HelpfulGardener.com

Hello dear veg growers,

I'm house sitting for someone and in charge with taking care of the tomato plants. The plants are in big wooden beds on the top floor of the house with plenty of sunlight, I water them every 2 days, about 2L for each plant. The bad news is that for the last few days the leaves started turning yellow (picture attached). I've looked online and it can seems to be from over/under watering, or watering at the wrong time of day.

Are they going to die? Any advice on how to stabilise them?

Thank you in advance

Cip

It looks like the plant is lacking in nutrients, in this case most likely nitrogen, but a balance of nutrients as well. Raised beds, even with the right amount of water, will eventually flush out all the nutrients. Nutrients need to be replaced on a regular basis. Every week or ten days water with a liquid plant food. Early in the season when you want vine growth use a plant food with a higher nitrogen content (25-10-10 or close to that). As the plants begin to reproduce, switch over to a plant food with higher P and K content (8-25-25 or in that range). That fertilizer is called Bloom Booster or something like that. P and K will promote blossoming and fruit production. Nitrogen will promote green plant growth. Nitrogen late in the year will produce big bushy green plants but at the expense of flowers and fruit.

Short answer: your tomatoes are starving, give them some food. The water to nutrient ratio is out of whack. Cut back on the water to the equivalent of about an inch per week; perhaps 2L every two days is OK, but every third or fourth time add plant food.

I am not opposed to commercial plant food that can be dissolved in water but there are plant foods that are "organic" that some say works. In this case, feed the plants now.

Actually, I think there may be more than a nutrient deficiency. it may also have a fungal disease. Unless this is a heat tolerant tomato, it may not produce any fruit if the temperature is in the 90's.