Growing strawberries indoors using hydroponics


#1

I’ve been doing hydroponics for three years and have had a lot of success and a LOT of failures. Last year I really stepped up the game and accomplished exactly what I set out to do, which was to grow a ton of salad veggies (Photo1, Photo2).

This year I hope to use the same system for growing strawberries. I grew Mara Des Bois (for its flavor) and
Evie 2 (for its productivity) outdoors in strawberry towers but while they appeared healthy and produced a decent crop the strawberries were extremely bland for some reason (nutrient deficiency?) and then got destroyed by SWD. About a month ago I rooted a bunch of runners as they were hanging off the mother plant in rockwool cubes wrapped in aluminum foil and have since transported them into my temporary hydroponic nursery system to grow out the roots before they get moved to the final system.

Above is what they looked like a couple days ago. If you look close you can see a couple flowers already forming and the new growth is looking healthy, although some of it is deformed from the transplant shock of going from the cold outdoors with no nutrients to 72°F root temps in highly oxygenated and because I used too strong of a nutrient solution.

I know this is an unusual way to grow fruit and I haven’t seen to many topics about hydroponics on here but I would be glad to answer any questions and post updates about my progress over this winter if there is interest in it.


#2

Time for a quick update. Lots of leaf growth, blossom and fruit productions happening now. New leaf growth appears to have a nice color and little deformation meaning that the nutrients and pH are well balanced. Lots of blossoms coming in and fast - about 6 confirmed fruit and 6 blossoms right now. For pollination I’ve been mostly just poking the blossom with my finger a bit… kind of odd but has had 100% pollination rate so far. Going to try not doing anything to a couple blossoms and seeing if the small fan I have blowing on the canopy will be sufficient for pollination.

As expected, I am having some problems with fungus gnats. I rolled out the sticky trap carpet for them to try and minimize their population growth and have some food grade diatomaceous earth on order as an offensive tactic. If that doesn’t work I’m going to use the nuclear option of mosquito bits as a microbial insecticide.

Also having some problems balancing pH. Oddly, the nutrient solution pH keeps going down which from my research and situation means that I am likely giving them too much nutrients (although I read that pH drops also happen during the transition to flowering). I’ll be transplanting to my main system soon so balancing pH will not be as much of an issue since I will be working with a much larger volume of water relative to plant volume.

For those that find this kind of thing useful here are recent growing parameters:

  • using day-neutral cultivars, no blossom removal at any time
  • air temperature is cool 64 - 68°F, humidity is around 60%
  • nutrient solution heated to 72 - 74°F
  • nutrient solution has been a pH of 5.8 - 6.4
  • nutrient solution concentration is 1.2 EC (600 PPM), above tap water
  • complete solution changes done every 2-3 weeks

#3

Moved the strawberries from the hydroponics “nursery” to their final growing area. As seen in the photo below, the strawberries are now planted in three channels which are just 8’ 4x4" Vinyl Fence Post with about 2" of nutrient solution running through them. There is a 30-40 gal storage container which has an air pump to add oxygen to the nutrient solution and a water pump to bring the nutrient solution to the other size of the channels where gravity flowing it past the roots and returns it to the storage container / reservoir.

I left a ton of space between the plants with the intent to fill it out later using the strawberry runners. The battle against fungus gnats is still ongoing although I believe the tide is turning in my favor. Blossom production is going strong but I definitely think that some manual pollination is needed as I think I’m seeing signs of failed pollination and misshapen strawberries.

The NEW-new-growth is looking fantastic but it makes me notice that the leaves that came shortly after I moved the plants into the hydroponics system have stalled in growth and look a bit deformed. I’m almost certain this was caused by early over-fertilization and unbalanced pH at some point - fortunately with the 30+ gallons of water they now grow in things much more stable.

One strawberry looks like its starting to ripen but because it’s the first flush and suffered through all the nutrient solution fluctuations I’m setting my taste expectations very low.


Grow Lights
#4

I’ve always wanted to experiment with hydroponics. I am thinking about planting some different type of plants and floating them in my farm pond next year on big sheets of styrofoam insulation. Just to see how they would grow.


#5

Quite a bit of futzing there. I guess it won’t be so bad once you get it down.

That’s why I kind of like my aero garden. It’s been pre-futzed, (in a clunky sort of way). Grows dwarf Romaine lettuce in (Breen cultivar) very well.

Wish someone would market a book-shelf/credenza system with more capability at a reasonable price.


#6

I totally agree. It’s highly experimental at this point since I’ve never grown strawberries so I don’t know what to expect. I also haven’t really found any good tutorials on the subject, most come from people doing it their first time and they never follow up on their yields which I take isn’t a good sign that their methods worked. Honestly though most of the futzing is self induced - I have to keep telling myself not to check on them every day because I won’t be able to tell the difference in growth, LOL

Glad to know you are enjoying your aero garden - my friend has successfully grown cherry tomatoes and flowers with his. If you are looking for “low-futz” hydroponics and have a sunny area in the house check out the Kratky method.

Should be an interesting experiment. Assuming there is enough nutrients in the pond I can definitely see this working.


#7

How does hydroponics work out financially? Is growing this way still cheaper than buying strawberries etc from supermarkets?

A few years ago I ran a small aquaponics set up for a class. Aquaponics is similar to hydroponics except the nutrients are supplied by fish waste. It worked fantastic, the fish thrived and were cheap to feed, but I wasn’t paying the electricity bills and have no idea how much it cost to run the pump.


#8

Not economic, like most home gardening projects. Especially if growing under lights. Still, not horrible.

My little aerogarden cranks out six-seven mini-heads of lettuce that we consume over a two week period after a six week grow period. If you grow herbs, maybe 16-17 dollars worth of fresh herbs, at any given time and of course convenience. Growing tomatoes is a novelty.

The short-run operating costs are pretty inconsequential, including electricity and reasonably priced “General Hydro” ferts. (I also sprang for a $16 total dissolved solid meter—-well worth it.). Remember, you are leaching the space heating for your dwelling that otherwise goes to waste, which mitigates things.

Then the light burns out. $82 for a new hood. Replacing the light on a homemade setup would be cheaper, but not by a whole lot. So it’s definitely a money-loser long term. On the other hand, excellent quality Romaine lettuce mid-winter is pretty nice.


#9

Yeah, I very likely spent just north of $1,000 on my setup which gives me a 2x8’ growing area with an option to add a second 2x8’ level in the future. I did invest in high efficiency LEDs (which last >10 yrs if kept cool) and custom built the light fixtures which cut down on costs a lot. In regards to electricity last I calculated it out it was about $13/month $22 per month.

In my opinion it’s not at all about saving money, the top three reasons I do indoor hydroponics are:

  1. You can 100% control the growing environment so the weather, pests and disease more or less aren’t a problem
  2. Things grow MUCH faster (about 1.5X) than outdoors
  3. Once you get things tuned in you get very reliable results with little maintenance

#10

Small progress update. Fungus gnats have been all killed off by aggressive use of sticky traps and a bit of diatomaceous earth :heavy_check_mark:. pH looks like its stabilizing and it’s getting easy to keep between 5.8 and 6.2 :heavy_check_mark:. About two dozens blossoms have formed, half look to be pollinated :heavy_check_mark:. First strawberry was harvested :heavy_check_mark:.

I didn’t take a photo of the harvested strawberry because I think I got too eager and picked it too early. Going to wait until the next flush comes in (likely a week from now) before I make any judgement. I’m also not sure which plants are Evie 2 and which are Mara Des Bois so figuring that should be interesting, haha.

Since someone asked about the costs of hydroponics I figured I would use my Kill-a-watt to see how much power I actually use. It looks like my system consumes 4.73 KWH per day, which with my electricity costs would be about $22 per month. The lights themselves are 177 watts and I run them from 5am to 7pm hours. The only other operating cost is buying the hydroponic nutrients but those are very cheap - I’m still using the ones I purchased two years ago for $35.


#11

The futzing continues as new problems arise. Major issue looks to be some kind of calcium deficiency but also an aphids and spider mites invasion.

The calcium deficiency I am judging by the fact that the leaves are distorted and deep-green with notable tip-burn on newer leaves. I’m not quite sure where its coming from as the pH is balanced, there is adequate ventilation, humidity is okay and the roots look healthy. I’ve purchased some Cal-Mag supplement and will do a foliar application as quick fix, I will then do a full nutrient change-out (I’m about due for one anyway) with the extra Cal Mag and hope that it will fix the problem.

I looked at the prior photos and it looks like I may have had a baseline of this issue since the start (deep green distorted leaves). I also had this issue back when I grew other plants like boc choi so maybe I might switch up the nutrients I use all together.

Another issue is that aphids and spider mites hitched a ride on the plants and their population has exploded since they have no predators in this isolated growing environment. I did a moderate spray of Azamax (basically chemically refined neem oil) and will follow up with another spray in a week… hopefully that takes care of it.

There was also the odd case where one plant just randomly wilted like it wasn’t getting enough water. Its roots look okay and the plants by its side are doing okay so I have no idea why it just decided to give up (sensitivity to Azamax?). I trimmed back its leaves and increased the amount of oxygen I am pumping into the nutrient solution thinking that maybe it wasn’t enough and for some reason this one plant was drowning. Its recovered a bit this morning but still… very odd.

The only positive is that there is an unbelievable amount of blossom production - probably because the plants are stressed and trying to reproduce before they die, haha. There is one partially ripe fruit that I will give a full chance to ripen and I will for sure have some notes on taste of these (mildly-misshapen) strawberries in my next update.

Lessons learned so far:

  • Before moving outdoor plants indoors you MUST give them a good soak with an insecticide
  • Start off at 1/2 the dose of nutrients and then climb up to your target over a couple weeks
  • Use sticky traps right at the start to let you know if you have any incoming pest issues
  • Start at 0.6-0.8 EC for young plants and switch to 1.2-1.5 EC total when flowering and keep pH around 6

#12

First significant fruit harvest! Picked 4 berries yesterday and see about 5-10 berries that will be ripening over the next week. Current “production” is coming from just 3 or 4 plants so I hope to get to the point where half a dozen berries are ripening every other day in 4-6 weeks.

Since I still wouldn’t consider the plants to be fully healthy I am waiting until they further develop to make any judgements on flavor or sweetness. That being said, I can already tell that they taste better than store bought berries.

Nutrient balance issues appear to be mostly resolved. In addition to doing a full nutrient solution change I applied a foliar cal-mag spray both of which have resulted in a burst of new leafy growth. One critical thing I realized this week is that I made a mistake with the original batch of nutrient solution in that the order I mixed things was wrong. This likely led to some nutrients to precipitate out of solution - such as calcium and other micro nutrients, which makes me think this is why I have been having all these nutrient balance issues. Admittedly, I made the same mistake on this batch but I intend to correct it with a partial nutrient solution change out in a week or two (since the plants are growing well right now).

The fight against aphids is ongoing but their population growth appears to have been curbed. Using an azamax + diatomaceous earth spray which appears to be effective but leaves a white residue on the leaves and may slightly stunt growth which is why I am now using it sparingly every 7 days and may further dilute the strength.

Oh and the one plant that was oddly struggling in my last post has been put out of its misery. It was continuing to dry out and I didn’t see any new growth coming even though it looked like it had healthy roots. It may have recovered given enough time but I didn’t want to risk the release of decaying matter / whatever was killing it into the nutrient solution. If I had to guess it likely was the full strength Azamax that killed it.

In regards to managing this growing setup I figured I would explain what tasks need to be done to keep things running:

  • Every 2-3 days I check the pH of the nutrient solution and adjust with an acid or base to get things back to around 6.0 pH; only takes about 5 minutes
  • Every week or so I top off the nutrient solution reservoir with regular tap water or a 1/2 strength addition of nutrient solution depending on what the EC measures at
  • Every 4-6 weeks I do a full nutrient solution change out - as in dump everything and start from scratch. You’re supposed to do it more frequently but I haven’t had a problem pushing it this long. This takes me a full hour because I also like to give a good scrubbing to anything that feels slimy or has residue on it

If I had to go on vacation for 2 weeks I suppose I could setup a secondary reservoir that would feed into the main one via a float valve. The pH might get a bit out of whack but I don’t think it would get bad enough to significantly harm to the plants - and since the pH now appears to go up at a steady rate I could just make the top-off solution slightly more acidic


#13

Very nice set Dimitri! Are you going to plant the runners.

Tony


#14

Thanks! In my next post in two weeks I’ll try to explain how I build this system for those not familiar with hydroponics.

Once I get some I’ll try to use the runners to fill in any empty space between the plants. In the future when I start from scratch I will try to use crowns/bare root plants and then soak them in dilute bleach before use… this would prevent the pest problems I am having.


#15

It may be a coincidence, but the row on the back looks healthier than the on in the front. I suspect it is lightning issue. The rows on the back and middle look brighter. Try to add a mirror hanging on the front reflecting side inside. You can remove it when you work with plants. The cheapest tall narrow mirror from Walmart will work, if you place it long side horizontally.


#16

I agree that it looks like the back row is doing noticeably better than the front. Could be because I mess around less with the plants in the back, I’ve also pruned out a lot of old growth so that might throw things off a bit.

Its not shown in the photos but I actually enclosed the whole growing area with 6 mil diamond Mylar film to focus as much light onto the plants as possible and close off the front when I’m not working on the plants (see photo below). The photos really don’t do the lights justice in showing just how blindingly bright they are.


#17

@dimitri_7a

Thanks for sharing your experience. Very informative thread.

I used to have mites problem for indoor strawberry. I did a little research, dual actions maybe a way to go. I bought one from Amz, but never had to use it (yet). I changed the culture practice, mites does not seems to the problem. This chemical probably is my last line of defense. I never be able get mites under control once it started.

Azera Gardening Dual Action Azadirachtin/Pyrethrin by PyGanic Gardening

I had this problem as well, i noticed this problem happen during

  • in DWC system, EC is too high (~2+)
  • mostly due to humidity issue (too low) ie.Vapor pressure deficit, the water evaporation was too fast, calcium not be able to transport to leaf evenly ? read more about this link

I told my little one (who is an astronaut wanna be :slight_smile: ), daddy is doing space technology, this maybe how we provide food for the long ride to Mars :smile: :smile: :smile:


#18

Mites and fungus gnats don’t seem to be too much of a problem now, its mostly aphids. I’m trying lower strength but higher application frequency (every 3 days) with Azamax until the problem (hopefully) goes away. The reason this problem persists is because I can’t really drench the plants with the way things are setup - I had a spider mite problem on my Meyer lemon and a single drench took care of the problem.

Too early to tell if the calcium deficiency is still a problem. I’m waiting another week or two until I do an update but I think things are getting better now. Humidity is around 50-55%, EC is 1.6 now. Cal-mag folair spray really seems to help.

Honestly it’s very frustrating at this point because there is an accumulation of problems from how I started things (no preventative pest measures, improper nutrient mix). It’s tempting to just order some new bare root plants and start from scratch but I think I will give these plants another couple weeks to improve. I usually terminate indoor growing in late spring but I might keep it going just to see how the plants do long-term.


#19

Small update. I decided that fighting aphids indoors is a losing battle and went with the nuclear option of using a systemic pesticide, imidacloprid (via BioAdanced Citrus and Vegetable Insect Control Concentrate). Added it at 2/3rd the recommended dose right to the nutrient reservoir and will be doing a full nutrient solution change out in a week and abstaining from eating the berries for 14 days. The aphids were spreading to my fig cuttings and I really couldn’t have this aphid breeding ground close to where I was also planning on starting my garden seeds in a few weeks.

If the systemic takes care of my aphid problem I might try growing some alpine berries in the system (seeds already started). If it doesn’t I’m going to scrap all the plants and order some new barefoot stawberries AND THOROUGHLY DRENCH THEM IN AZAMAX. I’m definitely leaning towards running this system all year… despite all the frustrations and setbacks I’ve experienced.


#20

Things are looking good! The imidacloprid completely annihilated the aphids and the only signs of pests that remain are tiny pockets of spider mites on old leaves that I will continue spot treat (or remove entirely) until they are 100% eliminated.

Even with me removing 1/4 of the foliage as a further precautionary measure the size of the plants has doubled since I last took my photos. This whole pest issue has definitely set the development by at least 4-6 weeks, but at least now I know how to deal with them in the future. I am very much looking forward to just letting the plants do their thing with minimal pruning.

The crazy thing is that blossom production has not slowed down one bit through all this, even though I intentionally removed blossoms in relation to how much foliage I was pruning out.

Going to do a full nutrient change tomorrow. I switched to a dry nutrient powder (MASTERBLEND 4-18-38) which is a lot cheaper than the liquid one I was using… first time trying it so hopefully the plants like it. Taste and quality of the strawberries has gradually been increasing as I resolve each issue but I will have to wait another two weeks to try them as the imidacloprid clears out / breaks down.