Regular updates about the growth of the seeds we collected from epiphyllum fruit in our previous blog post. New updates will be added to the bottom of this post so you can read in chronological order from the top down.
Seeds are Sprouting 3/12/2022
After about a week in damp soil, the epiphyllum seeds we harvested in the previous post are beginning to sprout! We have six poking through the soil so far, with more popping up each day. On two of these sprouts, you can see the empty seed casing ready to be discarded. The growth of the plant will push this off soon. Since the sprouts are beginning to show above the soil, I have moved the seed tray under medium strength grow lights to prevent the seedlings from stretching and reaching for light. At thi stage they are delicate so it's a balance between providing good light, but not enough to burn or dry them out. I continue to keep the soil slightly damp at this point. As more of the 234 seeds we planted sprout, I will have to separate them from this sprouting tray to individual pots.
The goal of this is ultimately to produce our own registered hybrids, so each pot will be carefully labelled so that we can trace back the parentage accurately for the ESA registration in several years when we have not only our first flowering, but our second seasonal flowering to ensure that we the flower pictures and characteristics that we submit are stable and representative of what we expect from future clones.
Epiphyllums Do Have Leaves, But Not for Long! 3/16/2022
As true member of the Cactus family, epiphyllums don't have leaves. The flat green parts are stems or branches. More technically they are cladodes or stems adapted for a specific purpose, in this case, photosynthesis. However, they do have actual leaves when they first emerge from the seed. These initial leaves are called cotyledons (from the Latin for Seed Leaf).
Since epiphyllums have two seed leaves instead of just one, we know they are dicots (rather than monocots like grasses, for example). Cotyledons are generally temporary leaves to give the baby seedling a head start in getting established. So, while it is true that Cacti, including epiphyllums, don't have leaves, the except is during their first few weeks after emerging from the seed while they still have cotyledons. The main stem of the plant will grow up from between the cotyledons. Many plants will reabsorb the nutrients from the cotyledons into the main plant causing them to shrivel and drop off. I'm not sure how epiphyllums cotyledons progress, but we'll find out together, right here.
3/23/2022 GerminationStatus and Next Steps
We have the seeds in a plastic container with a closing lid, not airtight. There's about a half inch of soil, which I keep moist to facilitate germination. The seeds were planted on 3/3/2022, twenty days ago. The seeds were very lightly covered with soil -less than 1/16" deep. As of this morning, 35 have sprouted enough to be visible without disturbing the soil. There are more popping up each day. Yesterday we had about 25 showing, today another 10. So far that's a germination rate of 14%, but increasing daily. This is my first effort planting epiphyllum seeds so I don't have a baseline for germination rate expectations.
With the next fruit from the same parent plant (ready to be picked soon) we'll split the seeds into two groups. With one set we'll use a heat mat under the container to see if that improves the germination rate. I suspect that being of tropical origins, epiphyllum seeds will prefer the warmth. Even many non-tropical plants germinate better and grow faster with a heat mat below the planting tray. With the first batch, I took a basic approach because I just wanted to make sure I got a number of plants successfully started. Transplanting to separate them will again put them at risk since we'll be disturbing the roots and handling the tiny seedlings. We'll go over our process for that when we get there. For now, they are still too small. While I would love to see germination and transplanting success rates of 90% or more (211 new plants), I will be happy to get 30 new epiphyllum seedlings that survive to a more stable and durable size from this first fruit and then improve upon that with the next one.
It's also worth noting that even before I have harvested the last fruit from the winter flowering, the same epiphyllum is already beginning to grow new flower stalks for another round of flowers (and hopefully fruit). I carefully hand pollinated two flowers from the last batch to produce fruit since the plant is indoors and there are no natural pollinators inside my house. While none of my other epiphyllum plants are in bloom for cross pollination, I may also explore preserving pollen from the next batch of flowers for use in cross-pollinating or harvesting some pollen from the epiphyllums of other local collectors. We'll talk more about pollinating for hybridization and preserving pollen in future posts.
Germination Count 3/31/2022
As of this afternoon, we have 63 epiphyllum sprouts from our 235 seeds. Literally, more pop up every day. We are about 26 days from the initial planting. I need to optimize conditions in my next batch. I think I'll split the seeds from the next fruit I harvest into test batches. I'll use lights, heat mats, and several sprouting methods to see if I can identify which set-up will lead to the best germination rate.
As for this batch, the earliest sprouts are now showing some tiny growth of a stem coming up from in between the cotyledons. Nothing much just a millimeter or so in new growth. Hopefully, they are sending most of their energy into root development. I'll start separating and transplanting this weekend and we'll take a look at the root growth.
All of the tiny seedlings which have sprouted so far have been transplanted into individual cells and placed under a clear plastic humidity cover. We have 56 cells of seedlings with a few that have two seedlings together because they sprouted right next to each other and I didn't want to risk root damage at this stage by attempting to separate them. You'll notice in some of the photos that the growth above the cotyledons appears to have a profusion of spines. Cactus spines are the evolutionary result of what used to be leaves back in the pre-history of these plants. I mention this because the parent plant (self-pollinated) does not have obvious spines. At each areole it has either the nub of a bud, or nothing. I'll check the parent more closely with magnification another time.
Also worth noting is that the cotyledons are joined across their entire width rather than growing as two separate leaves (see second picture below).
Here are a few pictures of the current state of the seedlings taken during and after the transplanting process: