Hey all... I live in Philadelphia and have a bunch of indeterminate beefsteaks, see photos. They are in large 30 gallon grow tubs, well-watered and fertilized etc.

I am getting significant blossom drop and am pretty sure it's due to heat stress... we're on average mid-upper 80s in July but have heat waves into the 90s with heat index near or over 100, gah! We also have periods of prolonged cloudiness. I'm pretty sure this is the cause of the blossom drop, and I understand some will be inevitable until temps moderate.

In the daytimes during heat waves I have covered flowers and tomatoes to prevent sunscald. Is this a good idea / anyone have other tips??

THANK YOU!

Sameer

hello, pet the dog for me

I am not sure what to say but I'm not that far from you, to the south, and my tomatoes in ground have plenty of blossoms and green fruit on.
Maybe being in containers adds a factor to the heat stress that I'm not getting here.

Have you heard that people shake the plants to get pollination? I wonder if lack of pollination could have made them drop, not set.

Not very helpful from me.. Surely some others will have comments too...

I am not sure, but a plastic bag may make it worse by keeping the heat in rather than keeping the sun out. I have seen shade cloth covering the whole plant used but never a bag over the fruit itself. Sun scald for me is generally whitish roundish splotches; yours look like bruising. As my plants grow larger with more foliage sunscald is less a problem.

I agree that blossom drop is most likely due to heat stress and it happens to us all. You do have nice fruit on the vines and will do OK from the looks of your photos.

Wouldn't the plastic baggies just cook the tomatoes? I mean, I wouldn't wear a bag out in the sun.

It doesn't even take a plastic baggy to cook tomatoes here. use a more natural shade than plastic, such as cloth. Yes, when days are above 90* and nights don't drop below 80*, the pollen gets 'cloggy and useless' and when blooms aren't pollinated they drop. Airflo is vital. I used a screen of bamboo grass last year for shade, but could have just gone with cardboard around the plant to cool the roots to help the plants. Container plants get hotter than ground planted ones...shade your pots, or sink them into the ground? Take those bad tomatoes off the vine, you lost them already

Definitely ditch the plastic bags! Shade cloth or floating row cover or afternoon shade if you can move those massive pots

As Kat noted, roots get hotter in pots than in the ground...especially in black pots. White fabric or plastic draped around the pot helps lower the temp. Also mulch the soil.
Those plants look super lush with huge leaves (enviable except for no tomatoes) and I'm not sure, is that soil really wet? Too much water and nitrogen fertilizer could be playing a role as well.

Thanks for the input yall, REALLY appreciate it and is hugely informing my next steps

Good catch Zoe, I couldn't sleep so got up after seeing those pics in my head.
IF your pics are color accurate skhetan, those dark green leaves tell us they are getting too much fertilizer, tomatoes typically have a more yellow cast like your 3rd picture of the ripening tomato with that 'bruise' on it, why is it yellow if it is a beefsteak? That bruise looks more like excess water damage causing internal rot.
You do know that when tomatoes ripen, they go from green, to a white color before changing again to orangish to red as they fully ripen? if they are red tomatoes.
Tomatoes aren't houseplants, but your tomato PLANTS are gorgeous- and leaves would tell you they were scalding before the fruit showed damage typically. Reminds me of the story my dad told me of a couple of milk cows, yeah, I know, but bear with me. One cow was gorgeous, beautiful looking, healthy, and gave a good bit of milk(which is the most important fact for a milk cow) but, the other cow? Poor thing, she looked all bones, tired, sad, but she gave 3x the milk the first cow had. All of her energy was being sent to do her job-make milk-and she did. Plants are that way, too. If you want a houseplant it can look gorgeous because that is its job, but if you want fruits, that plant needs different care to do the job the best it can.
Here in Houston, it is a weird year for plants, I literally have lost half of each plant I set out to grow, to hail, to deer, to weather. Not just weather, some of my plants seem to be reacting to solar flares this year. I hear the north is getting some of the southern heat this year, but tomato vines just stop setting fruit if it gets too hot for the fruit, the vines usually don't die from it, and where you live can return for summer harvests. For me, once we hit the 90*s steady, it doesn't cool down til Nov enough for our tomatoes. I wish you luck.

These are showing the excessive rain I am getting this year. 9 days into July and 5 of them have been rainy, 6 3/4" ttl rain so far.







It means they rot faster, are watery in taste, and a few other nasty side effects. Some of the best tomatoes I had were last year when we had no rain at all for months.

NMoasis said: Definitely ditch the plastic bags! Shade cloth or floating row cover or afternoon shade if you can move those massive pots

As Kat noted, roots get hotter in pots than in the ground...especially in black pots. White fabric or plastic draped around the pot helps lower the temp. Also mulch the soil.
Those plants look super lush with huge leaves (enviable except for no tomatoes) and I'm not sure, is that soil really wet? Too much water and nitrogen fertilizer could be playing a role as well.

I agree on the nitrogen comment...for what my agreement is worth.

Our state (Alabama) extension office suggests that daytime temperatures in excess of 85F and/or nighttime temperatures exceeding 72F will contribute to tomato blossom drop. These are "one-off" temperature spikes but rather several consecutive days of these temperatures. As Kat mentioned, the pollen gets moist and clumpy and simply doesn't freely "move" as it does during favorable temperatures...the plants hold the blossoms for a few days waiting on pollination that never happens and finally it discards the aging, un-pollinated flower.

Having typed the above info I will state that me and my gardening buddy have both had tomatoes set at temperatures above these BUT blossom drop tends to be more prevalent and fruit-set happens less at the higher temperatures. Once the temperatures have gotten much beyond the low-90's the plants simply seem to revert to "I'm just trying to stay alive right now" mode. Just my newbie, uneducated comment.