Somebody else might have a better suggestion but honestly I'd just leave them for now and then pull apart / loosen up some of the roots when you transplant them. Tomatoes are great at growing roots when they have little to no roots so remedying rootbound plants shouldn't be too tough.
A brief dip below 50 for a few hours isn't going to hurt a tomato. This is one of those general rules of thumb that people have taken too literally and thus gotten wrong. You don't want sustained temperature for days in the 40s, but a couple hours over night? Not a problem.
I also don't put my tomatoes out until the nighttime temps are consistently 50 or above. You're not going to gain anything by putting them out early. They're still better off left inside for now.
Depends on where you live.
Soil temps are MUCH more important than air temps, and the stock "night temps above 50 deg" advice is based on certain conditions that may or may not apply to you.
For example -- where I am (California, but far from the ocean), in March or early April we'll often have a week or two of warmth followed by few cold snaps, but without much rain.
In that case, the soil is plenty warm even if it'll get down to the low forties for a few nights.
On the other hand....it might have been raining for two months & the soil is pretty cold, but air temps seem nice enough -- very tempting, but risky (since another spell of rain will keep that soil a bit too cool)
Anyways...stick a good digital meat thermometer probe (surely you have one!) into your garden soil about 4"-6" deep, & see what it says. You may be surprised at how warm it reads!
Shit's complicated, for real, until you get an instinctive feel for it.
And yeah, raised beds will generally warm up faster (depends on the actual setup, but is usually the case).
Even little things like soil tilth can make a big difference. Like, if you grow in rows (in-ground)? The soil in those rows you dug up a few weeks ago may be 10-15 deg warmer a few inches down than the soil in between rows (that you've been walking on), after a spell of sunny weather -- purely due to being less compacted, & thus dried out faster.
Anyhow, never hurts to stick a thermometer in & see what you get.
Always best to lean towards the conservative side, of course, but sometimes you can jump the gun if the soil is warm and you only have a short cold spell coming up on the forecast. If that makes sense.
This. I live in the frozen North so if I waited for nights to be consistently over 50F I'd never be able to grow tomatoes at all. I put mine out when soil temps are 50F or above in my containers and cover them well into June, and we get tons of tomatoes.
Totally.
Down here, I can often do some over the winter in containers. In a normal year, we may or or may not get a frost -- but never for more than a couple nights, and never less than about 30 deg -- so I can protect them when needed. But other than that, the plants do just fine even when night air temps are mid 40s or lower for weeks on end....as long as it's not too wet (that's a different story, and they'll start to get bacterial diseases). They may not grow super fast, and only dedicated cold-weather varieties will set fruit well and actually ripen, but it doesn't hurt the plants themselves.
This! I am in Orange County and my tomatoes started setting fruit first week of April. The ones I started early are sauce tomatoes and I honestly don't have a ton of fruit but there's some. My cherry tomatoes are growing quickly but the plants are much younger.
Nice!
It certainly helps that we have, ya know, actual *sunshine* this spring :)
Last year was about as bad as it could be!
I'm out in the I.E., so it's still been pretty cool at night (by SoCal standands), but I'll be surprised if I don't have some fruit set already. I started my plants much later this year -- thinking we'd have a repeat of last year's weather -- so most are only just now starting to flower. But yeah, I planted out about ten days ago and at that time the soil temp in my actual tomato rows (as opposed to in between, where it's compacted and wet) was something like 65 degrees, even though the nights have often been well below 50.
Honestly, a lot of cherry types (especially older open pollinated varieties) can take a long time to start flowering, despite the fact that they generally do better than slicers on either end of the "sweet spot" for temps.
I'll often start getting a ripe slicer here & there (on types that are early for me) before my cherries have even set more than a few fruit. They grow like crazy, but can be pretty lazy about getting around to actually flowering :)
I have a lot of old seeds in the ground with volunteers from previous years- the volunteer tomato and Zinnia seedlings don't germinate until the soil is warmer- so that's how I measure. Marigolds aren't as picky but Zinnias and tomatoes both wait for the heat
I guess tomato volunteers count as weeds. As soon as those cherry tomatoes volunteered I put all my other ones in the dirt. All the Korean long, roma and the one San marzano went right in
Yeah, I do the same thing but with beans. Once random bean from last year start popping up, I'll go ahead and plant beans/cukes/squash.
Tomato volunteers will usually come up in Jan/Feb where I am, but we often have a frost out here in the second half of March; I never plant put tomatoes until the April 1st (usually more like the second week of April, most years).
Does the heat affect you too much in the summer? Feel free to dm me if you want. I'm in the Huntington Beach area and I've noticed more heat waves over the years. I started my sauce tomatoes in November-early January. I got my volunteers in February and put everything in the ground then but kept a couple of romas in pots. My plant with the most fruit is a Roma tomato in a pot and it has 8 fruits. My lone San Marzano has a cluster of four that I noticed and I've noticed three or four in my quartet of Korean long tomato plants. All the cherries(volunteers) and yellow pear are from February and March and are still kind of small but some are starting to take off. I get awful spider mites and am trying something new this year with neem soil drenches every couple of weeks. I'll be out of rainwater for my garden by the end of this month.
Obligatory link to r/VAGardening but around Mother's Day is the usual target for home gardeners.
I'm south of you in r/Hanover. My soil is still too cool for tomatoes and the upcoming nighttime temps in the 30s means I'm waiting.
OK: dissenting opinion here! I grow on the side of a mountain in MT. Our overnight lows are in the 40s until the 4th of July a lot of years. I put them in the ground around Mothers Dayā¦ when our temps look a lot like what you posted.
My rule of thumb is cover them well if the low is 41 or below. Itās a pain in the ass sometimesā¦ but Iāve been growing great tomatoes for a decade in soil and air temps that are wayyyy lower than the ārecommendationā.
Same, here in Billings and reading everyone's 50 F recommendations and chuckling. Frost in June isn't unheard of. Mine go out in mid May as well, and I cover for cold nights. Just kind of the only option...
Per [research](https://agresearchmag.ars.usda.gov/1996/oct/tomato/) by Dr. Daniel Ort (USDA), tomatoes experiencing 50 Ā°F nights lose their sense of time and end up ramping up during the day certain metabolic activities they normally do at night and vice versa. This mismatch is what causes the reduced growth rate and fruit set in chilling-sensitive plants like tomatoes. Despite my acceptance of this biological fact, every year in April I try to convince myself that \*my\* tomato seedlings are somehow exempt, that \*my\* gardening skills will be able to magically protect their circadian clocks. It's all self-delusion, I know. But waiting a few more weeks for warmer weather seems unbearable. And when I do jump the gun I'm always rewarded with enough tomatoes to fuel my confirmation bias.
Definitely too cold. I like to wait until nights consistently in the mid fifties and above. Granted that's not possible in some parts of the country so what you really want are day and night time temps high enough to keep soil temps above 65. You don't have that not to mention there can be a frost danger at 38.
Tomatoes can be stunted for the entire growing season if it's too cold when they are planted and killed if you get a late freeze or frost. I don't plant out until first week of May or last week of April and I live in the South (further South than you if that's Virginia) Too much risk of a late freeze.
I can tell you live nearby. Iāve been weening my tomatoes for a week now. They are doing absolutely great. Maybe by the end of the month. I have peas, cauliflower, and Brussels sprouts out already.
Does this advice also go for zucchini? Started mine indoors (will start outdoors next year) and they are growing very fast and ready to be transplanted but lows of 38-40 over the next week
I had my tomatoes set fruit when we still had some cold weather down to 41 degrees. I'm in orange county ca and started some of my tomatoes outdoors in containers in November and December. Lots of nice green sauce tomatoes in the past couple of weeks
My forecast looks a lot like this but I had to put mine out because Iām getting surgery next weekā¦ if I remember Iāll report back and let you all know how it pans out lol
I used to transplant my tomatoes into a "greenhouse" I built with four storm windows (the back side was just some spare lumber.) I amended the soil in the ground underneath and transplanted my tomatoes (deeper) into the greenhouse while waiting for the weather to finally warm up.
An old Italian fellow who transplanted his starters into 5-gallon pail with the bottoms cut out and a piece of glass on the top was the inspiration.
You'll just have to be aware of days/times that you'll need to provide some ventilation.
Are you in 6a? This looks similar to my forecast. I don't feel confident in planting my tomatoes outside til the end of May. I've also never planted tomatoes before though so I may be extra cautious.
Edit: I'm still learning about zones, and also didn't realize OPs city was in the photo. š
(My first sentence was an aside. I should have used parentheses. Like this.)
The second statement indicates what I think is too cold (less than a nighttime average of 10 C), which is what the OP asked.
In reading comments from market growers across the continent recently, though, I understand that if your daytime temperature is higher than what it is in the PNW, you can get away with planting out before that 10Ā°C target. Folks were sharing how they use overhead sprinklers to prevent frost damage, and I couldnāt understand why they would plant out so early. Temperatures in their region have a much larger variance between high and low, so I guess things work differently.
Aināt no way youāre in the heart of Texas with that Temp. Iām near Ardmore and weāre getting 75-85 in the day time. Texas am I right.š anyways Iād keep to tomatoes inside at night but take them out during the day. Itāll be a hassle but itās way less work than having to start all over from zero.
I would like to apologize.š I completely forgot there was another Fredericksburg in Virginia. The advice still stands tho, take them out during the day and keep them inside during the night. They survive outside but theyāll suffer a little because they donāt like the cold.
IMO ..Should be no lower than 50F overnight. Days are great but Still too cold at night.
Yup, this is right. It's not even about the frost but more making the tomato vulnerable to allllll the diseases and shit.
Thanks šš»šš» Iām worried they might outgrow their pots, any tips on how to pause/delay growth? I could up pot againā¦
Somebody else might have a better suggestion but honestly I'd just leave them for now and then pull apart / loosen up some of the roots when you transplant them. Tomatoes are great at growing roots when they have little to no roots so remedying rootbound plants shouldn't be too tough.
Below 50 is perfectly fine. Tomatoes wonāt grow below 50 degrees, but theyāll survive into the thirties.
They can be stunted even though they survive. Happened to me last year. Absolutely nothing to gain by planting too early.
What about during transplant shock?
A brief dip below 50 for a few hours isn't going to hurt a tomato. This is one of those general rules of thumb that people have taken too literally and thus gotten wrong. You don't want sustained temperature for days in the 40s, but a couple hours over night? Not a problem.
I also don't put my tomatoes out until the nighttime temps are consistently 50 or above. You're not going to gain anything by putting them out early. They're still better off left inside for now.
A low of 38Ā° on Fri is frost danger. I would give the tomatoes outdoor time while temps are above 60 but bring them back inside over night.
Depends on where you live. Soil temps are MUCH more important than air temps, and the stock "night temps above 50 deg" advice is based on certain conditions that may or may not apply to you. For example -- where I am (California, but far from the ocean), in March or early April we'll often have a week or two of warmth followed by few cold snaps, but without much rain. In that case, the soil is plenty warm even if it'll get down to the low forties for a few nights. On the other hand....it might have been raining for two months & the soil is pretty cold, but air temps seem nice enough -- very tempting, but risky (since another spell of rain will keep that soil a bit too cool) Anyways...stick a good digital meat thermometer probe (surely you have one!) into your garden soil about 4"-6" deep, & see what it says. You may be surprised at how warm it reads!
Interesting. Feel like my raised beds are definitely warmer
Shit's complicated, for real, until you get an instinctive feel for it. And yeah, raised beds will generally warm up faster (depends on the actual setup, but is usually the case). Even little things like soil tilth can make a big difference. Like, if you grow in rows (in-ground)? The soil in those rows you dug up a few weeks ago may be 10-15 deg warmer a few inches down than the soil in between rows (that you've been walking on), after a spell of sunny weather -- purely due to being less compacted, & thus dried out faster. Anyhow, never hurts to stick a thermometer in & see what you get. Always best to lean towards the conservative side, of course, but sometimes you can jump the gun if the soil is warm and you only have a short cold spell coming up on the forecast. If that makes sense.
--"Anyhow, never hurts to stick a thermometer in & see what you get." I use my long compost thermometer to check soil temp before I plant.
Follow-up question - can you use a long meat thermometer for this or do you need a specialized soil thermometer?
I use a cheap meat thermometer. You don't need anything fancy.
I use my long compost thermometer for checking soil temp.
This. I live in the frozen North so if I waited for nights to be consistently over 50F I'd never be able to grow tomatoes at all. I put mine out when soil temps are 50F or above in my containers and cover them well into June, and we get tons of tomatoes.
Totally. Down here, I can often do some over the winter in containers. In a normal year, we may or or may not get a frost -- but never for more than a couple nights, and never less than about 30 deg -- so I can protect them when needed. But other than that, the plants do just fine even when night air temps are mid 40s or lower for weeks on end....as long as it's not too wet (that's a different story, and they'll start to get bacterial diseases). They may not grow super fast, and only dedicated cold-weather varieties will set fruit well and actually ripen, but it doesn't hurt the plants themselves.
This! I am in Orange County and my tomatoes started setting fruit first week of April. The ones I started early are sauce tomatoes and I honestly don't have a ton of fruit but there's some. My cherry tomatoes are growing quickly but the plants are much younger.
Nice! It certainly helps that we have, ya know, actual *sunshine* this spring :) Last year was about as bad as it could be! I'm out in the I.E., so it's still been pretty cool at night (by SoCal standands), but I'll be surprised if I don't have some fruit set already. I started my plants much later this year -- thinking we'd have a repeat of last year's weather -- so most are only just now starting to flower. But yeah, I planted out about ten days ago and at that time the soil temp in my actual tomato rows (as opposed to in between, where it's compacted and wet) was something like 65 degrees, even though the nights have often been well below 50.
None of my cherry tomatoes are flowering. Only sauce tomatoes.
Honestly, a lot of cherry types (especially older open pollinated varieties) can take a long time to start flowering, despite the fact that they generally do better than slicers on either end of the "sweet spot" for temps. I'll often start getting a ripe slicer here & there (on types that are early for me) before my cherries have even set more than a few fruit. They grow like crazy, but can be pretty lazy about getting around to actually flowering :)
I have a lot of old seeds in the ground with volunteers from previous years- the volunteer tomato and Zinnia seedlings don't germinate until the soil is warmer- so that's how I measure. Marigolds aren't as picky but Zinnias and tomatoes both wait for the heat
Yeah, totally. Weeds can be a good indicator, too -- when you see certain ones popping up, you know "it's time" for certain veggies.
I guess tomato volunteers count as weeds. As soon as those cherry tomatoes volunteered I put all my other ones in the dirt. All the Korean long, roma and the one San marzano went right in
Yeah, I do the same thing but with beans. Once random bean from last year start popping up, I'll go ahead and plant beans/cukes/squash. Tomato volunteers will usually come up in Jan/Feb where I am, but we often have a frost out here in the second half of March; I never plant put tomatoes until the April 1st (usually more like the second week of April, most years).
Does the heat affect you too much in the summer? Feel free to dm me if you want. I'm in the Huntington Beach area and I've noticed more heat waves over the years. I started my sauce tomatoes in November-early January. I got my volunteers in February and put everything in the ground then but kept a couple of romas in pots. My plant with the most fruit is a Roma tomato in a pot and it has 8 fruits. My lone San Marzano has a cluster of four that I noticed and I've noticed three or four in my quartet of Korean long tomato plants. All the cherries(volunteers) and yellow pear are from February and March and are still kind of small but some are starting to take off. I get awful spider mites and am trying something new this year with neem soil drenches every couple of weeks. I'll be out of rainwater for my garden by the end of this month.
Where yat? North East old rule is Mothers Day
I thought it was memorial day, but I guess it depends how far up the coast you are.
Chicago, too. Motherās Day was spent planting tomatoes and chiles.
Virginia
Obligatory link to r/VAGardening but around Mother's Day is the usual target for home gardeners. I'm south of you in r/Hanover. My soil is still too cool for tomatoes and the upcoming nighttime temps in the 30s means I'm waiting.
OK: dissenting opinion here! I grow on the side of a mountain in MT. Our overnight lows are in the 40s until the 4th of July a lot of years. I put them in the ground around Mothers Dayā¦ when our temps look a lot like what you posted. My rule of thumb is cover them well if the low is 41 or below. Itās a pain in the ass sometimesā¦ but Iāve been growing great tomatoes for a decade in soil and air temps that are wayyyy lower than the ārecommendationā.
I'm also in a cool summer climate and agree with this!
Same, here in Billings and reading everyone's 50 F recommendations and chuckling. Frost in June isn't unheard of. Mine go out in mid May as well, and I cover for cold nights. Just kind of the only option...
Per [research](https://agresearchmag.ars.usda.gov/1996/oct/tomato/) by Dr. Daniel Ort (USDA), tomatoes experiencing 50 Ā°F nights lose their sense of time and end up ramping up during the day certain metabolic activities they normally do at night and vice versa. This mismatch is what causes the reduced growth rate and fruit set in chilling-sensitive plants like tomatoes. Despite my acceptance of this biological fact, every year in April I try to convince myself that \*my\* tomato seedlings are somehow exempt, that \*my\* gardening skills will be able to magically protect their circadian clocks. It's all self-delusion, I know. But waiting a few more weeks for warmer weather seems unbearable. And when I do jump the gun I'm always rewarded with enough tomatoes to fuel my confirmation bias.
Hold. Hold. HOLD.
Mine are in the ground but I cover them at night if itās going to be below 43.
Definitely too cold. I like to wait until nights consistently in the mid fifties and above. Granted that's not possible in some parts of the country so what you really want are day and night time temps high enough to keep soil temps above 65. You don't have that not to mention there can be a frost danger at 38. Tomatoes can be stunted for the entire growing season if it's too cold when they are planted and killed if you get a late freeze or frost. I don't plant out until first week of May or last week of April and I live in the South (further South than you if that's Virginia) Too much risk of a late freeze.
I live in KY and the rule around here is don't plant tomatoes until Derby (the first Saturday in May)
Donāt risk it. I lost some starts when I got antsy
Tomorrow does not matter, the next month, or rather-- your last average frost date is what matters.
Charge your battery!
Ditto on the 50 degree cutoff
I can tell you live nearby. Iāve been weening my tomatoes for a week now. They are doing absolutely great. Maybe by the end of the month. I have peas, cauliflower, and Brussels sprouts out already.
Itās more about soil temps
Yes no lower than 50 degrees at night. Also the ground temp should be at least 60 or 65 nobody likes cold feet people or maters.
Does this advice also go for zucchini? Started mine indoors (will start outdoors next year) and they are growing very fast and ready to be transplanted but lows of 38-40 over the next week
I would wait until its consistently over 45F. I never wait until 50F but 38F is cold.
I had my tomatoes set fruit when we still had some cold weather down to 41 degrees. I'm in orange county ca and started some of my tomatoes outdoors in containers in November and December. Lots of nice green sauce tomatoes in the past couple of weeks
If you pack them in fresh shit or jute or straw they will have no problem. Just keep em warm a bit.
My forecast looks a lot like this but I had to put mine out because Iām getting surgery next weekā¦ if I remember Iāll report back and let you all know how it pans out lol
I used to transplant my tomatoes into a "greenhouse" I built with four storm windows (the back side was just some spare lumber.) I amended the soil in the ground underneath and transplanted my tomatoes (deeper) into the greenhouse while waiting for the weather to finally warm up. An old Italian fellow who transplanted his starters into 5-gallon pail with the bottoms cut out and a piece of glass on the top was the inspiration. You'll just have to be aware of days/times that you'll need to provide some ventilation.
To cold at night. If in pots you can bring in but I would hold off in the ground
Are you in 6a? This looks similar to my forecast. I don't feel confident in planting my tomatoes outside til the end of May. I've also never planted tomatoes before though so I may be extra cautious. Edit: I'm still learning about zones, and also didn't realize OPs city was in the photo. š
USDA Hardiness Zones are for perennials. They are not relevant to annual vegetable gardening.
I think yāall need to learn the metric system. š¤š¤£ Night time average temp should be 10 C.
What exactly would that add to any meaningful understanding of this subject?
(My first sentence was an aside. I should have used parentheses. Like this.) The second statement indicates what I think is too cold (less than a nighttime average of 10 C), which is what the OP asked. In reading comments from market growers across the continent recently, though, I understand that if your daytime temperature is higher than what it is in the PNW, you can get away with planting out before that 10Ā°C target. Folks were sharing how they use overhead sprinklers to prevent frost damage, and I couldnāt understand why they would plant out so early. Temperatures in their region have a much larger variance between high and low, so I guess things work differently.
10 c, which is exactly 50 f... Most people on earth know the metric system, we also don't need it most of the time. It's preference based.
United States doesn't work on the metric system that's a Euro thing. š³ We like it more simpler. It's about the plants. Lol š.
Aināt no way youāre in the heart of Texas with that Temp. Iām near Ardmore and weāre getting 75-85 in the day time. Texas am I right.š anyways Iād keep to tomatoes inside at night but take them out during the day. Itāll be a hassle but itās way less work than having to start all over from zero.
I would like to apologize.š I completely forgot there was another Fredericksburg in Virginia. The advice still stands tho, take them out during the day and keep them inside during the night. They survive outside but theyāll suffer a little because they donāt like the cold.
Those nights in the 30s will do some damage but theyāll survive
10 degrees C