Growing San Marzano Tomatoes in Kratky Hydroponics – Update: Week 9

I think my San Marzano tomatoes are one of our most highly anticipated crops, and also probably the most difficult to grow so far. Last time I posted I mentioned how they had just started flowering, and fruit was beginning to develop, as well as how we were fighting an edema issue.

The tomato bushes are now massive – actual bushes. I cant even get a proper photo of the entire plant in my grow room; the camera doesn’t have a wide enough lens.

Can you believe that I cut off a whole armload of branches off this plant every couple days?! Its insane just how fast they grow new leaves.

Fighting Blossom Drop

San Marzano Tomato 9 Weeks Old, Grown In Kratky Hydroponics
San Marzano Tomato 9 Weeks Old, Grown In Kratky Hydroponics

The tomato is still flowering, a lot. The biggest issue is I have blossom drop. There are a couple reasons for blossom drop such as incorrect temperature and humidity, or that they are not pollinating correctly.

I have checked my temperature, and the grow room is sitting in the ideal range. So I suspect that perhaps the flowers aren’t pollinating as well. I did get sick and stop using the electric toothbrush method as often, so in the future I am going to be a bit more precise in application – vibrate those leaves until you can see the pollen dust emerging from the flower heads.

Fruiting

San Marzano Tomato 9 Weeks Old, Grown In Kratky Hydroponics
San Marzano Tomato 9 Weeks Old, Grown In Kratky Hydroponics

In the last post we had the subtle-hints of fruit emerging. Well it’s safe to say that they have emerged!

We have about 14 tomatoes growing so far. Not as many as I had hoped for, but as mentioned above we had an issue with blossom drop. There are plenty of flowers on the plant with many more emerging regularly, so hopefully we will be getting more fruit over the coming weeks.

Growing San Marzano Tomatoes in Kratky Hydroponics – Update: Week 6

I just realised that I forgot to write a post for last week, oops. Sorry about that. Guess the jump of growth between the last post and this one is going to be significant. This post is going to be big (not just plant growth), but because I discuss edema, flowers and fruiting too.

Lets look back at week 4 growth:

San Marzano Tomato 1 Month, In Kratky Hydroponics
San Marzano Tomato 1 Month, In Kratky Hydroponics

I was so proud of how big they were growing… and how fast – each day seemed to produce another branch, another leaf, or another inch or two of height… little did I know that the plants would keep growing at such a speed, even two weeks later. I have created a monster; a gorgeous, hopefully soon to eat yummy, monster:

San Marzano Tomato 6 Weeks Old, Grown In Kratky Hydroponics
San Marzano Tomato 6 Weeks Old, Grown In Kratky Hydroponics

Its getting huge! We have two of the trellis supports already installed, and tonight I will be putting in the third. Thats a trellis each week…

The Curious Case of Edema

Would you believe that I have actually been cutting branches off? We’ve actually been having a problem with how fast this plant is growing. So fast that it’s actually becoming a serious problem and risk, for the plant itself.

Edema on San Marzano Tomato Plant Leaves
Edema on San Marzano Tomato Plant Leaves

See those little green spots on the tomato leaves? That’s edema. Its what happens when the plant is absorbing too much liquid… Is that even possible in a hydroponic system? Yeah it is. Edema causes the cellular structure on the leaves to swell up as they absorb moere and more liquid, to the point that they will rupture, often killing that leaf. Often you will also see crusty spots on the leaves from dried sap and water.

In mild cases its not usually an issue, but more and more of our tomato branches were becoming effected. It tends to effect the lower branches or leaves first, slowly effecting more of the plant if the environment remains unchanged.

There are a couple reasons why it can happen:

  • There isn’t enough airflow around the plant and the plant isn’t transpiring enough (sort of like you getting hot and sweaty without a cool wind). This can also happen if the plant leaves is too dense and thick, restricting airflow around inner branches. This is the most common reason.
  • The nutrients are unbalanced; the plant is sucking up too much liquid to try and get enough of one or more nutrients.
  • The water is too warm whilst the leaves are cooler, causing the plant to activate drinking mode. Sort of like when a plant is growing in a hot region – when it rains the upper plant becomes cool and signals to the roots that fresh water is being supplied.

I will write a blog post covering edema bit more and ways to resolve this. It affects all plants, not just tomatoes.

In our situation, the foliage was becoming too dense. The constant but small airflow that we had in the room wasn’t reaching the inner branches and leaves, so the plant wasn’t able to lose the excess liquids through sweating.

Over Dense Foliage on San Marzano Tomato, Week 6 Growth in Kratky Hydroponics
Over Dense Foliage on San Marzano Tomato, Week 6 Growth in Kratky Hydroponics

For now our solution was to maintain a slightly more average temperature in the grow room rather than cooler at night and warmer during the day. We are still researching the ideal fan for our grow room as some people have had issues with the common oscillating fans causing leaf burn due to overexposure of wind.

Fruitful Endeavours

Flowers on San Marzano Tomatoes at 6 Weeks, Grown In Kratky Hydroponics
Flowers on San Marzano Tomatoes at 6 Weeks, Grown In Kratky Hydroponics

It’s not all bad news; our “hard work” is paying off. The tomato plant is only 6 weeks old, and yet we have been getting flowers now for nearly two weeks!

Flowers on San Marzano Tomatoes at 6 Weeks, Grown In Kratky Hydroponics
Flowers on San Marzano Tomatoes at 6 Weeks, Grown In Kratky Hydroponics

San Marzano are an indeterminate tomato plant variety, meaning they will continuous flower, fruit and grow indefinitely as long as the environment is ideal. So it makes sense that not all the flowers are opening at once. I did a count of the flower buds that I could see – both opened and unopened. There was over 35 flower buds!

Flowers on San Marzano Tomatoes at 6 Weeks, Grown In Kratky Hydroponics
Flowers on San Marzano Tomatoes at 6 Weeks, Grown In Kratky Hydroponics

The average San Marzano tomato weighs around 120-140grams (4.2-5oz). Assuming all 35 flowers produce tomatoes, thats a minimum of 4.2kg (9.2lbs) of tomatoes! I’m so glad that I have bought some canning equipment so I can bottle up these delicious tomatoes.

Have you preserved your home-grown or store bought tomatoes? Whats your favourite way to use tomatoes? Mine is definitely pizza sauce. Let me know in the comments below.

Growing San Marzano Tomatoes in Kratky Hydroponics – Update: Month 1

Its been a month now since I planted my San Marzano Tomato seeds, and I am still in awe! I honestly can’t wrap my head around how fast these tomatoes are growing. I expected like one or two leaves a week, not one or two leaves growing every single day! Maybe all tomatoes grow this fast… I’m a first time grower and I am honestly hooked.

First, lets see how they have grown over the last few weeks:

And now, be amazed:

San Marzano Tomato 1 Month, In Kratky Hydroponics
San Marzano Tomato 1 Month, In Kratky Hydroponics

They have doubled their size in one week! I said they were growing fast, right? One of the seedlings (one on the left in photo above) was a little slow in recovery after transplanting, so his growth is a little slower than his brother. Perhaps he experienced a bit more shock when transplanting.

San Marzano Tomato 1 Month, In Kratky Hydroponics
San Marzano Tomato 1 Month, In Kratky Hydroponics

I’m not going to even bother counting how many leaves the bigger of the two has now. Last week he had nine branches, and I as already impressed. He grows new branches so fast that I wouldn’t be surprised that by the time I finish counting there would be another emerging.

San Marzano Tomato 1 Month, In Kratky Hydroponics
San Marzano Tomato 1 Month, In Kratky Hydroponics

Once a brach seems to get old enough, new smaller leaves and branches start to emerge from those.

Here is a close up of some of the newer growth. I think this growth has emerged since last night.

San Marzano Tomato 1 Month, In Kratky Hydroponics
San Marzano Tomato 1 Month, In Kratky Hydroponics

The growth is just impressive. We’d be in trouble if tomatoes became sentient and tried to take over the world.

San Marzano Tomato 1 Month, In Kratky Hydroponics
San Marzano Tomato 1 Month, In Kratky Hydroponics

I can safely say that he has doubled his size in just one week! He is now 12 inches, or 30cm, tall. Last week he was only 5 inches, or 12cm, high! It seems that the more leaves he grows, the faster he grows. With 6 inches of growth in one week, I am super excited to see how much he grows in the coming week.

Have you grown tomatoes before? Do they honestly grow this fast, or is he growing faster in the hydroponics? Have you any tomato growing tips to share with a first-time grower?

Growing San Marzano Tomatoes in Kratky Hydroponics – Update: Week 3

I wouldn’t have believed it a month ago when you said I could grow tomatoes so easily in Kuwait’s hot desert weather; but here I am, just growing tomatoes. Of course I cheated a little by growing them inside the house, in a climate controlled area… and then I removed the soil and decided to grow them hydroponically.

And they are still growing!

My little plant babies are now three weeks old, and wow have they grown. This was them only one week ago:

Their stems had just started to turn brownish tinged close to the cloning collars. They both also had two new branches.

And this is them now, at three weeks old:

I just can’t believe how fast they are growing. I can turn my grow lights off at night, then when I re-enter in the morning they have grown an entire branch! No joking, I have seen an entire baby branch just pop up in the space of a few hours.

I have preemptively placed their first trellis support bars. Since we are using custom painted Ikea Ivar cabinets to hold our plants, we bought the bottle rack as a DIY trellis. This provides some basic support for the plants, and lets me tie them in place. We can also easily raise or lower the bottle rack as needed, and even add more as the tomatoes grow in height.

San Marzano Tomato Week 3, In Kratky Hydroponics
San Marzano Tomato Week 3, In Kratky Hydroponics

This is the weaker of the two tomatoes; he isn’t growing as fast. He now has four branches, two of which are fairly large. I noticed that once the dominate grower had put out one or two smaller branches, he had substantial increase in growth speed. I expect this one would probably grow much faster in the coming week.

The dominate grower is outpacing him pretty fast; he has a total of nine little branches all emerging. He’s also about 2″ (5cm) taller than his sibling. His centre branch is just touching the trellis bars, so hopefully in the next few days he will be resting against it and can be supported with the tie.

San Marzano Tomato Week 3, In Kratky Hydroponics
San Marzano Tomato Week 3, In Kratky Hydroponics

Both tomato plants seem to be developing some good root structures. I couldn’t lift the buckets out too high as the trellis bars are now in the way, but you can see the roots extend much further down into the bucket and nutrient water. The roots are nice and white, which is a sign of plant health when it comes to hydroponics.

San Marzano Tomato Week 3, In Kratky Hydroponics
San Marzano Tomato Week 3, In Kratky Hydroponics

Have you grown tomatoes hydroponically, or maybe traditionally in soil? Do you have any tips to share with a first-time grower?

Growing San Marzano Tomatoes in Kratky Hydroponics – Update: Week 2

One week ago I transplanted San Marzano tomatoes into a Kratky hydroponic container, and we were left wondering if they survived. Here is it in Week 1:

San Marzano Transplanted into Kratky, Week 1
San Marzano Transplanted into Kratky, Week 1

I’m glad to say that not only did they survive, they have started growing wonderfully!

San Marzano Tomato Seedling Week 2, In Kratky Hydrponics
San Marzano Tomato Seedling Week 2, In Kratky Hydrponics

The two tiny specks of leaves became much larger, and we now have four to five tiny new leaves beginning to grow on each section. The original leaves have definitely turned into stems, and hopefully they will eventually become branches.

San Marzano Tomato Seedling Week 2, In Kratky Hydrponics
San Marzano Tomato Seedling Week 2, In Kratky Hydrponics

The trunk of the tomato (can it be called a trunk yet?) is about three times the thickness than when I transplanted it. The fine fuzz on it has also thickened up and become much more apparent. I don’t know enough about botany to explain what this section does – if you know please let me know in the comments!

San Marzano Tomato Seedling Week 2, In Kratky Hydroponics
San Marzano Tomato Seedling Week 2, In Kratky Hydroponics

I’m not brave enough to lift the lid and look under. The water level was filled right to the brim of the container, and I mean right to the point of overflowing. I’m worried that if I lift it I will not only introduce light to the system, I may disturb the seedling as well. Maybe next week we can check out if there is growth.

Have you grown any tomatoes in hydroponics? I’d love to know your success (and failure) stories.

Transplanting San Marzano Tomatoes into Kratky Hydroponics

So far in my hydroponic journey I have been starting my seeds in my Aerogarden Bounty; it has the highest rate of success. There is just something this machine does better than I can, which is also a reason why I recommend anyone interested in hydroponics without the scary setup look at the Aerogarden product range.

On the 1st August 2019 I planted some San Marzano tomato seeds in my Aerogarden. It’s been a week (a bit longer by the time I got around to writing this article, but photos taken on date) and it’s time to transplant my tomatoes into their final home. Exciting!

When I previously transplanted some lettuce between the Aerogarden and Kratky setup, it didn’t go as well as I hoped: my poor plants suffered a lot of shock. I since learnt that I had let the roots get too large, and the transplanting process really hurt the plants (by ripping the roots right off!).

After learning from all my recent plant murder attempts, I am transplanting the tomatoes the moment the roots emerged; one week after planting the seedlings!

Here are the tomatoes just prior to transplanting. The seedling wearing his seed pod as a hat is so cute!

My kratky container is the Klämtare Box With Lid from Ikea. It’s a great option as the plastic they use is food-safe. It’s also large enough for two tomato plants.

I used a 3″ hole saw to drill into the lid, since I was using a 3″ net cup. You could always buy a hole saw kit with several sized pieces (I bought one of these kits as well). I also chose to transplant from the peat moss to a cloning collar, though this was a personal choice. Underneath the cloning collar was clay pebbles; it is recommended to add some grow medium underneath the collar in case you ever need to remove it, as it provides significant support to the plant and sudden removal could mean the plant falls over!

San Marzano Transplanted into Kratky, Week 1
San Marzano Transplanted into Kratky, Week 1

Fingers crossed that the seedlings survive now. I’ve only transplanted once or twice, and they have all survived, but taken a bit of stress in the process.

Have you transplanted tomatoes, or any other plants? Do you have any tips to share?

Growing San Marzano Tomatoes in Kratky Hydroponics – Update: Week 1

I’ve heard a lot of people online say that they have had decent success with growing tomatoes in hydroponics, so I wanted to test just how easy it was myself.

This is the growth after 1 week, planted on 1st August 2019:

I planted some seeds into Jiffy 36mm Peat Pellets. Unfortunately just after planting we discovered that our grow light was faulty! Rather than waste the seed and peat pellet, I decided I would just start a new session in my Aerogarden Bounty. Once my replacement grow light arrives I will remove from the peat moss and transplant into a cloning collar.

They began to emerge from the pellet only three days ago, with the smallest white to very pale green sprout showing. They are growing so fast as they reach for the light!

Tomato Seedling Week 1
Tomato Seedling Week 1

Strange enough the second seedling grew two sprouts. I am pretty sure I only placed one seed in each pellet.

It looks like the two sprouts merge into one stem close the soil. I don’t want to disturb the peat moss yet. If there is more than one seedling in the pot I can seperate them when I transplant; hopefully my new light will arrive soon.

Tomato Seedling Week 1
Tomato Seedling Week 1 – Look at his little seed hat!

Have you grown hydroponic tomatoes? I would love to know how well they grew for you.

Expected Grow Times of Kratky Hydroponic Plants

I’d like to figure out how fast I can expect my plants to grow. Most seed packets and websites tell you how fast seeds grow assuming you are using soil, But hydroponics can grow up to 50% faster!

I doubt very much that my first hydroponic plants will grow 50% faster, however that doesn’t mean that I couldn’t expect to start harvesting from roughly that time onwards. You rarely need to wait until the plant reaches full maturity before you can harvest; just pull off leaves as needed and let the plant keep growing. I added “Potential Maturity” to the table below, but realistically that’s when I suspect I may be able to get my first harvest.

Earlier in the week I announced that we were hoping to grow the following vegetables and fruits in our Kratky hydroponic tubs:

  • Amaranth, Red Leaf
  • Basil, Purple Petra
  • Cucumber, Lemon Cucumber
  • Lettuce, New Red Fire
  • Lettuce, Red Sails
  • Spinach, Matador
  • Spinach, Lavewa
  • Swiss Chard, Bright Lights
  • Tomato, San Marzano

All of our seeds were purchased from Sustainable Organic Q8, and appear to have been imported from Botanical Interests. You can read more about my search from seeds in the post Where to buy organic seeds in Kuwait.

Days To MaturityPotential Maturity
Amaranth, Red Leaf90-11045-60
Basil, Purple Petra45-5523-28
Cucumber, Lemon6532
Lettuce, New Red Fire5527
Lettuce, Red Sails4523
Spinach, Matador28-4814-24
Spinach, Lavewa28-4514-24
Swiss Chard, Bright Lights5226
Tomato, San Marzano80-9040-45

I’d really to have some plants growing, or even harvestable, by late September/early October. Thats approximately 50-60 days from now. We have space for 2 large plants, along with at least 3 smaller plants and maximum of 5 plants.

San Marzano Tomato Artwork, Courtesy of Botanical Interests
San Marzano Tomato Artwork, Courtesy of Botanical Interests

The San Marzano Tomatoes are planned as a permanent setup, so these will take priority in one of the largest plant spaces. This tomato plant will be approximately 5-6 feet (1.5-1.8m) in height!

Lemon Cucumber Artwork, Courtesy of Botanical Interests
Lemon Cucumber Artwork, Courtesy of Botanical Interests

Whilst not quite as large as the tomatoes, the Lemon Cucumbers will stand about 3-4 feet (0.9-1.2m) in height. This will fill my second large grow area.

There are debates online about which spinach is “better”; matador apparently grows better in many conditions, but the Lavewa looks prettier and is slightly tastier. We want to test both of these spinaches side by side. They grow at the same rate, so we will test both the Lavewa Spinach and the Matador Spinach together.

Amaranth Artwork, Courtesy of Botanical Interests
Amaranth Artwork, Courtesy of Botanical Interests

I want to stagger the harvesting of my plants; I don’t want all my fresh leaf plants to mature at the same time, and then go one to two months with little food. So I have decided that I will start the Amaranth as well for this first hydroponic growth cycle. Granted, with its growth speed, I may be able to grow two batches of spinach by the time it reaches full maturity.

If I can fit anymore plants in my grow area I will add the Swiss Chard and the New Red Fire Lettuce.

What about you?

What are you growing this season? Did you calculate how long it takes to grow? Did you have to plan around seasons and temperature outdoors? Let me know what you’re growing!

Where to buy organic seeds in Kuwait

Don’t want to read? Here’s a quick list of links:

After researching a bit, and probably jumping into the water too fast when it comes to buying products like grow lights, I have purchased some seeds to grow in my Krakty hydroponic room setup.

Buying seeds was a specific hassle in Kuwait; the very few and limited stores that sold seeds only sold the very common varieties. Think Beefsteak tomatoes; the probably most common tomato you can find at any supermarket. Since such tomatoes are so easy to buy, I want to grow something more unique.

In fact, we even found a nursery selling seeds with the giant warning label on the back: “Warning. Treated with poison. Do not consume or grow food products from these.” What?!

In the end we found a company called Sustainable Organic Q8 that seems to import from reliable producers.

They delivered within 48 hours. We have been very happy with the brand of seeds that Sustainable Organic Q8 sells; which is Botanical Interest. They contain a lot of seeds in the pack, and they so far have a really high germination rate (for me its 100%).

Update – 24th August 2019: We found another Kuwait website selling seeds called My Organic World, though the website is all in Arabic (use Chrome web browser for auto-translate to browse in English). We bought from them, and they delivered within 24 hours! Unfortunately they sold brands Sperli and Kiepenkerl which consensus online says they can be quite expensive compared to competitors. One of the packs we bought only had 5 seeds in it! Not a reflection of My Organic World, but the seed producers themselves.

Update – 31st August 2019: Another Kuwaiti website selling seeds called PlantNMore. though the website is all in Arabic (use Chrome web browser for auto-translate to browse in English). I haven’t bought from this company yet.

Do you know anywhere else in Kuwait to buy seeds? Please let us know in the comments.

How Bright Should My Hydroponic Lights Be?

In the post Do I Need Grow Lights I measured the amount of light in each of my grow rooms, hoping to figure out which room would produce the best plant growth. At the time I was hoping to not have to invest in a grow light; man was I wrong!

A Short Warning

LUX, or lumens, to determine plant growth is widely inaccurate due to the different types of lights and the wavelengths light types each produce. Plants need certain wavelengths, or colors, to grow. No matter how bright your lights are if they are missing those wavelengths then then the plants will just not grow.

This post will not consider the wavelength or colors of lights. I’m trying to keep it as simple as possible so that anyone can follow along, even without fancy gadgets like quantum meters which can easily cost US$500. Future posts will explain wavelengths in detail. Beginners Guide To Hydroponic Lighting has a list of all the posts on how to measure and set up your lights.

You need the umol’s value or the umol/s/m2: in essence umols are how bright your light is. This value is also known as “photosynthetic photon flux” or PPF. Note that PPFD is a different value, taking into account the distance from the light.

Too low of a light strength on your plants may lead them to not growing, and too high may burn or kill them.

How To Calculate Bright Your Light Is

Most people don’t have fancy tools to measure the amount of light in their homes, such as a PAR meter or a quantum meter. Thankfully, you can get free apps on your phone that measure lumens easily.

You can use the Plantekno website to convert LUX to umol/s/m2. Note: many grow lights will tell you the PPF or umol/s/m2.

Natural sunlight has a PAR value of 900-2000μMol/m2/s when directly overhead, varying with location and season. For a grow light to be effective, it will have PAR values of 500-1500 μMol/m2/s.

In comparison, I measured my kitchen window light at 250LUX or 4.6umol/s/m2. No wonder my plants kept dying! As you’ll see below, its way below the minimum light requirements for lettuce to grow.

But how bright should my light be?

Be aware that not all aspects of how much light plants need are fully researched yet : Lefsrud at McGill University has extended upon NASA research and one thing he noted was common incorrect assumptions. For example, many people consider lettuce to a shade loving plant and tomatoes to enjoy full sun. However when shone with 5000 umol’s, the tomatoes suffered whilst the lettuce showed no signs at all! The exact opposite of what was expected.

Research Gate website had several listed studies that mentioned the number of umol’s used for ideal plant growth:

Minimum umol’s Required
Lettuce100-200
Watermelon250
Tomatoes400-500

According to the company Valoya the amount of umol’s a plant needs will vary depending upon its growth stage: seedling, vegetative, flowering/fruiting. They claim that lettuce needs approximately 80 umols during seedling, 150 for vegetative stage and 200 when it begins to flower.

Valoya’s Comparison of umol’s for Lettuce Growth

I found a really great article from the Department of Horticulture and Crop Science: this PDF covers a huge variety of plants, and the recommended lighting and hours lit for each of the growth stages, and what level nutrient solution is ideal.

Here is a small sampling of some common plants and their needed light intensity (taken from above PDF link):

Lettuce

# Light HoursLight Intensity
(umols)
Propagation12-20150-250
Vegative12-20250-450
Flowering12-20250-450

Strawberries

# Light HoursLight Intensity
(umols)
Propagation12-20250-450
Vegative12-20 250-450
Flowering<12 250-450
Fruiting12-20 250-450

Tomatoes

# Light HoursLight Intensity
(umols)
Propagation12-20250-450
Vegative12-20450-700
Flowering12-20 450-700
Fruiting12-20 450-700

Where To From Here?

Notice how I mentioned the number of light hours needed for plants in the tables above? Different plants need different lengths of light exposure. You can’t just leave your grow light on 24/7! The next post in this series is How Long Should My Hydroponic Lights Be On? It explores Daily Light Integral or DLI, the measurement that takes into account growth light strength x time its on for optimal growth.

Beginners Guide To Hydroponic Lighting has a list of all our posts on lighting, written to help a beginner learn the basics and get started right through to more advanced topics.

Do I Need Grow Lights? is the previous step in this series. Not everyone has a PAR meter or Quantum meter; they can be expensive. So how else can you measure the light your room gets? Whilst not very accurate, this can give you an idea of how bright your rooms are; helpful in finding out if you need to invest in a grow lamp!

How Long Should My Grow Lights Be On For Hydroponics? is the next step in this series. You know how bright your light should be, but how long should it shine? Plants need time to sleep and rest too, just like you. This post explores how to determine how many hours of light your plant needs (it can vary a little depending upon how bright your light is).