Tag Archives: Summer

Emergency Repot

I recently watched a Bonsai Mirai video about post collection care with world renowned collector Randy Knight. He spoke frequently about his sawdust bed that he uses to heel in “danger trees.” I got the opportunity to try that myself as I came home to what I’m pretty sure was a great lizard chase by my dogs…

Randy discusses that he uses coarse sawdust, not small particles. I happened to have a friend that uses a lathe and has been giving me black trash bags full of sawdust for awhile now.
A couple of tips when using sawdust:

  • Make sure to wet it REALLY well. The first time you soak sawdust it absorbs a ton of water and has a hard time getting everywhere, so make sure to be liberal with the water you’re using.
  • Pack the sawdust in good and chopstick or poke around to get the sawdust into whatever root system is there.
  • Layer several inches of sawdust on top of what would be the rootball. This helps to keep any major fluctuations in water or temperature from the rootball.

Here are photos of me digging down and checking the moisture after watering for awhile.


Packing in the sawdust for a final time.
After packing and before adding another bag on top.
After adding and wetting the top layer of sawdust.


After securing the tree in, I went to further inspect the damage.
I pulled out portions of the leftover root system to see how the roots were doing before the wild lizard chase. I was mostly pleased with what I saw.
Plenty of capillary roots growing. Randy also mentioned that new roots almost never grow in the leftover field soil, but in the pumice immediately around the field soil.
While I had to experience this sad destruction of my collected California Juniper, I’m glad I was able to see that I was having success with what I was doing. Hopefully I don’t have another casualty on my hands.


I’ve wanted to document what I’ve done as far as propagation for a long time. I haven’t seen anything that is very in depth about propagation with specifics. Here is the first of many about different plants and scenarios that should help to narrow down any misconceptions about plant propagation that might be out there.

Before I talk about the successes and failures I want to describe the propagation medium, situation, and frequency of watering.

*AHS Recommendations refers to this book by The American Horticultural Society on plant propagation.

Propagation Box

Propagation Intermittent Misting System

Plant Propagation Box

Dimensions: 2′ x 10′ x 8″

Medium: 100% Silica Sand – Lowe’s 100lb bag

Watering System: Misting system x 2 – Orbit’s Misting System

Watering Frequency: Misting for 3 minutes every hour – Raindrip Timer

Location: 100% Indirect sunlight next to the garage (Helps retain heat)

Weather: Average Monthly Weather (Also windy daily which would enter through the small openings since the box was not airtight)

Zone: USDA 8 / 9 and Sunset Zone 9 – 11 (technically 10) | We seem to be a bit above and below of the zone due to weird extremes within our zone.

Cutting Preparation: Very rarely did I use rooting hormone, large hardwood cuttings were cleaned around the edges on the bottom with box knife, no intentional “scoring” of the bottom of woody cuttings, and no anti-phytophthora dipping substances.

Lizard/Animal Tank Box

Dimensions: Unimportant, but I saran wrapped the window screen top to keep it more airtight.

Medium: Pumice and Silica Sand mix. About 80% sand to 20% pumice.

Watering System: Spray bottle

Watering Frequency: Anywhere from 2 times a day to 1 time every 2 days.

Location: 90% Indirect sunlight with the 10% being morning sun.

Weather: Average Monthly Weather (Wind not nearly a factor as it is almost airtight)

Zone: USDA 8 / 9 and Sunset Zone 9 – 11 (technically 10) | We seem to be a bit above and below of the zone due to weird extremes within our zone.

Cutting Preparation: Very rarely did I use rooting hormone, large hardwood cuttings were cleaned around the edges on the bottom with box knife, no intentional “scoring” of the bottom of woody cuttings, and no anti-phytophthora dipping substances.

Successful Species

Crepe Myrtle – Lagerstromia sp.

AHS Recommendations – SW cuttings in Summer, Difficulty: 2

These would root from softwood cuttings, semi-hardwood cuttings, and hardwood cuttings. All were taken between late Spring and late Summer. One set of hardwood cuttings were taken mid Summer and left on the ground for a day, then I came collected, cleaned the edge of the bottom of the large cuttings with a box knife to clean the cambium layer for easier rooting. With softwood and semi-hardwood cuttings I’d say I had about 70% success rate. Some of their leaves wilted and rotted. Large hardwood cuttings has been near 100% so far.

Waxleaf Privet – Ligustrum Japonicum

AHS Recommendations – SW/SH from early to midsummer, Difficulty: 1. HW from late autumn to midwinter, Difficulty: 1

These root fairly easily without too much work. You can take SW, SH, and HW cuttings. Hardwood cuttings took extremely well under the constant wet conditions. With SW cuttings I had a lower success rate around like 60% – 80%.

Boxwood – Buxus sp.

AHS Recommendations – SW/SH early summer to late autumn, Difficulty: 1

The SW cuttings will root with an almost 100% success rate. I haven’t taken any hardwood cuttings, but heard that they root just as well.

Green Japanese Maple – Acer Palmatum

AHS Recommendations – SW early summer, Difficulty: 2

These had a low success rate. I would say about 40% with the SW cuttings that I took. They also didn’t transplant well due to being in an almost out of zone area here. I had a few larger hardwood cuttings that I took in Summer that rooted, but I wasn’t able to keep them once I got them out (personal flaws and care taking problems).

Barberry – Berberis (Specifically Crimson Pygmy)

AHS Recommendations – SH midsummer and HW in winter, Difficulty: 2

I took only a few SW cuttings of this and they all rooted wonderfully. 100% success rate and it lived in the box for a few months.

Star Jasmine – Trachelospermum jasminoides

AHS Recommendations – SW/SH cuttings in Summer/Autumn, Difficulty: 1

I took a few cuttings and the only ones that didn’t survive were due to the mist nozzle plugging that resulted in no water being delivered to that area.

Burning Bush – Euonymus Japonicus

AHS Recommendations – SW/SH/HW cuttings from Spring to Fall, Difficulty: 1

These did great and rooted super easy with a high success rate. They also transplanted well and survived a few knockdowns from the dog, and emergency repots midsummer from the same thing.

Fruitless Mulberry – Morus sp.

AHS Recommendations – HW cuttings late Autumn, Difficulty: 2

I had around a 70% success rate with rooting SW cuttings of Fruitless Mulberry. I also took cuttings from the root graft of a fruitless mulberry and they rooted fine as well as a SW cutting. I also was able to take HW cuttings while leaving on the leaves. It rooted, produced new growth, and was transplanted into soil with indirect light outside of the propagation box. This all happened midsummer.

Pomegranate – Punica Granatum

AHS Recommendations – Not found

The pomegranate cuttings didn’t do well under such wet conditions, but they did great and thrived in the aquarium tank box. They rooted really quickly and grew faster than any others to date.

Chinese Elm – Ulmus Parviflora

AHS Recommendations – SW/SH cuttings midsummer, Difficulty: 2

These were really hit and miss, and the AHS section mentions that they need to make good growth to survive the winter. Suggests to keep them frost free and to pot them up before Spring commences. These did well in both the tank and the propagation box.

Rosemary – Rosmarinus

AHS Recommendations – SH/HW cuttings and seeds in spring, Difficulty: 1

I took softwood cuttings which isn’t recommended at all, but they did awesome and thrived in the propagation box. They haven’t transplanted very well once I moved them outside without major protection.

Gingko – Gingko Biloba

AHS Recommendations – SW cuttings, Difficulty: 3

These SW cuttings rooted 100% of the time. They need good protection when transplanting. Several of mine dried out from the wind even with nearly 90% indirect sun.

These are the species that worked for me. In the next post I’ll talk more about the failures and what I learned from them.

Crape Myrtle Hardwood Cuttings

I had a few pretty serendipitous opportunities to get some thick Crepe Myrtle cuttings. I barely caught someone on my local Facebook pages that had trimmed several large multi-stemmed Crepe Myrtles and I was able to stop by and rummage through the pile before it got hauled off.

You can see below that after only a week or two several of the hardwood cuttings have sprouted leaves.

This is what I use to root my cuttings. This is a 2 ft. x 10 ft. x 1 ft. box filled with silica sand from Home Depot. I used two misting systems from Lowe’s meant for the patio. I also put a timer that goes off every hour for 3 minutes. Then topped it off with a thick clear plastic sheet. This is in full shade all day long.

Here are the cuttings a few days later. You can see that the leaves have sprouted and have grown several pairs of leaves. Only one has roots so far and I’ve moved it and put it in a terra cotta pot mixed with bonsai soil and sand and put it back in the box.

This is a fantastic way to create material to be able to work with as Crepe Myrtles grow really fast and can be multiplied with ease.

Fundamentals of Bonsai – Summer

Your tree has physiological responses to the heat of Summer. It goes into a semi-dormancy to cope with high temperatures, scorching sun, and preparation for Fall.

Crape Myrtle Flowers

Protecting your tree during Summer is of utmost importance. Almost every tree should be shaded from afternoon sun, especially in the Summer.


If you miss watering even for a day you may lose trees. This is not the time to be skipping watering, however it happens to be the time for vacation. If someone is coming to water my plants I tell them which plants to water and watch them do it without any instruction first, then I write down everything they have to water and give more specific instructions like “Water it twice as much as you think you should.” It also wouldn’t hurt to have an automatic sprinkler to give it another watering depending when they plan on watering.

Summer Dormancy

Once the temperature reaches the mid 90s your tree will go into a dormancy and cease to photosynthesize in order to prevent significant water loss. Your tree uses water as a cooling agent while transpiration and photosynthesis cease. Watering your tree with scorching hot water will not aid the tree in cooling itself. Make sure to run water out so you water with cool water.

Crape Myrtle Bonsai Tree Flowering

Summer Damage

Certain species of trees can be damaged by leaf burn from the Summer sun. This happens commonly with Japanese Maples among many others. Assuring your tree is shaded from the afternoon sun will greatly aid in reducing leaf burn and overheating problems. It is also common to experience leaf burn on leaves that have no hardened off yet and don’t have a cuticle to protect the leaf from the sun.

Root damage is also common if the pot is not protected from the sun. Black plastic pots, clear glass pots, or even your average bonsai pot can overheat and scorch the roots. Other than a shade cover you can do other things to prevent this by shading pots with foliage from other trees, grouping them together, laying some type of screen over the pot that still allows air to pass through (Window screen, etc.).

Summer Repotting

It is said that some tropical and mediterranean trees like to be repotted in the Summer, but personally I wait until the temperatures reach 50+ degrees regularly and then I repot. This happens to land somewhere between Spring and Summer. I have repotted Ficus, Olive, Schefflera, and Portulacaria Afra in later Summer without any problems, but prefer to do so earlier in Summer to allow a longer window for recovery throughout Summer.