A discussion on propagating Japanese Black Pines from candles
Posted: March 12th, 2022, 1:43 pm
I recently mentioned in another thread that I’ve had success this year in propagating Japanese Black Pine seedlings from candles. At least, after a few months they still seem to be alive, and I'm positive about their future. I understand that this success may be unusual, so this thread is to share my experience and to allow others to share theirs. It's important to note that I'm in suburban Melbourne, and that this has been a La Niña year, with cooler average temperatures and higher humidity than most summers.
I acquired my first two JBPs this year. One is estimated at around 3-5 years old, the other is more established and is probably 10-15 years old. Neither was ready for decandling this year, but both had some branches that I intend to remove this autumn. I decandled the branches planned for removal and tried to propagate the candles. I hadn't expected success, so whatever records I have and all photos are very much post hoc.
Tree age: the candles from the younger tree had a higher survival rate (4/5) compared to the older tree (1/3). However, the smaller tree had longer candles, a significant confounder.
* Terryb has previously documented success in propagating candles from a 1.5-year-old tree
Fertilising before decandling: more is probably better
I don’t believe that either pine had been fertilised much this season before I got them. The larger one was from a private collection whose owner lacked the time. I started heavy fertilisation for the smaller pine from early December (about 5 weeks before candle harvest), but the larger tree only had 1-2 weeks of fertiliser.
Timing of candle removal: First week of January.
Candle size:
- All candles were cut proximally – i.e. only a short stub of residual tissue was left (2-4mm).
- The length of candles varied. The ones that were about 2-3 cm long survived; shorter ones (<1.5cm) did not. I think this related to rot when needle sheaths were below the soil surface.
Needles: Proximal needles were removed, leaving about 10-12 distal sheaths and their respective needles.
Hormone: I used purple (3g/L) Clonex gel - each candle was dipped for about 30 seconds.
Soil mix: 1 part coir peat, 1 part perlite.
Water: heaps
- All candles were kept in a water tray for a solid month, until the hot weather started to recede.
- Some were left for longer - several of these developed rotten-looking needles and died. These were also the shorter ones.
Sunlight: Candles got about 5 hours of sun each day for their first month, from 1000-1500hrs (the sunniest spot available to me).
Some of the above differs from my original post, and is based on going back carefully through pictures, as well as autopsying failed candles and unearthing a few successful ones to check candle length and root development.
Photos: - A successful candle at 6 weeks (very tiny roots, unfortunately out of focus) - Two successful candles. All successful candles were placed at about this depth, with needles just above the soil line but not touching it. - All in this pot failed; all were planted with at least a few needles emerging below the soil line. The one alive in this photo (taken at about 6 weeks post-decandling) went rotten and died shortly after, and on autopsy was only about 1cm long.
I’d be keen to hear others’ tales! What has worked for you? What hasn’t?
I acquired my first two JBPs this year. One is estimated at around 3-5 years old, the other is more established and is probably 10-15 years old. Neither was ready for decandling this year, but both had some branches that I intend to remove this autumn. I decandled the branches planned for removal and tried to propagate the candles. I hadn't expected success, so whatever records I have and all photos are very much post hoc.
Tree age: the candles from the younger tree had a higher survival rate (4/5) compared to the older tree (1/3). However, the smaller tree had longer candles, a significant confounder.
* Terryb has previously documented success in propagating candles from a 1.5-year-old tree
Fertilising before decandling: more is probably better
I don’t believe that either pine had been fertilised much this season before I got them. The larger one was from a private collection whose owner lacked the time. I started heavy fertilisation for the smaller pine from early December (about 5 weeks before candle harvest), but the larger tree only had 1-2 weeks of fertiliser.
Timing of candle removal: First week of January.
Candle size:
- All candles were cut proximally – i.e. only a short stub of residual tissue was left (2-4mm).
- The length of candles varied. The ones that were about 2-3 cm long survived; shorter ones (<1.5cm) did not. I think this related to rot when needle sheaths were below the soil surface.
Needles: Proximal needles were removed, leaving about 10-12 distal sheaths and their respective needles.
Hormone: I used purple (3g/L) Clonex gel - each candle was dipped for about 30 seconds.
Soil mix: 1 part coir peat, 1 part perlite.
Water: heaps
- All candles were kept in a water tray for a solid month, until the hot weather started to recede.
- Some were left for longer - several of these developed rotten-looking needles and died. These were also the shorter ones.
Sunlight: Candles got about 5 hours of sun each day for their first month, from 1000-1500hrs (the sunniest spot available to me).
Some of the above differs from my original post, and is based on going back carefully through pictures, as well as autopsying failed candles and unearthing a few successful ones to check candle length and root development.
Photos: - A successful candle at 6 weeks (very tiny roots, unfortunately out of focus) - Two successful candles. All successful candles were placed at about this depth, with needles just above the soil line but not touching it. - All in this pot failed; all were planted with at least a few needles emerging below the soil line. The one alive in this photo (taken at about 6 weeks post-decandling) went rotten and died shortly after, and on autopsy was only about 1cm long.
I’d be keen to hear others’ tales! What has worked for you? What hasn’t?