I am going to re-pot my now-6.5′ Cedar trees on my open patio. I have – somewhat unbelievably! – managed to keep them alive in small pots for 4 years!!
I have now got them big plastic planters (37cm*37cm* 57cm depth).
1 – the quetsion is what is the best soil for the pots? I have got “100% organic potting soil” which ingredients are: “aged bark, ephagmum peat moss, perlite”.
I have repotted 6 (out of 16) trees so far, and it feels like the soil holds on to the moisture a lot; like the soil is consistently damp whenever I touch it. Will this cause a problem , i.e. root rot, specifically in winter time? (I live in vancouver and it rains a lot here almost year round – maybe except for summer, when i myself water my tress regularly then.)
Should I get some regular soil and mix it with the potting soil I have?
The potting soil looks dark brown and not heavy at all. please let me know if you need to see a picture of the soil.
2 – Also shall I put small rocks at the bottom of the pots to provide some space for water to accumulate/escape? the pots themselves have uneven surface at the bottom which i believe helps with water drainage.
3 – how about putting the trees browned needles at the bottom of the pots? does that help with drainage?
Thanks a lot!
Thank you for your question. We do get a lot of questions about growing cedars and I have included some of our previous responses to answer your questions.
You have not indicated what type of cedars you have but Emerald cedars are one of the most popular. As you know, Emerald cedars are beautiful trees when given the conditions in which they will thrive. Most are grown in British Columbia and will grow well in the B.C. climate with ample water and cooler temperatures.
It appears you have had good success and have decided to repot, but before you do, it’s a good idea to take each plant out of its pot and examine the roots. If the roots are tightly packed and circling around the outside of the soil, it is likely the cedar has been in that pot for quite some time and should be upsized to a pot that is several inches larger in diameter than the current one. Opt for a plastic pot versus clay, as clay pots have a tendency to crack in the winter. Emerald cedars grow a very dense and fibrous root system which will require a large amount of space.
When repotting, loosen the tightly bound roots so that they are more likely to spread into the new soil that will be used to fill the space in the larger pot. Use a good quality potting soil, which you can find at your local garden centre. A layer of small rocks is not required to assist with drainage. This practice is somewhat of a myth and the following article explains the rationale.
Emerald cedars are not fast growers and, with a more limited root system in a container, you should not need to worry about the tree becoming too tall.
A spring application of a time-released organic-based tree and shrub plant food with an NPK (nitrogen, phosphorous, potassium) ratio such as 18-8-8, will offer ongoing nutrition for a few months. Emerald cedars need moderate amounts of moisture and must not be allowed to dry out. Therefore, if you plan on keeping your emerald cedar potted for its lifetime, you will need to pay extra attention to this aspect of care. Regular watering will be necessary – although with living in Vancouver this might not be such a concern.
A layer of mulch added on top of the soil will help retain moisture. It will have a harder time surviving the winter in a pot than in the ground, but it sounds like you have been successful so far. However, we recommend moving it to a sheltered location that has some protection from winter sun/wind and making sure that it begins the winter season well-watered will be helpful.
Good luck.
March 25, 2021