Tomato small leaf - Ask Extension
Hi,
I grow tomatoes every year. Last year I planted them in a different place, about 50 feet away from the usual place. I planted Zucchini and Fava i...
Knowledgebase
Tomato small leaf #877164
Asked July 14, 2024, 2:45 PM EDT
Hi,
I grow tomatoes every year. Last year I planted them in a different place, about 50 feet away from the usual place. I planted Zucchini and Fava in place of tomatoes last year. This year plants don't look healthy, although producing but not as they should. I tried to increase watering intervals from once a day to 2 and then 3 times a day but no difference. I don't use any pesticide and only use compost that I buy bulk- not bagged ones. Se attached and let me know.
Thanks.
Montgomery County Maryland
Expert Response
The first issue to mention is watering. The tomatoes could be over watered based on your description of watering 1-3x/day. If tomatoes are mulched, which they should be, they can be watered (at the base ) every 2 to 3 days at the most. Only tomatoes in containers may need water everyday. Like most plants, they should be watered when the soil a few inches down appears dry. And they should receive a drenching watering each time you do water. Frequent short watering promotes shorter roots, while less frequent, deep, longer watering will promote longer roots. If they are wilting, despite having recently been watered, there is likely another problem.
The second issue is fertilization. Have the tomatoes been fertilized? If leaves are yellowing there could be a nutrient deficiency.
And the third issue is the unusual heat and humidity we have had this summer. Many plants have been stressed from the heat and that could cause the leaves to curl up on tomato plants.
The following link should be helpful as well:
https://extension.umd.edu/resource/key-common-problems-tomatoes/
Debbie
The second issue is fertilization. Have the tomatoes been fertilized? If leaves are yellowing there could be a nutrient deficiency.
And the third issue is the unusual heat and humidity we have had this summer. Many plants have been stressed from the heat and that could cause the leaves to curl up on tomato plants.
The following link should be helpful as well:
https://extension.umd.edu/resource/key-common-problems-tomatoes/
Debbie
Thanks for explanation. I always use plastic mulch (plastic sheeting) with soaking hose under plastic for my tomatoes. I water them for 30 minutes around 0500 everyday. To make sure that I am not over watering (as you explained), I will remove some of the plastic to see how dry/wet the soil is.
I don't use fertilizers, I always use compost only. So far only 3 of the plants that are next to each other are yellow and are losing leaf, looks like they are dying.
Please look at the pictures again especially the "Top part" of the plants where leaf are small and some are completely cut, I will check again more closely for caterpillars, so far I didn't see any.
Please advise.
On 07/15/2024 12:23 PM EDT Ask Extension <<personal data hidden>> wrote:
We don't see any hornworm caterpillars in the photos. Missing leaves could be due to undetected hornworms that are already gone (eaten or finished maturing and left), though looking for frass (dung pellets) on the ground beneath the plants can be an easy way to reveal their presence when the caterpillar itself blends-in too well.
If you have had luck with nothing but compost in years past, that's good news, but usually compost does not provide enough nutrients on its own, especially nitrogen. Water-soluble forms of nitrogen also leach out of the soil readily the more it's watered, and nitrogen is the nutrient plants need in the greatest quantity. Heat buildup under the landscape fabric / plastic mulch, especially during this year's abnormally hot periods, might be worsening plant stress. Growth can slow or stall during period of high heat, as it can damage chlorophyll and plant tissues.
As Debbie mentioned, a half-hour soak every day might be more than the plants need, especially if they are not in as much active growth during this heat wave. (Plants close leaf pores when heat or drought stressed, and this also slows water loss from the leaves, which means water isn't moving up from the roots as much.) How soaked the ground gets from watering depends on how much water the soaker hose is depositing, but if it's wetting the soil down to a depth of several inches each time, its use can be spaced-out, probably by several days since the plastic is inhibiting evaporation. (If it's more of a pore-less plastic than a porous landscape fabric, it also might be reducing oxygen levels for the roots below.) Beneficial soil microbes that turn organic nutrients from sources like compost into forms plants can absorb need to live in oxygen-rich environments, so if they become oxygen-starved, their activity might wane.
We do not see any indications that a disease or pest (other than potentially hornworms) is causing the plants to struggle.
Miri
If you have had luck with nothing but compost in years past, that's good news, but usually compost does not provide enough nutrients on its own, especially nitrogen. Water-soluble forms of nitrogen also leach out of the soil readily the more it's watered, and nitrogen is the nutrient plants need in the greatest quantity. Heat buildup under the landscape fabric / plastic mulch, especially during this year's abnormally hot periods, might be worsening plant stress. Growth can slow or stall during period of high heat, as it can damage chlorophyll and plant tissues.
As Debbie mentioned, a half-hour soak every day might be more than the plants need, especially if they are not in as much active growth during this heat wave. (Plants close leaf pores when heat or drought stressed, and this also slows water loss from the leaves, which means water isn't moving up from the roots as much.) How soaked the ground gets from watering depends on how much water the soaker hose is depositing, but if it's wetting the soil down to a depth of several inches each time, its use can be spaced-out, probably by several days since the plastic is inhibiting evaporation. (If it's more of a pore-less plastic than a porous landscape fabric, it also might be reducing oxygen levels for the roots below.) Beneficial soil microbes that turn organic nutrients from sources like compost into forms plants can absorb need to live in oxygen-rich environments, so if they become oxygen-starved, their activity might wane.
We do not see any indications that a disease or pest (other than potentially hornworms) is causing the plants to struggle.
Miri
