If you've just received an import order from us, thank you and I hope you enjoy them!
This post will guide you through a tried and tested method I've been using for years to harden and acclimatise imported bareroot plants to my own growing conditions.
Visual Check
Check your plants for any signs of crown or stem rot, and mold or fungus. If signs are severe, or if any plant arrives dead (DOA), please refer to the Refund Policy page, and if needed, contact us immediately.
More often than not, there will be some dead or dying tissue on plants that have been in transit. Most often this occurs as browning/blackening foliage or some proportion of dead root mass. Remove all dead plant matter with a disinfected tool.
Specifically in Nepenthes, pitcher necrosis (blackened, dead or dying pitchers) during transit is common. This is normal and should not be a cause for concern. Remove affected pitchers by cutting the tendril where it joins the leaf tip.
Treatment
Exported plants are pre-treated with 0.2%(v/v) Abamectin (pesticide) and 0.2%(w/v) Thiram (fungicide).
You may apply a supplement or plant tonic of your choice before potting up. I personally do not, as I have not observed such products significantly improving the hardening process, especially when humidity, light and temperature are the most important considerations at this stage, which we will get to soon.
Potting
Pot up your plants with your media of choice. Match the pot size to the root mass, and consider how much moisture the roots of that particular plant requires in determining the size of the pot and the composition of your media.
I personally recommend a standard mix of 50% sphagnum moss and 50% medium-grain (6-9mm) pumice for the majority of plants that like moist, well-draining media. This mix is simple, economical and effective, providing a good balance between moisture retention and drainage. Feel free to substitute the inorganic component (pumice) at your discretion.
Importantly, the media should not be sopping wet when potting up your new plants. Aim for moistness - like a wet sponge that has been squeezed out once.
Humidity
By far the most important factor at this stage. Bareroot plants that have been in transit for a number of days can basically be thought of as in a comatose state, needing to be gently nurtured in a stable environment with minimal environmental fluctuation until they are actively growing again.
Set aside a transparent storage container with a lid. The lid does not have to be airtight but should offer a good seal. Select a size that is appropriate, as oversized containers tend to dry out more quickly and will have to be misted more regularly to maintain high humidity, compared to smaller containers in which the plants sit snug. Place your plants in this container and cover them. Importantly, do not mist your plants when they are in a high humidity environment like this, as it can easily cause leaf and stem rot, or induce proliferation of mold, fungi or bacteria. The container itself however, can be misted to bump up humidity before the plants go in.
Some of your plants may by wilting at this point, but the high, stable humidity afforded by the covered storage container will get the plants to perk up in 1-3 days. In some cases, it may take up to a week or so. Aim for stable, high humidity above 80%RH.
Light & Temperature
Place your covered storage container in light that is equivalent or slightly lower than what the plants need. For the first week or so, avoid strong, direct light or an excessive photoperiod if you are using grow lights. The container should also be placed away from areas that are hot or cold, or that fluctuate wildly throughout the course of a day. Room temperature (25C) is ideal, but not crucial.
The Method
Monitor your plants for signs of new growth once they are in the conditions described above. The process can take anywhere from 2-4 weeks, but also depends on the type of plant and environmental conditions. Lower light and temperatures lengthen the duration.
I generally leave my plants in the first condition (>80%RH, fully covered) for at least a week before checking on them. If the plants look turgid, healthy or show signs of new growth, start reducing the humidity by one of two ways:
- leave a small gap in the lid
- transfer the plants to another container that has a few small holes drilled into the walls
Once transferred to the second, lower humidity condition described above, monitor your plants for the first couple of hours and days. If plants wilt, transfer them back to the first condition, because it is likely that the roots are not actively absorbing water or growing.
If however your plants look healthy and turgid, repeat this process weekly of lowering humidity by increasing the gap in the lid or transferring to containers with larger holes. The idea here is to keep reducing humidity gradually, until it matches the humidity of your growing environment.
Take things slowly and gradually, giving the plants time to adapt to lowering humidity, instead of inducing drastic and sudden fluctuations. The longer the process, the easier it is on the plants. The humidity drop between conditions should not be more than 20%RH each time, but measuring humidity is not entirely necessary, as the plants themselves will show you if they are doing well or not. Along the way, water your plants sparingly if the media does indeed dry out.
By the end of the process, the plants have acclimatised to the light, humidity and temperature of your growing environment. Before taking them out, check that they are actively growing before placing them on your bench or rack, where they will join the rest of your collection!