Help with my sad hydroponic tomato? - Ask Extension
Hi there,
I decided to try a hydroponics garden this year and am hoping one of you awesome Master Gardeners might be able to help me figure out why...
Knowledgebase
Help with my sad hydroponic tomato? #678210
Asked December 12, 2020, 3:31 PM EST
Hi there,
I decided to try a hydroponics garden this year and am hoping one of you awesome Master Gardeners might be able to help me figure out why my tomato plant is so unhappy.
I have my plants in a deep water culture set up with each in their own 5 gallon bucket. My cherry tomato is getting general hydroponics trio weekly (right now along the "mild growth" recommendations on the label) along with CalMag for added calcium and magnesium and Hydroguard - and I'm changing out the water completely every two weeks. I've been trying to keep the Ph right around 6, and I believe that my plants are sufficiently far from my light source.
New foliage emerges looking green and healthy, but then the leaves yellow and eventually fry out, as shown in the picture (and you can see that it's lost leaves along a lot of its stem). I had two other full size tomatoes in the same set up and lost both of those to this same problem about two weeks ago. Both types of tomatoes were recommended for hyrdo by Johnny's Seeds. The other really noticeable thing is that my tomato has a super tiny root system compared to when my other plants were at this stage in their growth. It really only has one root that has made it through the net pot, the rest are just barely at the edge.
My eggplants seem to be having a somewhat similar problem, but is growing and flowering despite it, and my peppers are incredibly happy with lots of healthy foliage and lots of little baby fruits. All of them are in the same set up and getting roughly the same treatment.
Any idea what might be going on here? I've read a bit about nutrient burn, nutrient lock out, and the temp of the water in the reservoir, but just can't quite figure out how to make my little tomato thrive and realize my dream of home grown winter tomatoes!
Hennepin County Minnesota
Expert Response
Hello! Happy to help.
It took a bit of time to get some help from the U of MN Extension agriculture expert but I think it was worth the wait since you know much more about hydroponics that I do. Her recommendations cover a few minor adjustments and you should be on your way. Here's her recommendations:
The first thing I'd say is that 6 is a little too low for pH. 6.2 - 6.5 is ideal for hydroponic tomatoes, and while 0.2 seems very minor, it can make a big difference in hydroponic systems. The tomato and eggplants both look like they would benefit from a little bit more nitrogen. Adjusting the pH might help make the N you're adding more available, but
I would try increasing it a bit. Finally, the tomatoes look light stressed. They do require more light than peppers - ideal is 230 μmol/s.m² compared with more like 170-180 in peppers. If you're able to increase your light level, I think that should help with the leginess.
It took a bit of time to get some help from the U of MN Extension agriculture expert but I think it was worth the wait since you know much more about hydroponics that I do. Her recommendations cover a few minor adjustments and you should be on your way. Here's her recommendations:
The first thing I'd say is that 6 is a little too low for pH. 6.2 - 6.5 is ideal for hydroponic tomatoes, and while 0.2 seems very minor, it can make a big difference in hydroponic systems. The tomato and eggplants both look like they would benefit from a little bit more nitrogen. Adjusting the pH might help make the N you're adding more available, but
I would try increasing it a bit. Finally, the tomatoes look light stressed. They do require more light than peppers - ideal is 230 μmol/s.m² compared with more like 170-180 in peppers. If you're able to increase your light level, I think that should help with the leginess.
I hope this information helps.
This is so helpful- many thanks to you and your colleague! I’ve made all of these adjustments and hopefully my tomato will be back on the right track, or at least if I start another that one can get off on the right foot.
Do you or your colleague happen to know if there are any local home hydroponic clubs or societies? I’m finding hydroponics to be harder to get the hang of than regular outdoor gardening and would love to be in conversation with other folks who are learning, too.
Thanks again and happy holidays!!
On Sat, Dec 19, 2020 at 7:15 AM Ask Extension <personal data hidden>> wrote:
Hello!
I'm afraid I don't know of any such group but the U of MN Extension Master Gardeners are constantly creating new programs where gardening techniques are taught. I'd check out the Hennepin County Master Gardener website for notifications of up coming classes. You might also check out classes offered at the University of Minnesota Landscape Arboretum.
Good-luck!
I'm afraid I don't know of any such group but the U of MN Extension Master Gardeners are constantly creating new programs where gardening techniques are taught. I'd check out the Hennepin County Master Gardener website for notifications of up coming classes. You might also check out classes offered at the University of Minnesota Landscape Arboretum.
Good-luck!
