frost so I am glad I left some.

Our 14 day forecast is showing highs in the 70s or 60s and lows in the mid 40s so hopefully still have a couple weeks before frost to ripen what I left. Last year we didn't get a frost until Nov 1 and then it went downhill fast and was single digit lows by Nov. 15.

Last winter I kept some TAM Jalapenos alive by burying them in plastic and blankets during freezes, where the temps went down to 25F. They survived, though parts of the plant touching cold plastic were killed, as were parts of the plants near gaps in the tiedowns. It was more effort than it was worth, as they bore poorly this summer season.

In a mild freeze, a lightweight cover will do fine for peppers. The temperature under the cover never goes below freezing because the ground underneath is much warmer than the air. For a heavy freeze, or late in the season when the ground is chilled, that won't work as well.

My peas were definitely damaged a bit by the 25-28F low. Still alive, though.

My sugar snap peas routinely survive 25F unscathed. One year, when the temp went down to 22F, some leaves were damaged, but the plants continued to grow well after that. I'm pretty sure, however, that if you have blooms when it freezes, those blooms will abort.

Yeah IDK - it was a really heavy freeze, pretty thick looking ice on everything. Maybe they were just unprepared, it was a large drop in temperature. Like I said they still are alive and growing, just some leaves damaged.

Re: beans, it depends on what beans you're referring to, Dan and Glib. Favas are even hardier than peas, but common beans are frost-tender. My favas have survived temps. down to mid-teens without protection.

The beans are marginally less frost sensitive than cucurbita and solanaceae. It could be just one degree less. In fact I had young bean plants survive frosts in May, too. I use well known varieties (Fortex, romano types, tongue of fire) from Johnny.

Whoa! Favas down to midteens. That's awesome. I've never grown them. Now that I read up on them, I see they are indeed a cool-season vegetable, and they don't like temps over 80F. In fact, it isn't really a regular green bean, but a vetch. It is said that they tolerate temps at least as low as peas do.

that is all true Dan. In Texas you can certainly grow them through the winter. Here in Michigan I would plant them in March, they germinate even in cold soil.By June they have made a thick stand and start to decline, getting diseases in the heat. By July they are history. The leaves are good to eat, both in salad and cooked, though the stems are fibrous. The production of bio-mass and nitrogen is way above average, I would say unique for a winter cover.

They really are a cold weather plant, used for winter cover and winter crop in Southern Europe for millennia. Before synthetic urea, there were only favas in that part of the world. Prisoners ate only favas, because they were plentiful but also a heavy bean to digest. So if you want to cover crop some of your beds, go ahead, you will be pleasantly surprised.

That's nice, except I'm more partial to snap beans than shell beans. Can favas be harvested when immature and used as snap beans? The idea of wintertime snap beans is attractive. Or more generally, are there any snap bean varieties with good frost tolerance? Of course, I usually grow sugar snap peas in the winter, but it would be nice to have winter legumes with thick pods but small seeds.

Although I've never tried harvesting immature fava bean pods, I have tried boiling the mature ones and find them borderline edible - just a bit too stringy. I think the immature ones would be good to eat as snap beans based on that observation.

no, in winter favas make only greens. they fruit all at once in spring in the South. for winter, it is greens and/or be happy for the fertilization. at any rate, cover favas have seeds very similar to soybeans in appearance. Favas for gardens have large, weird flat beans. Greens/plants from the two types are completely identical. The blooms have a wonderful smell. it is best to cook the fava seeds while still green, and slip off the tough skin (which is some work).

We call Favas Broad Beans. They are a very popular crop and I grow them every year. I sow in November and start harvesting in late May. For Spring sowing I'll put some in in late February but they and then in succession until May. We only eat the beans although some people eat the baby pods. We do eat the tips in mixed salads but the rest of the foliage soon becomes tough. If you are not used to Favas you might be disappointed if you don't realise the beans must either be eaten very young or, if allowed to get bigger, must be peeled. For dried beans obviously you can allow them to grow to maturity. We always use them when the beans are finger nail sized and tender. The nitrogen in the root nodules is a lucky incidental for me. I grow them to eat.

Glib is right about the flowers. They smell wonderful and are very unusual in being truly black and white.