My tomato plant is over 6 feet tall but has no new blossoms - since you all taught me about squash blossoms and their need for pollination - are tomatoes the same? I've googled it a bit but my tomatoes are still the same two that had blossoms when I bought it - they are green and fairly large but started to have marks at the top. I put it outside for a bit (screen lanai is where it has lived) yesterday and I let a bee come into the lanai - I wonder if I need to cut off some of the height? help me. (I did add a liquid fertilizer as you all suggested).
Are they determinate or indeterminate tomato varieties, your plans? If they are Indeterminates, have you been pruning them and taking the suckers out? ( can google)
Are they in containers? The composition of the soil can be what's wrong. Too much Nitrogen in your soil ( and in that liquid fertilizer) will make the plant stick all its energy into plant growth and it will make a huge plant, with barely any flowers or fruit, which is not what you want. All fertilizers have the level of Nitrogen, Phosphorus and Potassium listed in that order on the container.
Start fertilizing with a fertilizer where your Phosphorus and Potassium numbers are much higher than the nitrogen number, this may help a lot already. maybe a 5 -15-15 one or 5-20-20 if you can find it.
Also, temperature and sun. not sure where you are located, generally 6-8 hours of sunshine are best. When it gets too hot, temps above 95 consistently, most plants, including tomatoes, green beans etc, drop their blossoms out of self preservation. They stop setting fruit and stick all their energy in surviving the heat. When it cools off they may set blossom again.
One more thought I had: if you bought the plants at a nursery or garden center, still small and already with blossoms, this may be the problem. Generally you want small plants that do not have blossoms yet, or they may, even after transplanting, stay stunted and not bear much fruit. Or if they have blossoms too early, keep pinching them out until the plant has had a chance to stick its energy into grow a good big root ball first.
Try pruning, temp or sun changes if possible, and if you already fertilized with high Nitrogen, switch to a fertilizer with zero Nitrogen in it , and just potassium, phosphorus, calcium. i buy Gypsum powder on line and add it to soil when transplanting or mix good scoops into my watering can and water the roots directly with that straight calcium to prevent blossom end rot.
Just some thoughts for you, from what I've learned in 10 years of growing tomatoes.
