Question
I live in LasVegas,Nevada. I just bought 1 tomato plant, 3 putunias, 1 dahlia only about 2 weeks ago and 2 days ago i noticed my tomato plant started to droop and look its going to die not only that but the 4 flowers  a couple feet north from it started drooping too but the two old dahlias +tree west of the 4 flowers look so bright and healthy. Why is that , do i have to throw away my 5 new plant like it said aboute one tomato disease i read on the internet.please help me solve this problem.
Thank you

Answer
Michelle, it all depends on whether or not the plant has actually contracted a disease. If so, you should discard the plants to prevent the disease from spreading.

Most tomato diseases are soilborne, meaning the spores live and spread in the soil. There are many disease resistant hybrids on the market today that are not susceptible. The older varieties, often referred to as heirlooms, are highly susceptible. The same is true for the flowers, which would explain why one variety is doing poorly while the other is thriving. Different diseases affect certain plants but not others.

My best advice would be to take a 6" portion of a stem along with an 8 oz. soil sample to your local garden center or nursery and have them test it for disease. You can also talk to them about which varieties they sell that are resistant hybrids.

If, however, it is determined that your soil is infected, you should not plant in that area for several months. You can also solarize the soil by placing 3 mil black plastic over the area to kill off the spores.

Given your location, it is still early enough to purchase new seedlings and try again. The decision is yours, but I would start with the soil test and proceed based on the test results.

I hope this answered your question. Please write again if I can ever be of assistance.

Regards,

Mike