The grass tree is a very symbolic plant to have in a native garden. They can be a specimen plant, a feature plant or work well with a minimalist Japanese theme, and they look amazing in containers. Planting one can be a little daunting as there are many stories out there of them turning up their toes after a rough transfer.
Please note these instructions are a guide only and are based on planting on the NSW east coast.
The first thing you need to do is position them, often they are a central focus so make sure they are visible and not lost amongst the other plants. Place them carefully as they don’t like being moved very much, really you only have one chance to get the placement right.
Next you need to dig a large hole twice the pot size, measuring it out or marking it on the ground can be a good idea, especially in a clay soil.
Dig the hole and put the soil you have dug out in a bucket or container so that it is easy to mix back into the planting hole when needed.
Grass trees like good drainage so if you have a heavy soil it is very important to add something free draining. I like to use a good quality native potting mix, 2 bags per grass tree is usually about right. Fill the hole with plenty of the native potting mix and add some of the exiting soil too.
Cut the pot away from the root ball, the reason for this is to avoid root disturbance, you will probably find that the root ball is quite compacted and stays together. Carefully break the pot away and lift the grass tree into the hole by holding underneath the root ball.
Position the plant in the planting hole, make sure it is facing the right direction, the rotation can be visually important, especially if you have a grass tree with two heads or an interesting trunk.
Next it is very important to check the soil level, you don’t want to bury it too deeply or have the root ball exposed. You can plant them into a mound but that is created by mounding the soil of the whole garden bed, and is usually only done when the soil is a heavy clay.
The mulch should be at the same level as the soil was in the pot, keep the mulch away from the trunk of the grass tree as this can cause fungal diseases.
Lastly back fill with soil and water in. Don’t water the grass head, always water the soil around the base. In my experience you can usually just water them in once and then leave them alone. They are usually killed with kindness more than neglect, unless it is extremely hot weather, you shouldn’t need to water at all.