Overwintering Eucalyptus in Treasure Valley Idaho zone 6b-7a

Eucalyptus plants along with the blessings and troubles that come with overwintering it has been a year in the making. 

These seeds were selected from a farm deep in Australia in August 2023.

Once they arrived in Idaho, I had little hope they would survive  their first winter, but surprise of all surprises, those tiny seeds not only sprouted by November, they began to grow. I was left with hundreds of plants that my tiny gardens could not support, so I offered these 6"-10" seedlings to other brave souls in the Valley who wanted to give growing them a try. 

Before we get into the overwintering process I plan to do, let me talk about how the way I have grown them.

The seedlings I kept for myself were split up into three groups to see how they fared in various environments.

The smallest group stayed in pots smaller than 7" in my greenhouse in warm conditions where I could make sure they were watered daily and received consistent babying and care.

The second group also remained in the greenhouse with the same careful protection, but were given large 3' wide and deep pots to grow in.

The third group was the largest group by far. Over 100 plants were placed outside in a newly created bed in a back garden that used to be a chicken run. I mention this because there was probably residual fertilizer that didn't exist in the other two scenarios. 

Five months into growing these seedlings on has given very different results. 

Group 1 was the least productive. The plants never grew more than 14 inches tall. They were spindly and struggled with gnats which I treated weekly with Neem oil. I will not be protecting these plants through the winter.

Group 2 in the large pots grew much better. They actually have a bit of bulk and height to them. Although they are not large enough to cut from, I will be cutting back their central stem and covering through the winter and keep them inside the greenhouse with minimal supplimental heat.

Group 3 I would call a Blazing Sucess! These plants seemed to thrive in their new garden bed. They are easily between 36"-48" tall with quite a bit of bulk to them.

These have produced so well that I have been able to share stems of fresh cut Eucalyptus with it's glorious fragrance with fellow eucalyptus lovers. There are still a few bunches available (as of October 14, 2024) and can be purchased here.

This Group 3 will get the most protection and attention through the winter in hopes of having even more fantastic eucalyptus to share next year.

This is the process I plan to use.
 1- Top all main stems down to 6" above the ground. There may be some side shoots that are lower than this 6". I have read that this can be useful to the plant come Spring, so I will leave them on.
2- The entire bed will be covered with leaves.... many leaves... multiple inches of insulating leaves to protect the roots during any hard freezes we receive over the next 7 months.
3- To keep the leaves in place, I will be covering the entire bed with agribon fabric. This allows both rain to filter through as well as snow to melt and nurish those little plants.
4- Come Spring, once all danger of frost has finished and the ground has warmed more than 50 degrees, I will remove the fabric and leaves and check for the progress.

The rest of the story will have to be told this coming Summer in 2025. I am as curious as you are to see if there will be continued success for these glorious plants to survive in our mild, but occationally harsh Winters.

Thanks for following along on this journey!