In my experience any temp is OK as long as there is no frost nor freeze. Young plants are easier to protect than more mature plants (using floating row covers or supported row covers). This year I had to tent my entire bean patch with row covers for the 30.2 degree morning we had Feb. 20 - very late for us. There are pole beans just as quick as most bush beans, about 60 days. I recommend Algarve for a snap pole bean. Algarve is also very productive, but that is another story. I start my beans in four inch containers, two or three seeds in each. You are itching to get started. Here we are nearing the end of the bean season. The freezer is getting stuffed!

IMO, it's still too early for beans in the Upper Midwest; they are a warm weather crop. The plants might survive temps in the 40's, but they won't be healthy - or really start growing - until temps reach 70's day / 50's night.

Pole beans do well in our area when direct seeded, after soil has warmed. For me, that is usually somewhere between the last week of May & the first week of June (plus or minus, depending upon weather). As Shuffles mentioned, some pole beans are nearly as fast as bush beans; "Early Riser" and "Goldmarie" are two examples. Even the later pole beans are generally only 1-3 weeks later than their bush bean counterparts.

Barbge, you mentioned starting the beans in pots. Would they be staying in pots, or is the plan to transplant them into the garden when the weather warms? If the intention is to transplant, then plants started this early would be pot bound & stunted by planting time. My recommendation would be to start them no earlier than 3 weeks before the date you would normally expect to plant beans in the ground. Those started earlier than that may not gain much time over healthier transplants started later.

I can & do use pole bean transplants, quite a few each year... but only if I am trying to get dry seed, where every extra week counts. If growing beans for snaps only, you can get a good crop direct seeded, even with pole beans... and even planted late. I planted the pole variety "Emerite" (which I highly recommend) over the July 4th weekend last year, and harvested enough to give away buckets full.

Hey zeedman. They will be grown in pots all summer. I do balcony gardening since I live in a townhome. Also, where are you from in Wisconsin? I now live in Minnesota, but I grew up a little north of Madison.

I'm quite a bit North of Madison, in Winnebago County. My main garden is rural, 6 miles West of my home... and even that close, it tends to get hard frost 7-10 days earlier than the gardens near my home. Chances are that your balcony garden will also be slightly warmer than the surrounding area, if you are urban and/or have a Southern exposure.

If the plants will be grown to maturity in pots - and you want a fairly decent yield - I would recommend the largest pots you can safely handle. For seed saving purposes, I grow one pole bean variety each year in 20" pots, with 3 plants per pot.