Repotting Burseras

It is warmish, springlike, and with steady watering to make up for the lack of winter rain, Burseras and other succulent trees are beginning to leaf out, a perfect time to repot.  The energy is in the plants to cover from any root work, and it is early enough in the year that the roots will settle and start to grow before any top work needs to be done.

Several field collected plants have been growing in mostly pumice in gallon pots for the last several years, recovering, growing some root structure.  Two were ready to join previously potted and worked plants.

The first Bursera, growing in the last couple of years in a gallon pot, and getting the barest of top work to encourage some back budding.  It has a near spherical caudex, and some of the longer branches will be trimmed to back bud during the next few years.

Out of the pot, the mostly pumice mix can be seen.  There is a little coir and some weed roots towards wht bottom.

This pot was made for this Bursera, the light clay, iron oxide with the darker brown will offset the plant nicely, while the rough texture is more reminiscent of the rocky environment these come from.  The deep pot was made to accommodate the long tap root.

 Then the surprise.  When planted the tap root was long, nearly to the bottom of the gallon pot.  After several years in the pot, the bottom of the tap root rotted off, and all the roots came from much higher up.  The bottom of the tap root was hard, so the rot had started and finished.  Time to reconsider the potting choices.

Pot choices.  The original is on the left.  Two alternatives, one with similar pot angles, emphasizing the vertical motion, the middle wider and more likely to emphasize the sprawling low stems.  The pot on the right proved to be too narrow to comfortably hold the root ball.  The middle is just a bit bigger than needed.

My current potting mix consists of pumice and black volcanic rock.  The volcanic rock is larger than the pumice and gives added room for air to reach the roots.  The pumice has a fair amount of powder which can set up like concrete around roots and prevent air from reaching hair like roots that pull in much of the water. The mixed ingredients are put into a flat with screen in the bottom and washed together.  There are no organics in this mix.  This is similar to the mix that some Bonsai growers are now using.  There is nothing to decompose.

Top view showing the potting mix and Bursera.

The near final potting.  Top dressing will get added when I get ready to show this.  In about three weeks, leafing will be complete, and some of the long top growth will be cut back.  Some of the growth that is beginning to get too high will be wired back down.  I've resigned myself to arguing with show clerks about keeping the point of the pot in the front.