Covering of ground below 50foot cedar tree

i would like to know if it’s okay to put more soil under my 50 foot cedar tree so I can plant shade plants under it with rocks for decor

 

The short answer is yes. The long answer is the tree will put roots into that soil, too, and it will very dry because it's shielded from rain. But water it more and be prepared to do it again, next year.

 

You are asking about the locally native Thuja plicata, western red cedar? Yes, this is a wetland adapted species that should have some tolerance for minor grade changes. As might occur during flooding in the wild. But probably best to never bury the trunk of a specimen that has been growing under ordinary conditions with more than a few inches of soil at any one time. And be sure to water the added layer of soil enough to keep the original soil below the new layer as moist as it was before you filled around the tree - the main problem with putting soil over roots of trees in general is that this new deposit suddenly puts the existing root system farther away from fog drip and rainfall.

 

The 50 ft tree is dry under it most of the time unless I water it because the branches and greenery on those branches cause all rain water to drip to the outer edge of the drip line. Should it be watered more than this or is the natural amount from rain which doesn't touch the underside of the trees (branches from the trunk out to 10 feet).?

 

The under side of that tree doesn’t get water unless I water it due to the size of the tree and the length of its branches causing the drip line to be about 10 feet from the trunk.

 

There's a really good reason why people get struck by lightning hiding from storms under great trees. A lot of the rain is deflected by the leafy canopy. It sheds to the drip line. I stand by my earlier post stating that the soil under the canopy of a 50 foot evergreen is often dry as bone and is an impenetrable mat of roots right up to the surface. I invite the world at large to check their own trees a few times and advise just how screwed up I am. I daresay that "fog drip" occurs in very, very few places on earth, and I would question the significance of same, even in BC, about which I know absolutely nothing. I do know a great deal about growing things directly under trees in Michigan. Trees send out roots laterally and feeder roots grow in any direction that favors growth with moist soil, that usually means up from those lateral anchor roots because the top few inches are the most blessed by light rain. Those roots immediately reach into new soils placed on the top of old top as long as that new layer is not so deep that it creates a dry barrier between the rain-moistened upper level and the old, existing layer of feeder roots. It goes without saying that the new soil immediately under the canopy, inside the drip line would need additional water from some source other than the existing rains, etc.

 

Thank you for what felt like a scolding but I’ll accept it as a frustrated answer. I originally asked my question because a person who had no factual knowledge told me I’d kill the tree if I planted anything under it and put large decorative rocks under it as well. I had wanted to make a fairy garden there. Do you know what a fairy garden is? Hopefully you can picture it. I love the cedar tree and don’t want to harm it so if anything I have planned is not suitable then please just explain the reason why without the scolding. I’m an 75 year old gardener who really knows very little about trees. Thank you for your patience.

 

Hello Dolly(online), sorry you felt scolded. I don't think that was the intent, but people with experience like to talk.

I don't think planting some shallow plants or adding some decorative rocks or little elf and fairy figurines would hurt the tree. The key is not to smother the roots and to make sure that it all gets watered. Small ferns or little shade plants can be scratched in with a few inches of soil/mulch added to the top. Don't dig deep. Don't add a thick layer of soil--or anything that might smother the tree roots. I think I know what you mean by "fairy" garden. I saw that done a lot in the redwoods in California. Little miniature gardens with tiny figurines.

 

With filling under trees in general oxygen deprivation isn't the key issue, it's interference with access to moisture coming from above the soil.

 

Yes, little figurines fits the picture of what a fairy garden is about but these figurines can be large as well. Let me spell out what I had planned then tell me what is wrong or right with it. Okay. Here goes nothing or something. All fairy gardens have stationary things which are miniature like houses, small miniature ponds, trellises, fences etc. Plus the animals and people. Usually there is a base made of a variety of materials. I had collected flat rocks which you might call boulders as they require a strong young man to lift and place. ( about 2’ by 2’ and 3-4” thick) . If I place these on the ground under the tree, should they have some spacers under them so they aren’t flat on the ground. The hosta plants would be planted shallowly around the rocks and would be watered. I was going to put white gravel instead of the rocks but it would be messy when the tree drops needles. Instead I would like to fill the spaces between the rocks with bark mulch which wouldn’t look messy with the needles when they fall. Looking forward to your input.

 

Thank you. Can you tell me how much water this tree requires. I have five of them that have pretty well been surviving on rain water until we moved here. I planted some plants beneath the other four and I water those plants but not much as they don’t require lots but wouldn’t be hurt by more if more is required.

 

That sounds like a fun project. To minimize the water blocking effect, I think you want to keep things small. Choose small plants. The 2x2 or x3 foot size of the rock sounds like a large area that would suddenly be smothered and deprived of water. Perhaps smaller flat rocks grouped together, so that water could seep in between them would be a safer plan. Yes, gravel below a conifer is just too messy. Bark mulch is fine, just don't over do it. Keep your soil additions to a thin layer. You will need to add a new thin layer in a few years or so.

 

thank you Eric. Your answers have given me some different ideas of how to go about making this part of my property more inviting and beautiful at the same time plus not hindering the trees ability to receive water from all of its roots. The lady who used to live here never watered the cedars and planted junipers and barely watered them. The junipers had to be dug out and disposed of and in their place I’ve planted a beautiful rose garden which gives me great pleasure. Thank you once again for your patience and answers. Look up fairy gardens on the internet and you will see all kinds from some in small pots to some with faces on the trees to make them look like something from a fairytale.

 

i agree with Eric - those big flat rocks if placed closely and in a large area under the tree will likely change the ground the tree is currently happy to grow in (t0 fifty feet on rain water in the North Okanagan no less)

i am used to gardening in the South Okanagan so I think we have less rain and snow than you up in Armstrong/Enderby

I am also familiar with coast gardening - and lots of red cedars - and in these days of building houses everywhere - they clear the land - grade the soil - "save" a few cedars from what used to be the forest of cedar/maple/alder etc - and then in a couple of years, the dead foliage starts to appear on the cedars - basically by disturbing (grading) the soil and other changes - the subdivision has killed the cedars. These trees look tough and sturdy and seem to grow everywherer - but are surprisingly specific in their habitat requirements

maybe you can make your faerie garden more of a woodsy mystery rather than lots of imported rocks of any dimension ---- if you need rocks - then just a few - and also you you could make some height by setting up the random shape flat rock so it's vertical rather than horizontal (it looks big and yet is still lift-able by one human)

QUESTION - do you see hostas in that part of the Okanagan? do they survive the winter? I know at the coast they do well in dry shade

one plant that might help your faerie theme is "maidens bower" - it grows wild in the moist shaded forests near penticton ---- some might call it invasive - I don't have trouble with it. If you like more color - then some sort of Clematis in the Alpina style (the blue drop down flower then it gets fluffy seed heads) would look nice - remember that Clematis like shade roots and sunny heads - and you can't dig around or disturb them --- and they need water

maybe some cyclamen? they again take time to establish - and most of the year are "boring" - however - they surprise you one day (spring or fall)

I have a clematis montana (pink) that grows up in to a red cedar - it's at the coast - and no it does not harm the cedar (unlike Ivy) ---- i am not sure if that clematis can livie n your climate. Once the clematis was established - I never watered or pruned - nothing. They go dashing up toward the sunlight - so again, shaded roots and sunny faces. You probably should think twice before this idea .... my garden came with it !

you could likely do a lot with decorative pots (they make frost-proof fibreglass etc) - for your hostas and seasonal color like impatiens or .... how about a little ornamental maple in container? that could be a nice part of your faerie theme (there are also some small philadelphus (mock orange) that go in containers too.

by using container - you're creating a micro soil environment for the faerie effect you're aiming for - and then you just water and feed your containers by hand - and - best of all you are NOT digging around your tree or amending the earth it is happy in already

please don't plant ivy - you may well regret it

there used to be a book about gardening in the Okanagan written by a scientist from the big Ag Canada research station in Summerland nr Penticton. It is probably at the Ok regional library system
https://www.amazon.ca/Gardening-Okanagan-book-local-gardeners/dp/B00B18TSVW

I"d also look up the good old Sunset book of western gardening (there are many editions over the decades) - look up one of the zones (they have a proprietary zone label system) that is similar to Enderby Armstrong and see the plant lists

also - as everyone in BC knows - make sure your garden materials and style are fire smart ---- wild fire is a risk as anyone in the Okanagan realizes FireSmart - Province of British Columbia

 

Thank you for all your input. I really appreciate it. I will look for those books. We have a couple of second hand stores that have a large selection of gardening books that are cheap to buy and we also have a small library. The cedars are sure getting their water this month. It is raining again today. Hopefully we get a couple of days a week of rain to prevent fires from starting up. The clematis sounds intriguing but they wouldn’t get the sun unless I took off some of the lower branches. That would be pretty though. Thanks for the thought. I’ll investigate that.
It is warm enough here that we have yucca plants that thrive and some outdoor cacti.
Have a great summer.

 

Hello Dolly (that’s fun to type !)

I was thinking more about your faerie garden ... and I think some dry shade ferns in containers (that you can water / feed without changing cedar tree roots ) might be a nice way to « set the scene » in your garden

You’d have to look around and observe which plants live over your climate winter in containers (a different consideration than plants in the ground )

Have a look at this xeriscape group website because at the coast or in the Okanagan —- summer water for plants is in short supply - and there is a handy plant reference w photos etc

www.okanaganxeriscape.org

Also - fr a design point of view - i suggest you - start w matching frost-proof pots of diff sizes I think (sets your theme)

.... then there’s another old garden « rule » that says if you don’t know what to plant to fill in a spot on a border or patio ... plant another of what you’ve already got (ie repeat )

This sounds boring but it sets the stage then you bring in your faerie buildings and people ... and maybe some summer accent plants for color ... otherwise it can look like a garage sale jumble!

Speaking of which - thrift shops are great sources for little faerie size accessories

And remember to put a comfy place for you and your tea cup to relax and view your faerie garden

Maybe you have young guests who’d like to have a tiny seat in your garden too

(Édit to correct the URL linked above)

 

Such great ideas. I can’t use pots that would freeze because they would split from the moisture freezing and I want to use some hostas and ferns so I will plant them in shallow holes carefully while trying to avoid cutting the roots of the tree. I also bought some very young lavender plants and they can withstand the drought so not getting much water won’t hurt them. I was not able to do anything today as it rained most of the day. I’m sending a sample of the approx. size of what.my fairy garden will look like. The characters will be larger than the real little fairy gardens have.
I’m going to Bremerton Washington to visit friends this week or next so hope to find some neat characters there.
Thank you for your helpful suggestions.

 

I'm not offering any help here, just offering a photo of a little guerilla fairy garden at a Parks Board's walnut street tree in my neighbourhoood.

 

Great inspiration both posts

I like the guerrilla faerie concept ! The good things in life are often fleeting and unexpected , right?!

DOLLY for sure - when in USA - look for solar string and other garden solar at target etc because maybe you can enhance the night life of this faerie village!

What fun ....look fwd to photos of your garden

 

I'm weighing in late to this conversation and don't have much to add to the thoughtful advice you've been given previously. From my experience planting under 4 100-foot Thuya plicata in Burnaby BC, there are lots of plants you can grow beneath them provided there is enough moisture. From what I read, Enderby has a fairly consistent rainfall throughout the year which is a huge advantage. The climate is changing however.

Where I live now in the Parksville area of Vancouver Island, almost all the native cedars are dying or dead. My advice would be not to add any stress to the cedars in your garden - whether it be adding additional soil, disturbing the soil to plant in or even placing rocks or pots under the trees. Encourage them be as healthy as they can for as long as possible. Treasure them. You just don't know how long they will continue to benefit from the same annual precipitation as you have been accustomed to.

 

Thank you for your input. I have planted blueberries in a space between the cedars so they are in a spot with acidic soil and good sunshine and I supply them with water over and above the rainfall, so the cedars get extra water during dry spells. My concern was to be able to plan a fairy garden under the one cedar which is closest to the grassy area where we entertain friends and family. I think I have enough information from two other responses to aid me in the planning. When I’m finished I think the cedars will be happy with the choices I make, and I will also be okay with it. Again, thank you for your input. I wouldn’t do anything purposefully to harm these beautiful giants, and now I have great info to enhance their lives while giving us a neat decorated area that does not hurt them.

 

What a neat idea and likely less cost than up here in Canada. Thank you for that interesting and exciting idea. Now I have some super shopping ideas. So looking forward to my summer shopping.

 

Thank you. There are so many interesting ideas out there and what I decide upon will depend on what I find while in the USA. Again thank you for your photo. Pinterest has a huge selection to look at as well.

 

Will post once I have it completed.

 

Dolly - Target and the other big box tend to get the summer patio / garden solar "going going gone" asap -

so maybe pre-shop online and have it sent to a store for pick-up (like Wenatchee - I think there's a location - I usually go to Bellingham or a location in Oregon)

make sure you get your computer to go on to the USA Target (not the international "ship to Canada") - basically there are a couple of clicks (shop in US funds and ship to USA) you make at the top of the page then it will let you in to USA Target.com

that said there might be some fun garden solar items on Cdn Amazon or at a nice garden center in your part of the province - sometimes you can find them at good ol' London Dr*gs in the seasonal aisle. (probably on sale by now to make room for "back to school" inventory)