I pulled this from imternational ag lab.

"One of the simpler ways to get tomatoes to set fruit in a backyard garden is to put 2 cups of vinegar and 1 cup of BoPeep ammonia in 5 gallons of water and. sprinkle lightly over the plants and soil. This may need to be repeated two or three times to get a good set and keep the plants fruiting. I have done this for small garden plots as well as commercial-sized fields of tomatoes."

I guess it must work, but i would be cautious. Just the word ammonia scares me off. Are you having problems with fruit set?

No problems yet but the heat is coming. The guy I talked to grows to sell. He sprayed his when it got hot. He also used the soft rock phosphate they recommend on that site.

Sheila,
I had never visited the Ag Labs site. It has some very informational reading. I didn't see anywhere where it said it would increase fruit set in high temps. It might. I have visited lots of forums and sites and seen this issue hashed and rehashed and don't ever remember reading that it did. A person could do a comparison tests on two plants and see if they saw any difference. Did he use the soft rock phosphate or the super hard rock 0-20-0 that also recommend on the site? If you try it please keep us informed. If I had more time it would be interesting to try. Jay

Sheila,

I am inclined to agree with Jay. Feeding a plant with high phosphorus to induce blooming in order to get fruit set before the insane heat arrives (as early as just a couple of days from now in my county) is a very specific method we use in order to get fruit set before the heat shuts it down. Sometimes, if we have a prolonged cold front of, let's say, 3-5 days, forecasted in the summer, we can feed our plants a bloom booster and they will set fruit during that cold spell, even though the summer temperatures have prevented fruit from setting in general. Once your nighttime highs are in the 72-75 degree range and day-time highs are in the 92-95 degree range, fruit set becomes iffy, and it is even worse in humid years. By using a well-timed application of a bloom booster fertilizer in advance of high temperatures, or during a break from high temperatures, a person often can get fruit set later in the summer than usual.

What the Ag Labs website advocates applies more to their overall recommendations for developing healthy soil and getting good yields without the use of synthetic fertilizers. I cannot imagine how ammonia would help fruit set, especially as related to high temperatures. No amount of ammonia or vinegar is going to override the effect of high heat/humidity.

Dawn

To go off track just a little bit, is anyone else seeing a lot of blossom drop on their late planted tomatos? Im thinking mine is due to lack of sun and a lot of wind.

oh gosh Jay, I'm not sure. That conversation was way back in the spring. I can find out for sure though. Someone has his number at the greenhouses. I know he said it was kind of hard to find but he had found a source that was relatively cheap. Cant remember where he lives either. Man I have no memory. Remember junk I dont need to but cant remember important parts. Guess thats what you call part-timers. Sheila

Sheila I have "old timers" so know full well what you mean. Dawn stated what I was thinking in a more eloquent way. There are so many variables in gardening I don't ever say something didn't/doesn't work for someone. But from my experience and that of the many gardeners who are much more knowledgeable than I am I not only have never heard of using ammonia for increasing bloom set I have to admit I'm like Dawn and don't understand how it would increase fruit set in high temperatures. . First I would ask what does he consider high temps? Some consider 90 high temp. Personally depending on conditions and varieties I can get some fruit set here up to 95-96 daytime temps if the night temps are dropping into the 60's. Above that and I get very little if any fruit set on anything but cherry types. And everyone I've listened to and read state something very similar. Here I don't have the humidity usually so that aids me over many in other areas. I'm always one trying to learn so it has sparked my interest and desire to know more about how it does it and the variables involved. I do use a liquid fertilizer like Dawn stated a few days ahead of an expected cool spell to boost the blooms. Although from transplant till I have a decent fruit set or the plants get a good size I feed them with a fertilizer I mix with a high P number. It also encourages good root growth.

Erod I haven't seen much blossom drop yet. Very little. But expect I will start seeing more after this week and the high temps. The two main causes I have of blossom drop are heat and humidity. Most often it is heat here. For some reason the winds don't seem to cause much for me and the Lord knows we get our share of it here. Jay

I want to stress Jay's point about cool nights and also humidity and their effect on tomato fruit set.

To me, it seems like it is more the higher low temperatures at night that impedes fruit set than the higher high temperatures during the day. That's just based on what I observe here at our house.

With humidity, this is a lesson I learned not too long after we moved here. We were having an insane hot spell, with some daytime highs in the 108-111 degree range, and yet, the Better Boys and Big Boys I had planted for fall tomatoes were loaded down with flowers and were setting huge loads of fruit in early to mid-August in insane heat. In this case, it wasn't the night-time lows because they were usually in the lower 80s. Why were we getting fruit set then with such hot nights and hot days? Well, our humidity was very low during that time, often bottoming out in the single digits in late afternoon. Two years after that, we had another drought with very high temperatures and very low humidities and once again got great fruit set. So, if you live in a part of OK that might have either cool nights combined with very hot days, or very low humidity when temperatures are high, you may find you get fruit set at times that you really don't expect it because your daytime temperatures are so high. For the last couple of years, I've noticed that Phoenix F-1, a heat-setting type, has set fruit when daytime highs are over 110 degrees and humidity is low. However, so did some heirloom varieties that were not bred to be heat-setters as far as we know.

That brings up the subject of heat setting tomatoes. There is a group of tomato varieties developed by breeders that are said to set fruit at higher temperatures. Unfortunately, there are a couple of drawbacks to growing them. First, they only set fruit at air temps just a very few degrees higher than regular varieties, and when it gets hot here, it often gets way above the level at which you'd expect even a heat setter to set fruit. (Phoenix is the first heat set type I've had set fruit at temps above 110 degrees.) Secondly, they clearly were bred for their heat setting ability, and after tasting the fruit from many of the heat setting types, I can assure you that they were not bred for flavor. Yes, their fruit still is better than grocery store tomatoes, but only just barely. The best heat-setter with the best flavor was Merced, but the seed company stopped producing its seed long ago, and I haven't found one since that is its equal. Flavor is subjective, though, and we each have taste buds that perceive flavor in their own unique way, so someone else might like the flavor of the heat-setting types just fine.

For anyone reading this who is really new to growing tomatoes or who just hasn't thought about the effect of temperatures on fruit set, it is a well-known and fairly well-understood issue. Heat denatures pollen and impedes its ability to fertilize. Heat and high humidity also make pollen 'sticky' so it doesn't move around inside the flower at times as well as it needs to in order for fertilization to occur.

Sometimes people mistakenly believe their tomatoes aren't setting fruit because of a lack of insect activity, but tomatoes are self-pollinating and really don't need the assistance of insects. However, insects can help by moving the flowers around a little as they visit them, which makes the pollen move around. One way you can try to help your tomatoes is to thump the flowers when humidity is high. An occasional thumping, especially during the cooler parts of the day, can assist in shaking the sticky pollen loose and causing it to move around inside the flower, thereby pollinating and fertilizing the flower and giving your fruit set.

Thumping every flower would take a long time. Texas garden guru Neil Sperry used to say (and maybe he still does) you could walk down a row of caged tomatoes and give each cage a couple of good whacks with a tennis racket and that would give the flowers a good shake. I've done something similar by walking down the row and gently shaking each cage early in the morning.

Some tomatoes set fruit better in heat than others. Generally, the larger the fruit produced, the poorer the fruit set in extreme heat. Many cherry tomato plants set fruit at significantly higher temperatures than big beefsteaks tomatoes, for example. However, so do some of the varieties that set fruit in those in-between sizes that are not as small as cherries and also not as large as full-sized big slicers or big beefsteaks. Jaune Flammee is one variety that generally sets really well in high temperatures for me, and both Michael Pollan and Brown and Black Boar do too. Heidi is a paste type that sets fruit in very high temperatures, and Porter is larger than a cherry and is unstoppable in all but the worst heat.

Erod, I haven't seen any blossom drop yet, but our temperatures have been nice and we have had plenty of rain (and lots of wind). There are multiple reasons you may see blossom drop---not just high temperatures. Blossom drop can occur if the plants are receiving excess nitrogen. Blossom drop can occur not only in high temperatures, but also whenever the low temperatures drop below 55 degrees. Wind can indeed cause it, although as Jay noted, he has oodles of wind there in Kansas and he produces beautiful crops of tomatoes.

Sometimes it is hard to pinpoint why blooms are dropping. Look at your tomato foliage. If it is a deep, dark almost blue-green that is a sign of excess nitrogen that might explain it. If it is a medium green, then I doubt the issue is excessive nitrogen and would look more at cool nights, hot nights, hot days or high humidity. It could be some combination of all the above, combined with too much wind and rain.

I hope your flowers stop falling and you get some fruit set soon because our temperatures will start cranking up higher this week. I usually get good fruit set through almost the end of June even in a really hot and humid summer, so our plants "ought to" keep setting fruit for a while, but there's no guarantee.

Dawn

Dawn, that was a great post. My foliage is actually paler than it should be on the plants that are having blossom drop. The one plant that is only having mild blossom drop is just a medium, normal green, it has a few bby toms on it.

Looks like this year will be my year for patio tomatos.

Next time we have a cool snap, what type of bloom booster should I use? I'm thinking I should do it sinmce I am having so much blossom drop.

I'm fairly certain I do not have too much nitrogen, as I've not added any to that bed at all. I mixed in one small bag of garden soil and tilled it in really good a while efore I planted, but I do that every year with no problems. I do it because I use the same raised bed for tomatos every year.

Sorry to steal the thread, I hope the OP doesn't mind sharing with me....

Edit: I just looked over in the corner and saw the MC shake and feed that I spread lightly in the tomato patch just before memorial weekend, so about 2 weeks ago. I forgot all about it. My thinking was because they looked so pitiful from late freezes, no sunshine, etc was that they could use a little boost. It is equal parts Nitrogen, Phoisphate and Potash at 10% each and 20% Sulphurcould this be the culprit? If so, how do I remedy?

This post was edited by Erod1 on Sun, Jun 9, 13 at 18:29

I would like to make a comment about thumping the tomato blooms. I have my trellises made of T-post and at least one rebar running the length of the row. In the past I would walk by the end of the row and whack the end of that rebar and shake all 9 tomato plants in that row. I have not done that this year and I have more blossom drop and less fruit set than any other time I can remember. The shovel is in the garden leaning on one of the trellises. Instead of griping about blossom drop, why am I not whacking the rebar, it may not help, but it cant hurt any thing.

Larry

This thread is making me laugh! Coming from Albuquerque with no humidity and very cool nights, fruit set in the summer was never a problem, and I have been stressing out about the whole "fruit won't set in Oklahoma when it gets really hot" issue. I have literally gone out at least 5 times a day for the last three days to thump my tomato plants. My husband thinks I'm crazy, and I kept telling him emphatically (sounding kind of like a crazy woman, maybe) "Honey, after Tuesday fruit isn't going to set again until September!". Reading this thread and hearing that maybe fruit isn't going to immediately stop setting the first night the high is over 75 is making me feel much better! Although I will probably go out and thump the tomatoes one more time before bed.
It's interesting...in New Mexico, I definitely pruned suckers and pinched the first few blossoms of my plants...I'm so glad I found this forum to help with the transition to Oklahoma gardening. And, I will echo what was said above...I always had pretty good tomato crops there, and grew a lot of indeterminate varieties, and I have never, never, never seen plants so big. Bigger tomato cages will definitely be on my Christmas list.

Em, Thanks. I was trying to remember to include everything I could that would help gardeners who haven't had to deal with extreme heat and its effect on tomatoes. Sometimes I forget that people who recently moved here might have gardened in much milder summer weather than what we tend to see here.

What I do is watch the 7-day forecast and I always have a box, cannister or bag of bloom booster type fertilizer in the shed. About 3 to 5 days (5 is better than 3) before the expected arrival of cooler temperatures, I feed the plants with the bloom booster. That way, the plants are 'primed' and ready to bloom while the temperatures are cooler. You maybe could do it 7 days in advance, but the problem is that 7-day forecasts change a lot. You want your plants to be kicking into a flowering cycle as the cool spell hits so that any flowers they form during that time will have a chance of setting fruit.

I don't actually do this a lot because, normally, once my part of OK gets hot, it just stays hot and we don't get many summertime cold fronts. I know that I did it in 2009 quite successfully, and maybe in 2010 as well. SInce then, once summer arrives, we are mostly too hot all the time. Since you're further north and east than I am, you might get some cool spells a little more frequently than I do, but then most years you also have higher humidity which, as noted above, is its own complication.

It doesn't sound like your plants are getting too much nitrogen, but sometimes it can happen and you don't even know it so always keep it in mind as a possibility. For example, if your tomatoes are fairly close to a lawn, whether it is your lawn or someone else's lawn, and the lawn was fed with a time-release high-nitrogen fertilizer, then sometimes heavy rain may carry some of that nitrogen to your garden if the lawn area is directly adjacent to or sits on slightly higher ground. Sometimes (not that I am saying my husband ever would have done this) a spouse may fertilize the lawn with a rotary drop spreader and, if they happen to walk too close to your garden while doing this, the fertilizer spreader may send fertilizer into your garden. Even worse? If they are using a weed-and-feed product and the 'weed' part of it starts killing your plants. You have to think about all the angles---not just what you have done, but what someone else might have done. I have had tomatoes damaged more than once by herbicide drift from a nearby ranch.

I don't think the MG Shake and Feed would have stopped flower production. Now, if it had been a lawn fertilizer that is 33-0-0, that would be the culprit.

One important thing to do is to think like a tomato plant. As long as life is easy and cushy, a tomato doesn't have to get in any big hurry to do anything. If it has lots of water, lots of nice soil, fertilizer....an adoring human fan club....well, it is summertime and the living is easy so why rush? But, if you are thinking like a tomato, what will alarm you is when conditions get tougher. You dry out a bit, you aren't being fed fertilizer regularly, and insects are eating your leaves. You know your job is to produce seeds to perpetuate your species and keep it from going extinct, so you start blooming and setting fruit. In other words, plants respond really well to tough love. Try letting your tomato plants dry out some and get a little hungry. They may respond by putting on a new flush of flowers that will set fruit if the temperatures aren't too high.

I confess I am a very neglectful tomato parent. Once my plants are in the ground, and are staked, caged and mulched, about the only attention they get from me is that I pick their fruit. If they have lower leaves that are looking ratty, I pluck them off while I am picking fruit. If it isn't raining, I might water once a week, deeply, and then leave them alone the rest of the time. I don't obsess over anything except picking the fruit. I ignore most all insects and foliar diseases. I'd rather have plants that look progressively worse as the summer goes on than to spray chemicals on my plants. I get great harvests and can, freeze and dehydrate many hundreds of tomatoes a year. Why? Because I take super-good care of my plants? No. Because i leave them alone. Tomato plants suffer more from too much attention than too little. Trust me. Been there. Done that. I get the best yields when I leave them alone and let them do their thing. It sounds counter-intuitive, but it isn't. My work is done up front as I build the soil health every year, raise healthy seedlings, and put then in the ground and then let them do their thing the way nature intended. Some people are real hands-on, pruning, pinching out suckers, thumping all the flowers every day, feeding regularly, watering way too much.....I am the opposite. We have acreage filled with everything from prairie grasses and forbs to trees to fungi like mushrooms, slime mold, lichens on the trees, etc. How much do I help any of those plants? Pretty much not at all. They do just fine. Sometimes I think we humans fret too much and try too hard to help our plants, when maybe we should just leave them alone and let them be.

Larry, I agree that it likely will not hurt. I think your weather has been working against you lately with all the rain and clouds, but now that sunshine and heat are in control, you ought to get great fruit set, at least until the temps get too high.

Dawn

Dawn, the best crop of tomatos i ever had were the ones i left alone and watered once a week, so i need to remember that and do it again. It was about 12 years ago and i planted 36 plants and had tomatos put the wazoo!

We do have a lawn service that comes 6 times a year and they do something different each time. Pre emergant, post emergant, feed, etc. the last time they came was in April. So that might be my problem. Thanks for reminding me of that. When i first hired them, they used a spray system from their truck and my lawn always looked beautiful. Last year and this summer i noticed that they are using granules in one of these push spreaders. And i bet they got some of it in my raised bed. And my lawn looks terrible. I have weeds everywhere. I guess a call to cancel service is in order as ive noticed a bit of algae in my pond as well. Im sure it ran off with all the rains. I never had that problem when they used the spray. I do love a nice green lawn for my grandbabies to run barefoot in, have picnics, etc. but i have plenty of room for it, we sit on almost 100 acres, a lot of it wooded, about 20 to 35 of it he hays each year and about 20 of it we have a bunch of goats.

I bought some MC bloom booster to put in my watering can for my patio flowers, would that work on my tomatos? I beleive it says for plants and vegetables and has a pic of a tomato on it. I really doubt we will get any cold fronts once the heat sets in, it usually stays hot here. but with this years weather, who knows. And our 7 day forecast seems to change daily here too.

Maybe i should take your advice and my own advice and just leave em alone and let them grow.

Emma, The MG bloom booster would work just fine. You could try it once and see if it makes a visible difference. We are rapidly approaching the point where the temperatures will be in control of what occurs much more than we will.

We don't know at this point if this week's 'heat spell' is just the beginning of summer and if we'll be insanely hot for the next 10 or 12 weeks, or if it is just a hot spell and maybe next week we'll be a little cooler. Time will tell. I loved, loved, loved last week with lows in the 50s and highs in the 80s but knew it wouldn't last long.

I hope we get some more cool weather so we can get good fruit set for a while longer before the heat arrives to stay.

It would be okay if we never hit 100 degrees a single time this summer, but summers like that are few and far between.

I keep an eye on the Day 8-14 outlook. At the present time, it doesn't off us much hope for a nice little mid-June cool spell.

Dawn

Here is a link that might be useful: CPC 8-14 Day Temperature Outlook

Sheila,

I think that if you want to try that forumla on one or teo plants and see what happens that you should. What have you got to lose, right?

I think i kinda hijacked your thread so im turning it back over to you.

I think vegetable gardening, or any kind of gardening for that matter, is just trial and error. We all have to find what works for us in our unique little neck of the woods. Because in Oklahoma, you drive 50 miles amd everything is totally different.

So, if you do try it and it works, please let us know?

Emma

Sheila,

I think that if you want to try that forumla on one or teo plants and see what happens that you should. What have you got to lose, right?

I think i kinda hijacked your thread so im turning it back over to you.

I think vegetable gardening, or any kind of gardening for that matter, is just trial and error. We all have to find what works for us in our unique little neck of the woods. Because in Oklahoma, you drive 50 miles amd everything is totally different.

So, if you do try it and it works, please let us know?

Emma

You are fine. I was reading and learning too. Didn't know it was mine in the first place. This is all about sharing and learning. Let the conversation go where it will.

Krista, If you weren't already crazy when you moved here, trying to garden successfully in our erratic climate just might make you crazy.

Some years we have nice weather all summer long and the tomato plants never stop setting fruit. Both 2002 and 2004 were that way, but in recent years it has been harder because of recurring extreme heat early in the season, often accompanied by drought.

Sheila, I am really cautious about using formulas found on the internet. Most of them are fine, but I have been gardening for several decades and have seen them used for years....long before we had an internet....so a lot of the time I look at those formulas and know from experience they are not harmful if used as directed.

The issue is that people can post any recipe or formula and make any claim, and we are just taking their word for it, so to speak.

I always ask myself "does this make sense based on what I know about gardening?". If a formula doesn't make sense, then I feel like I would not use it. This is one of those formulas that doesn't make sense as a bloom booster, since plants need extra phosphorus to encourage them to bloom and this formula doesn't contain phosphorus. Does it make sense as a relatively cheap source of nitrogen? Sure it does, but nitrogen gives you more foliage, not more flowers. Does it make sense as a plant tonic that contributes to overall good plant health? Probably. So, to the extent that healthy plants in good soil produce better than unhealthy plants in poor soil, there probably is some way in which it is helpful in that sense. However, even the happiest and healthiest plants in great soil cannot override the effect of high temperatures and high humidity when it comes to tomato fruit set.

Also, as a final note: news travels fast on the internet. If this formula works as well as the website claims, somebody would 'steal' the idea and produce the formula in a concentrate and sell it as a bloom booster. If that hasn't happened, there is a reason why.

I'm not saying "use it" or "don't use it". I'm saying that IMHO it isn't a bloom booster, per se, it is a plant tonic.

Dawn