Small Fish, Big Pond

Surprisingly long, although I wouldn’t recommend it.

Had a little problem last week. Temperatures in Utah have been reaching triple digits with sunny clear blue skies all day long. I had gotten used to the water requirements of the hydroponic garden being about a loss of 4 gallons every two days or so. However with the days getting hotter and the plants getting larger (more surface area and breathable surfaces), the water requirements have been getting bigger.

The problem was that I let the plants go 3 days without topping off the water supply.

I knew that with the smaller nutrient reservoir watering would be more frequent and even thought I might setup a second reservoir with a siphon of something to double the usable volume. Unfortunately this all came to a head when I checked my plants and they had been basically dry for most of the day.

Everything was extremely wilted looking and a few leaves on the cucumbers had dried up (they feel rough and dry even when healthy so it’s hard to tell). I immediately refilled the water and turned the pump on to wet the plants again. By evening everything was looking better but it was obvious the cucumbers hadn’t weathered the dry spell as well as the peppers.

The cucumbers on the far ends lost the tips of some of the leaves but bounced back really well besides that.

The peppers looked just fine afterward. I can only figure this is because their roots are thicker than the cucumbers which have fine roots. Enough moisture is retained in the plant that the cells didn’t die and when water was brought back they revived like putting a dry sponge in water.

But the cucumbers nearest the drain didn’t do so well. While enough survived that I could probably have kept them alive they weren’t likely to produce much fruit and what they did would likely be at the end of the season. Better to just chuck them and star anew with a late season plant.

So when the weekend came round I got the tallest pre-planted cucumber at the farmers market and swapped it into place.
The first evening was a bit rough, the above picture was taken about 30 minutes after transplant in the middle of the 100F afternoon. In just 30 minutes the plant went from looking normal to looking faint. Obviously the shock of going from soil to liquid + heat + a root system not adapted to the hydro system was a bit of a shock. But although the leaves looked and felt flimsy they were still soft with moisture and not dry like the plants that had been left without water; by the next day they looked vibrant and were already perking up.

Here’s the wilty peppers from the same time. Obviously it’s hard on plants dealing with 100 degree heat just like it is with humans. It’s no wonder they’re going through about 4 gallons a day right now. Luckily I don’t need to re-do the nutrient each day. The plants take what they need from the nutrient and leave the rest, so as the water level goes down it’s mostly H2O being used and the nutrient solution becomes more condensed. Adding water brings the nutrient back to the normal PPM. Although for that reason it’s good not to let the water get too low and the nutrient solution too condensed.

Here’s the cucumber that needed to be removed. A shame to lose it, it was the largest and had already produced 3 cucumbers this year. As you can see one plant was still very green and could have pulled through, however since they’re both in the pot together there is no easy way to separated them and just replace one.

Also notice how dense the root mat had gotten, it actually continued to the right just as far but because of the peppers next door I couldn’t separate the roots and had to cut them off to get the plant out. The ½ to 1 inch thick mat at the bottom of the planter retains a lot of moisture due to wicking action once the pumps go off (or water runs out) which probably helped them survive going a day without water. It would also explain why the plant closest the drain fared the worst, since it drained off quicker than the cucumbers at the other end of the planter.

Here the root cup after the plants had been cut and tossed to the compost. You can see how much the roots come out of the cup in every direction, the cup is held above the bottom root mat so most of these roots are held above the nutrient with the sprayers spraying the sides. But the plant still branches out in every direction to soak up every drop it can.