Calea Zacatechichi From Seed

[inwould]

Hi everyone,

I know a lot of people have had trouble germinating Calea Zacatechichi so I thought I'd take this opportunity to describe how Calea Zacatechichi has been successfully germinated in sub-tropical New Zealand. Sadly the whole process wasn't documented with photos from the beginning.

Seeds were ordered from SAB.

One packet (containing about 50 seeds) was emptied into a container of water and left to soak overnight. The container was kept in bedroom at room temperature (approx. 23°c).

A plastic container was filled with dirt from the forest floor.

The next morning the soaked seeds were scattered on the surface of the soil. The container was covered with plastic from a snaplock bag, making a makeshift humidity tent. The container stayed in bedroom at room temperature between approx. 23° - 25° celsius. The container was placed under a desk lamp with a 3K (warm white), 1250 lumen CFL bulb.

Every day the desk lamp was turned on in the evening for 4-6 hours. The rest of the time the container stayed in the relative shade under the bed.

Every day the plastic bag was removed for a few minutes to allow some movement of the air. If the soil did not appear too soggy, it was then gently sprayed with water from a garden spray bottle. The tent was then replaced. This airing and spraying was performed before the seeds were exposed to the light, in the hopes that the water would not sit in the soil but would somewhat evaporate and increase the humidity in the tent.

After about two weeks, and further reading, it was decided that a "cool white" bulb should be used instead. The bulb was swapped out for a 6500k, 1200 lumen "Cool Daylight" CFL.

The swapping of the bulbs was not intended from the beginning. I cannot comment on whether this swapping had any effect on germination, but I do know that it resulted in success in this particular case.

After a further two weeks or so (approx one month since sowing) the first seedling emerged. The seeds of Calea Zacatechichi have a white tip on them, which over the past month had been carefully watched. It was thought that this white tip may be the seed germinating. This was not the case. The seeds split and the roots come out the side. Lets just say it would be a mistake to stress yourself out studying the seeds day in and day out, wondering whether this white tip has "become more pronounced"..

EDIT: I found a picture I forgot I had of the germination.

Once the seedling had fully emerged from the seed, it was very carefully transferred to another identical container full of forest soil. Not wanting to disturb the shallow roots, the surrounding soil was scooped up with a pair of teaspoons. This new container was also under a makeshift humidity tent and subject to the same airing and spraying routine. This second container was exposed to at least 12 hours of light a day from the same desk lamp. The container sat under it alone all day, and shared the one lame with the first (germination) container in the evening.

Over the course of a week or two several more seedlings germinated. All in all there were now 6 little Calea seedlings in the second container. This was 6 seedlings from 50 seeds.

At this point a change in circumstances brought the seeds (along with their owner) from a home in a cool mountain region to a sub-tropical region. More seeds would likely have germinated given the chance, however the regime with the desk lamp was no longer practical so the seed container was left in complete darkness and watering was halted. The soil remained moist and no visible signs of mould were present after several months in these conditions, however no further seeds germinated.

As it was now mid October the seedlings were placed on a sheltered porch outside. Very similar to this picture, now showing a more mature seedling.

The airing and watering was continued. After a week or two of exposure to these new conditions the humidity tent was gradually removed over a course of a further two weeks or so. Initially only for a few minutes at a time but more and more as the seedlings seemed much hardier than initially thought. At this point the seedlings still did not have any true leaves, which are a very different shape to their cotyledons.

Sad to say, one day the container was accidentally hit by the full November sun peeking under the eve of the porch. The container can have been in the sun for no more than a few hours. 4 of the 6 seedlings were hit and immediately dried up and died. Thankfully the rear two were still shaded and escaped unscathed. These two were neither the strongest looking seedlings, nor the first to germinate. They just happened to be out of the sun.

As these two seedlings continued to grow and their true leaves began to appear it became apparent that there were slight differences between the shapes of the leaves and the speed at which the plant grew. The slow growing plant appeared to have more oval leaves where as the rapidly growing plant had leaves that were slightly more triangular and elongated. Not extremely so like that of the non-bitter calea, but it was definitely noticeable. As the two plants continued to grow these differences in leaf shaped lessened slightly.

When the plants were about 5cm tall they were transplanted into their own plastic containers. The containers were probably about 10cm by 10cm and about 15cm deep. The containers were filled with normal garden-centre potting mix. At about this time the plants were no longer sprayed but watered daily at the base.

By the time the plants were about 10cm tall they were at times placed in direct sunlight, to see how the would respond. I remember reading that by the time calea seedlings reach about 4 inches (10cm) tall "you're in the clear". The sun didn't seem to bother them, however they were returned to their home on the porch. At this stage the wind was of concern as the rough spring winds seemed to batter the plants around a bit, and the porch offered some shelter. In the worst of winds they would be moved to a more sheltered location temporarily.

The plants both took on quite a lean away from the light. Whether this is due to the light or the wind is unknown, as rotating the plants does very little to correct this lean.

The larger of the two plants (with the more elongated leaves) was repotted into a larger pot where it will now stay indefinitely. It is now approximately 15cm tall. It may be repotted next spring.

The smaller of the two plants (with the more oval leaves) is still in its sheltered location on the porch and will be repotted when it is slightly larger.

Edited January 23, 2016 by inwould

[solomon]

Nice write up, hope to see more.

Will be trying this out as soon as I find some seeds

and always nice to see new kiwi members

[inwould]

The second little plant is now strong enough to move to its new home in a larger pot.

[inwould]

It's been three weeks since the first plant was potted out. It's outgrowing even the weeds in the potato patch!

As the plants have aged the difference between the leaves has become more evident.

It makes one wish that more seedlings were grown so that the extent of the possible variation were more obvious. Whether there is a difference in taste / potency would be very interesting to learn.