Watering: To Wick or Not To Wick

When we started ramping up our return to gesneriad growing in early 2023, one of the major concerns was keeping the plant collection watered while we were away. Since travel plans also are ramping up in retirement, this was a source of consternation. I started investigating wick watering, a technique used by many growers with much success. Helpful correspondence with other enthusiasts, as well as reviewing back issues of the Gesneriad Journal provide much information. I decided to give it a go. I went "all in" and nearly all the plants I acquired were put on wicks from the start.

Early Wicking Setup

For the wicking material, I used acrylic yarn as recommended. The yarn was thoroughly wetted before using and extended up through most of the pot. I purchased a large number of predrilled reservoir containers. Over the next 18 months I experimented with the length of wicking inserted in the pot, and even the number of wicks used based on pot size. I made minor adjustments to my potting mix but essentially kept the same 1:1:1 mix I always use.

I did find wick watering to be somewhat counterintuitive, since some gesneriads prefer to dry a bit between watering, while others require constant moisture. Nonetheless, the plants seemed to do well enough. But I was not wholly satisfied.

It was not unusual to return from a trip and find some pots that had just stopped wicking up water. Even plants that had been doing well for weeks or months would abruptly stop drinking. This was a source of frustration. When I wasn't traveling, the failures would be easy to see before any real damage was done as I'd notice the water level in a container not going down.

There were other issues that plagued me as well. Repotting requires replacing or working around the wick. Wicking also brings with it an algae issue. Some growers just ignore the green growth, others add a small amount of Physan 20 to the water and fertilizer solution to help control it. I had success with the chemical route.

I also found the technique problematic when rotating fertilizers, something I like to do regularly. Switching to a new feeding formula, meant emptying out a lot of reservoirs before refilling them with a new nutrient mix.

After returning from a long weekend trip in late summer, I again found a number of plants had dried out, despite having full reservoirs. This was the final straw for me. I had given the wicking trial a good run for at least 18 months. No one could accuse me of not giving it a chance. It was just not the solution I had hoped.

"Un-Wicked"

I spent the following week revamping all my light stands. Shelf by shelf the reservoirs were emptied and wicks removed from the pots. At the same time, I partially filled my trays with gravel to provide drainage when top watering and to provide extra humidity. On the larger stands I set the pots on 4 x 8 lighting grid placed over the trays. On other stands, the plants were set on the gravel directly — for the time being.

I could now fully water individual plants on a per-need basis. It only took a few weeks before I could see a change in the plants. They seemed to have healthier appearing foliage, and I perceived an increase in blooming across the collection. The increased humidity surely helped on both accounts. I also felt the nutrients and moisture were fully and evenly getting to all the roots as the pots were getting a thorough watering each time.

For me, it was also more enjoyable to handle each pot to water, rather than simply filling reservoirs. I like the "hands on" approach.

One issue remained. I was now watering some plants, though not all, every three or four days. My goal for wicking had been to allow the plants to exist on their own for a week before needing a "plant sitter." In many cases adjustment in pot size — fewer under-potted or excessively root bound plants — was the answer with the hand watering technique.

Not content with a single big change, I recently also replaced the one remaining 20 year old fluorescent tube stand with one using LED bulbs. I already had some plants growing under LED's, so did not expect it to be too much of an adjustment or learning curve. With that change, I also purchased a plastic enclosure that fit the new stand. With the cover mostly closed, the plants go longer between watering. I am still experimenting with how much to open the cover to avoid a near-rainfall environment inside the enclosure, but I am confident that most, if not all the plants, can survive the desired week alone. I do not leave the plant stand fully enclosed when I am attending to the plants daily.

I am in the process of replacing another smaller light shelf arrangement with the 4 foot light setup as shown above. Having a consistent growing setup will make for easier plant care overall.

Many gesneriad growers have much success with wick watering. Their awards won in plant shows prove the method's viability. It just wasn't for me in my conditions and habits.