My December 30th 2012 next to last batch of 100 seeds, which spent 3 months in a refrigerate at 0C produced twelve (!) germinations as of today. This is full 5 weeks. On January 24th 2013, I decided to start a new batch of 100. Since I did not have any left in the fridge, I decided to try an unstratified batch.
As of today, I have 32 germinations from that last batch. This is after 2 weeks on a coffee filter in a much smaller container. I have been moving germinated seeds that reached about 5-7mm in length into the brown patch. The first two, that germinated within three days were already moved to the white patch into the real soil.
Since this batch germinates much faster than anything I experienced before, I started putting two seeds per cup to save on effort dealing with dozens of new seedlings:
I continue to water seedlings on the brown patch with a small pipet, applying water in a very close proximity to the seeds. Most of the cup remains dry. I believe this method keeps roots reasonably moist while the rest of the cup acts as a large dry buffer that keeps negative effects of over-watering suppressed.
A very low percentage, around 10% of the seeds perished on the brown patch since I started using this method. Previous methods had over 50% mortality rate. The downside of this new method is that it requires extremely careful watch. Since there is so little water involved, it's easy to miss 6-10 hours and then the seedlings react violently, like in this example:
Fortunately, all seedlings recovered and straightened out after water was added. All fatalities after the new method were due to seedlings not emerging properly above ground for one reason or another.
There is currently 22 plants on the white patch, with a couple showing distress signs. At this time it's 22 out 106 germinated seedlings. With this new influx of fresh seedlings, now there is a hope to have white patch close to its intended capacity of 30.
Here is a quick update on some notable white patch seedlings.
#39 continues to outgrow every other seedling and if anything, its growth is still accelerating. It starts to look like a small tree. The soft stem at the bottom hardened, somewhat cracked and is now adding some thickness. It keeps branching vigorously:
#39 February 7, 2013. Two and a half months.
#15, the seedling that had a "surgery" in December, continues to develop well, but is still not able to catch up with top three:
#15 February 7, 2013. Three months.
#24, the subject of January surgery, also appears to do fine. It has not shown the explosive growth of #15 immediately after the procedure, but looks on par with other seedlings of similar age that did not experience trouble:
#24 February 7, 2013. Three months.
#38, the second best seedling still looks extremely bent, but continues to add volume. There was a positive change in color of the growing top region. Last time it was reported that it started turning very light green and even bright yellow. I started controlling moisture content much tighter in this sample over last two weeks, which in practical terms meant NO WATERING. There was plenty of moisture in the core of the container, hovering around 3:
#38 February 7, 2013. Two and half months.
I am discovering that the cactus soil I have been using lately holds water a bit too tightly for young sequoias. I started adding more of better draining soils to the latest additions to the white patch.
Last but not the least, my daughter's #44 is doing very well. It is now surpassing its previous twin #42 by a safe margin:
#44 February 7, 2013. Two and a half months.
Half of the white patch February 7, 2013.
Boris, I wonder if the small scale watering with pipettes might not cause local variations too extreme for the delicate seedlings to handle. The variation in the composition of the soil, immediately proximate to the root may or may not reflect the moisture pattern you observe on the surface. It occurs to me that there may be subsurface wicking, away from the roots, even drying them out, though the surface pattern may reflect that water has been delivered. Also, since I see a distinct patter on the surface indicating dry and moist regions, it appears that the variation during the watering cycle may be so significant that the roots are actually going through drying cycles each day. Is there a way you can increase the overall moisture content to some level nearer optimal before doing you're pipette watering? I like the idea of local delivery, but fear it may be a poor substitution for overall moisture management.
ReplyDeleteAngus, a fair concern. I have not described observations below surface much in this blog. I will write more about it with pictures later. For now, here is a summary of what I observed with local watering:
ReplyDeleteLocal watering results in extremely healthy looking tap root, mostly white, sometimes almost transparent, thick and long. The length of tap roots is approximately 2 inches after 10 days.
Water distribution pattern looks like a cone with its widest part on the surface. Water seems to flow along the root path inside the container. I apply water somewhat wide, about 1.5 inch diameter around the stem. I did multiple examination of both dead and healthy samples. In healthy cases I was able to extract a cone shaped clump of soil 1 inch diameter with a plant sitting on top of it and the root completely inside.
Partial drying up seems to make them stronger rather than weaker. I did notice that if I get a seedling unhappy but catch it early, it springs back to active growth. I do not understand the mechanism and attempt not to push it too much.
I do vary amount of water for each sample based on how big the part above ground is. While I apply about 1-2ml to the seeds that have not emerged or just emerged above surface, I add 2-4ml to the seedlings that unfurled the green needles. 10 day seedlings get around 8ml per watering. The youngest seeds/seedlings get watered twice a day, while the older one get water once a day or sometimes every other day.