Temperature...it's all about...

[D.J. Wolf]

Temperature. Specifically nighttime low temps. Now, I remember growing up my mom and dad always saying that Squash and melons were fairly tough, and you could plant them as soon as you thought it wasn't going to freeze again. Lately though, I've been reading some information online saying that things like zucchini, watermelon, pumpkin, and cucumbers (what I'm planting) shouldn't go outside until lows are staying at or above 50.

So I need help and/or advice. Lowest forecast temp for the next 10 days (and I'm guessing the rest of the season), is like 45. Would I be safe planting out at least zucchini? I've got them started, and they are growing so fast in the starter tray that I'm going to have to do something with them soon!

[jmsieglaff]

Here's what I do, can't say it's right or wrong, but it seems to work.

Here in southern WI, I plant out tomatoes and peppers usually May 10-15. My dwarf tomatoes and peppers are in buckets, indeterminate tomatoes are in the slightly raised beds. I usually sow cucumbers a few days before I plant tomatoes. I start zucchini and vining summer squash in peat pots ahead of time and usually plant those out with tomatoes. Obviously I'm trying to avoid any frost, we usually get a couple cold nights, as low as upper 30s/low 40s in there....once I had to cover things like crazy for a late frost. I'm fairly aggressive on my plant outs as my raised beds and buckets offer warm soil, but if I'm in that May 10-15 window and no cold plunges are forecast I'll do it.

Things like honeydew, watermelon, or new to me this year--peanuts--I wait another 7-14 days as those things definitely do not like cold, even low 40s.

So depending on your risk tolerance, I think your cucumbers/squash/zukes can go out with your tomatoes--I would wait 1-2 weeks for melons/okra/peanuts or anything that really hates cold. Also, if you have a meat thermometer, stick it in the ground in the early morning and see what your soil temperatures are at about 4"--you'll want at least 65F I'd say.

[zipcode]

Under 5C the cucumber roots can't really take water and the plants look like they are freezing even if they technically aren't. 45F is above that, for zucchini it should be fine, but maybe not cucumbers and definitely not watermelon.

[D.J. Wolf]

Thanks everyone! Watermelons can wait another week maybe I think. Zucchini is the big one, they just shot out of the little starter pots and I'm having problems trying to keep them growing straight up and not tipping over! The watermelon are the second tallest so far, but they're not trying to tip bad yet.

[GoDawgs]

Try using some wooden bbq skewers as mini stakes for your zucchini. They work great!

[D.J. Wolf]

Originally Posted by GoDawgs

Try using some wooden bbq skewers as mini stakes for your zucchini. They work great!

Thanks for the tip GoDawgs! I ended up taking the 6 tallest zucchini's and replanting them into a great big pot I had. Planted them as deep as I could so they can't really tip now!

The weather refuses to cooperate. I almost had decided to just plant them and hope for the best, but the forecast for the next week has the lows in the lower 40's, not going to see lows of 50+ until next Sunday the way it looks now

[Gardeneer]

Originally Posted by D.J. Wolf

Thanks everyone! Watermelons can wait another week maybe I think. Zucchini is the big one, they just shot out of the little starter pots and I'm having problems trying to keep them growing straight up and not tipping over! The watermelon are the second tallest so far, but they're not trying to tip bad yet.

I always direct sow cukes, zukes, melons ...right around tomato plant out time.

The reason being that the are quite fast growing.

They are more cold sensitive than tomatoes. Just this year cold snap killed most of them except butter4nut squash. Night lows got down to slow 30s, NO frost.

Nothing happen to the tomatoes.

[D.J. Wolf]

Gardeneer, I would usually have direct planted them. But I had to replant some tomatoes, so since I had a tray and soil out, I decided to go ahead and get them started. Second guessing that decision now with the weather playing around. However, on a good note, it's looking like by the end of this week we'll have lows up into the 60's instead of the 40's and out they'll go!

[PaulF]

For the past several years the nighttime temps have stayed above 50F here after May 5. This year that will happen around May 15. Tomatoes and peppers will go in the ground then for me. Usually I pay more attention to soil temperatures for squash, cubes and other vining crops. I like 65 degrees F or higher. That may happen a few days later than the norm also.

When people ask me about how early they can plant, I always say that it is better to wait a few days for the right conditions rather than force the issue and risk having to replant. Everything will catch up even if put in a week later.

[ddsack]

I don't worry about 40-50F night time lows, as long as the days have lots of sun and temperatures in the high 60's and 70's. I wouldn't get anything planted until after mid-June, if I did. I already have a short season, so that's not an option.

As long as the daylight hours have good sunny growing weather, I don't think a few colder nights have any permanent effect. Now, if the days are cold and cloudy as well for an extended period, that's different.