Tomato Leaf Curl Epiphany

July 3, 2016 by Tilly 12 Comments

So in order to try to help resolve the tomato leaf curl situation in the garden, I ended up investing in a moisture meter.

I say “investing” but it only cost about $6 from Wal-Mart.  This little gizmo is obviously at the low-end of the spectrum on moisture meters, but I figured for a start it would be fine.

When I took it out of the package I immediately started testing it on the house plants. Everything came out on the dry side. I watered and measured the moisture again and this time the level was right in the middle. Perfect.

Heading outside I started with the tomatoes planted in the big garden. We’d had rain the night before so I figured there should be some reading. I was right. It was right in the middle.

Then to the side of the house where the tomatoes are planted in small boxes with either mulch or rock around them as well as a planter top marking the base of the plant and giving me a guide for watering. These too showed they were moist enough.

The meter is right in the middle, where it should be.

On further inspection though I noticed that the planter tops that were around the bases of the three plants with severe leaf curl were smaller. This meant that when I watered them, they would not get as much water as the other plants. Could this be why these are pretty much the only plants in the ground that are affected?

Small planter top.

Larger planter top.

I tested my theory last night when the moisture meter indicated the plants were dry enough for watering. When I watered the three plants with the smaller planter tops, I watered them twice, filling the space around the roots twice with water.

When I went out to the tomatoes this evening, 24 hours later, already some of the curly leaves are uncurling!

Success!? Well, if there’s one thing I’ve learned in gardening — Don’t get too excited. Who knows if what I did made a difference. It could be the actual rain we got a few nights ago, it could be that the weather has been cooler, or what I’m really hoping for — it was me watering them twice.

Well, after noting that the tomatoes on the side of the house seemed to be doing slightly better, I headed to the tomatoes planted in pots. These too have been fighting the leaf curl a lot more than the plants planted directly in the ground. With these I have been sure to water them until the water flows from the bottom of the pots. When I checked for worsening leaf curl, there was none. In fact they too seemed to be improving.

The evidence seems to support the fact that I have been under-watering, so I am going to continue watering more and using my moisture meter to gauge when I should be watering. Just looking at the soil is deceiving. This pot here looks like it’s bone dry and yet when I put the meter in the soil it comes out right in the middle. I won’t water now until tomorrow.

See how the dirt looks completely dry?

But when the moisture meter is inserted, it’s moist.

I’m not sure if anything has been resolved, but it does seem like I’m getting closer to a solution/cause for the tomato leaf curl in my garden, and for this I am — Simply Grateful.