25. Self-Watering Propagation Tray
Will a self-watering seed tray work for propagation?
I tried something new this year for propagation: self-watering trays. So far, the results are mixed.
Last year, I had tried, and mostly failed, at propagating cuttings. I suspect that one of my problems was waterings. Either I would forget to water them and the soil would dry out since I left the cuttings exposed to the elements they would get soaked with rain.
I had another problem: soil. When I first used the trays in April, I used soil directly from my garden. By July, most cuttings had wilted. By October, only a few hardy cuttings remained. We’re now mostly starting over (see photo above from October) with sand. Join me for another propagation experiment!
The Tray
I purchased the “Organic GrowEase Seed Starting Success Kit” from Gardner’s Supply Company.
The self-watering tray works on the principal that a reservoir of water at the bottom of the tray soaks into a capillary mat that sits right below the plant trays. Water then slowly seeps into the soil. The water reservoir only needs to get filled every few weeks.
The kit comes with the tray and a bag of seed starting soil — see my cautionary tale below!
Gardener’s Supply Company Self-Watering Tray
The Medium
It was only this year that I realized using organic soil might be causing the root rot that destroys my cuttings. I read that using a medium without much organic matter that drains well may give you better results. When I first started using the self-watering tray this summer, I had not realized this yet. So my first cuttings used a mix of soil from my garden along with the seed starting soil that came with the trays. This may have been great for seeds, but not the case for cuttings. Most of my cuttings from earlier this summer did not root; with the exception of my Redclaws Escallonia cuttings which are growing like weeds!
What medium should I use? I am testing out sand. I pulled out all of the dead/dying cuttings and replaced the holes with sand.
I also have one tray with the medium that I am testing out in my covered propagation bins:
1/2 Sphagnum Moss
1/2 Perlite
Parent Plants
Here are the parent plants that I am trying to propogate in these bins.
Tray #1 Timestamp
Here is a snap shot of each tray from October 15, 2023 with my best guess as to what is growing in each tray.
Tray #1 Original soil medium:
Left slots = Red Claws Escallonia
Middle slots (2) = Vine Maple (all others died)
Right slots = Cherry Laurel
Tray #1 Sand filled trays:
All are Azaleas
Tray #2 Timestamp
Tray #2 Original soil medium:
Top row right (1) = mystery Barberry (all others died)
Middle slots = Red Claws Escallonia
Tray #2 Sand filled trays:
Left row = Japanese Barberry
All others = Mystery Pool Plant
Tray #3 Timestamp
Tray #3 Original soil medium:
Top row (2) and Bottom Right = mystery Pool Plant
Bottom row (1) = Vine Maple (looking kinda sad/brown)
Middle (a few, hard to tell) = Cherry Laurel
Tray #3 Sand filled trays:
Right rows (6) = Madrona Tree (this will likely fail, but I was just curious if I could get it to root!)
Left rows = Burning Bush Euonymus
Tray #4 Timestamp
Tray #4 Moss & Perlite filled trays:
Right side = Steeds Holly
Left side = Cherry Laurel
Storage
These trays are now living inside the greenhouse.
The next step is to remember to fill the reservoir from time to time and hope that at least some of these will root!