Hi Everyone! In this video, I'll be trying to grow rosemary in a hydroponic system. I've tried
this once on the channel before- we made some good progress, but eventually lost the plant,
so I'm trying again. I'll be starting this rosemary journey in the same way I did before,
with a package of rosemary cuttings from the local supermarket. There are a few small stem cuttings
in here which should be able to propagate. I've had a bit of difficulty getting rosemary cuttings
to root, but seem to have the best results when using bigger cuttings with thicker stems. I'm
going to give these stems a fresh cut, clear lower leaves off of those stems and put them into a jar,
submerged about an inch or so in water, so that they can propagate. 15 days later, one of our
cuttings had multiple roots emerging. This was the only cutting that would grow roots. Again,
I think the issue being that my cuttings were too small. By day 21 these roots were really getting
long and beginning to branch out. I moved the plant into a net cup at this point and supported
it with clay pebbles. The plant was given its own reservoir, with water and nutrients inside.
The plant would grow pretty quickly from here. The primary stem of our cutting was clipped at the
top, so the plant was putting its energy into four separate stems. Each of these stems had a bunch
of new leaf growth and looked healthy. I began pruning the plant, to remove young branch sites
emerging in the core of the plant. I want to encourage those four main stems to space out a bit
before they branch out in all directions. Eight weeks in, our plant was still looking good and the
root system was a nice white color. I did however find a few leaves that I had pruned fell into the
reservoir and now had mold growing on them. I gave these areas of the root system a quick bath
in hydrogen peroxide to sterilize it, I rinsed the roots and moved the plant into a clean reservoir.
The plant would rebound nicely from that and resumed growing. I was continuing to
prune secondary branches as they emerged. Around week 13, I would begin some low stress training,
using pipe cleaners to help the plant spread out. I was refilling the reservoir as necessary,
and generally the plant seemed to be doing good. As we entered week 16, things started to turn for
the worse. We were still seeing good leaf growth up top, but our root health was beginning to fade.
Our bright white roots are turning into a dull dead-ish looking gray- which doesn't seem great.
The last rosemary plantIi tried to grow in hydroponics died off at about this same time.
Before leaving on a vacation I gave that plant a nice full reservoir so it would have plenty to
drink while I was gone. I would return to find a completely dead rosemary plant, with black,
rotted roots. This had me anxious about my current plant! As it turns out, rosemary is most happy in
a Mediterranean climate- known for long, dry summers. Wikipedia tells me that rosemary is
drought tolerant and not able to withstand water logging. Hydroponic systems are the opposite of
dry- even worse, I have this plant growing in an aeration-free reservoir, 'Kratky' style,
probably making it even harder for this plant. To try and compensate for this, I left the reservoir
mostly empty- pouring in small bits of nutrient solution at a time and also trying to wet the root
system as I did so. The reservoir was never more than 25% full. This new watering strategy seemed
to work at first. We had some new white roots emerge and the leaf growth up top was stronger
than ever. By week 20 though, this rosemary had seen enough. The stems weakened and curled over,
leaves lost their vigor and again our root systems became a solid black. A sad end, but at least to
me, this cemented some of the thoughts and lessons I had from the first attempt. I was afraid I had
accidentally drowned that first plant, filling my reservoir too high before leaving the plant alone.
Now, I see that rosemary will effectively drown even in a small amount of water.
I believe rosemary just doesn't like this Kratky hydroponic setup. Maybe aeration
would help to unlock the growth potential of these plants? I'm not sure. If anyone has
hydroponic rosemary knowledge, I would love to hear it! Please drop us a note in the comments.
I'm not sure that it's even possible to grow these plants in a hydroponic system and I'd recommend
sticking to soil for all of your rosemary grows. Thanks for watching and Happy Harvesting!