To my embarrassment after spending lots of time preparing the poor 'soil' at our house in Mooloolaba QLD, the Jacaranda tree I planted many months ago is still not flourishing!
Our block is very sandy / clayey with not much organic matter. I think the hole I dug was big enough & I used plenty of Garden Mate before & after planting. I backfilled with nursery recommended garden soil improver / compost.
It's lost all it's lower branches & I'm now thinking I should cut it back to hopefully encourage new growth or else it may be doomed to fail. My thoughts are that it's a risk worth taking because it will probably never come good? If I cut it back, how much should I take off - 1/3? 1/2? 2/3?
Thank You
Hi Tommo When you transfer any plant to your garden you need to refill the hole with the soil that came out of the hole you have created. Compost and other organic matter can be added to the original soil but the original characteristic need to remain the same. If hole is deep, fill the base with original soil and then back-fill with the soil/compost mix. You do this for two reasons, firstly the you want the roots to continue to grow out of the hole and into the garden bed; if the soil in the hole is much lighter the roots may grow around the sides of holes as it is easier that pushing into heavier soil. Secondly, the water may not drain out of the hole as quickly and create a perched water table. I would prune the dead branches close to the trunk, just above the branch collar and leave the other branches. Jacaranda do not respond well to pruning, they send up ugly upright shoots and the tree can loose its shape. Jacaranda do need lots of water during the establishment phase, but the soil needs to be well drained so check the soil around the tree is moist by not wet. If the tree looks really unwell it may be worth digging up the plant, and checking the root health, the drainage of the hole and replanting as stated above. Whilst preparing the hole, place the plant in a Seasol mix, this helps reduce transplantation shock. When you put replant make sure to keep the root ball depth to the same as before, the surface top of the root ball should be at the same height as the soil level.
I have now seen your photo. The jacaranda seems to be growing very tall, this looks extremely unnatural, have you been trimming branches off. I would leave it for until next year and see what happens.