Bonsai: Summer Maintenance

With no national shows in Spring and very little club activity due to Covid-related restrictions this year, it gave the opportunity to allow trees to just grow, recover and gain some vigour. Or is it just laziness or procrastination that allowed for some of my trees to get out of hand, especially in the weed growing department. With a bit more time on my hands due to the summer break, it is time to get some control back.

Before on left and after basic maintenance work on the right. This is a Privet (Ligustrum).

My normal way of working is to start at the bottom and this case was no different. I ignored the weeds for now and first took all the dead little twigs out. In the process of doing this, I discovered a solo paper wasp nest and had to remove the culprit and the start of the nest first.

Wasp nest.

Next job was to take all unwanted growth out. This included spent flowers, crossing branches, branches going against the flow, branches and twigs growing up or down. This created a more natural pad shape and with the trunk now more open, it was decided to turn the tree very slightly to the right. That means repotting and in the middle of summer, not such a great idea. This tree species is treated as a weed in New Zealand due to its indestructible nature, spread all over the place and pushing native species out. In other words, it is quite hardy.

The tree was taken out of the pot, some old soil was raked out, but no roots were cut. This took care of the weed problem as well. Back in the pot with some fresh soil and also the slight twist. It is now well-watered and in the shade for a few days before it goes back on the bench.

Weeds: As Bonsai grow in relatively small pots and the soil medium is quite porous, you do not want weeds in your soil competing for the same food source. It is better to keep an eye on this and remove weeds as soon as they appear. Not only will you have more nutrients available for the tree, but by removing weeds while small, you also do not disturb the tree roots when you have to remove larger weeds.

In summary for summer maintenance:

  • Remove all dead and sick leaves, twigs and branches.
  • Seal all big cuts.
  • Remove pests.
  • Clip to shape and where necessary apply light wiring.
  • Remove all weeds from the soil and pot.
  • Only work on the root ball if it is not invasive work and you have the ability to provide exemplary aftercare. Do not cut roots at this time of year.
  • Water and keep in a sheltered position.
  • Apply liquid fertiliser or tonic and then follow up with a slow release granular fertiliser. I use Seasol and then a well-balanced fertiliser as Summer progresses into Autumn. I also use Rhizotonic when available.
  • Fro Northern hemisphere readers, please take note that these trees live in the Southern Hemisphere (New Zealand).