Mulch Volcanos or How Not to Plant Trees

It seems a lot of people and/or landscapers are under the misapprehension that when it comes to soil, more is better. This is not always the case.

In my neighbourhood

In my neighbourhood.

This volcano of soil is doing a couple of bad things to this poor rhodo. Firstly, stems and trunks should never be buried like this. DSCN2343You’ll see more of this in the next few pics. You should always see the root flare at the junction between the stem/trunk and the soil. You’ll see “bell bottom trousers”.

Here’s a beautiful Blue Spruce in excellent condition

Blue Spruce in the neighbourhood.

LOVE this tree: Blue Spruce in the neighbourhood. You can just about see the root flare if you click on the image to enlarge it then click again.

Secondly, rhodo roots are even more shallow than other woody plants, so adding ANY soil on top of the planting area is going to make your rhodo suffer–from too much moisture and too little oxygen.

Very sad little rhodo in a brand new planting bed--the duplex was just finished in the Fall.

Very sad little rhodo in a brand new planting bed–this duplex was just finished in the Fall.

You can and should still mulch rhodos, just several inches away the the trunk, and only about 2″ of nice light mulch (wood chips or well composted compost), not soil.

The Problem:

Also my neighbourhood.

Also my neighbourhood.

Exactly the same thing above–soil (or in this case bark mulch) mounded up around the trunks of these Thuja (arborvitae).  This causes a number of problems: Too much moisture against the trunk will invite disease and bark splitting. It also promotes root girdling, which is when roots start following a circular path around the trunk instead of heading out perpendicular to the trunk. As those roots grow and fatten they will often pinch the channels that draw water, oxygen, and nutrition up the tree. Root girdling is a very bad thing for your tree.

DSCN2374DSCN2375Two views of the same tree. Here the planter put a rodent guard around the base of the tree, which will also also help reduce moisture against the bark. But the roots will still opt to grow up into the volcano soil causing the root girdling again. And then to hide the look of the mounded soil, they planted creeping raspberry (Rubus pentalobus). In other circumstances I’d say this was a good plant for under the tree, but it will hold the soil there (eroding away would be a better thing) and act like living mulch, which will just exacerbate the moisture problem. (It’s a pretty vigorous plant in coastal BC and will begin to take over the lawn area–not a bad thing maybe.)

I plan to write discreet polite letters to the owners of these trees and shrubs offering to help remediate their plantings. Hopefully they won’t be too offended at the local busybody who thinks she knows everything!

Love to get your comments and questions.

How to Capture Morning and Evening Light

How to use morning and evening light to your best advantage

It’s late October, but still a great time to be planting here in coastal BC. And one of the things I’ve loved about my own garden is how I serendipitously planted some shrubs and perennials where they’ll GLOW in morning or evening light. And of course, since it was serendipity–read “total accident”–I missed the opportunity to do the same with others. No problem, my “research” garden is always in the process of change-I love to dig things up and move them around. They seldom mind.

Here’s some examples:

Imperata cylindrica, Japanese Blood Grass:

This is what it should look like in your garden


You can see that the light is shining through from the back right (shadow front left).

My JBG on the other hand looks like this:

Not taking advantage of this glorious sunny day, just kind of ...dull

Not taking advantage of this glorious sunny day, just kind of …dull

So it’s going to be dug up, divided, and moved to here:

DSCN1052In among all this lily-of-the-valley, I’ll put clumps of JBG. What a fabulous combination when morning sun shines through.

Japanese Maple:

Morning sun front-lighting this Japanese Maple

Morning sun front-lighting this Japanese Maple

This Japanese Maple–almost overpowered by the Pieris japonica–is beautiful from the street side. But from the house side (not my house)…


I know you’re confused–“Where’s the Pieris?” This is actually a different tree, same property.

…it’s practically on fire! And because it’s out toward the street giving enough open space on all sides, the evening lighting will be even better.

Euphorbia characias is an amazing structural plant:

Thanks to HortusUrbanus for her Seattle picture

Thanks to HortusUrbanus for her Seattle picture.

But if you situate it where there is open space between the viewer and the morning or evening sun, you get this:

DSCN1007How about this Fritillaria meleagris

Fritillaria meleagris

Fritillaria meleagris

DSCN1006Or even

Even your teeny tiny botanical tulips.

Even your teeny tiny botanical tulips.

Then there are things you can’t control


…but keep your eyes open, and appreciate them when they appear.

How to

The key is just identifying plants that will show extra-special when backlit–either flowers or foliage, like the lily-of-the-valley above–and then plant them so they are positioned between you and the early morning or late afternoon sun. (These are mostly early morning pictures, but late afternoon sun gives even more fiery effect since the angle of the sun produces that golden glow.) Make sure they’re planted with open space, or lower growing plants, on the “sun-side”, so your targets plants are not in the shadow of the others.

Then go out and enjoy the view. Take pictures. Send them here. I’d love to see what others have done to Capture the Light.

So You Bought a Shrub, Now What?

It occurs to me that people may be a little unclear about what to do with that cute little plant you just bought/received/acquired. I mean, how hard can it be? 1. Buy. 2. Take out of pot. 3. Put in the ground. 4. Watch it grow.

Well, the answer is, pretty much not hard at all. As long as you’re aware of a few things. As with all living things, the plants you plant in your garden need three things: water, air and food.

Container Grown Plants

Plants that are container grown start as a seed or cutting, or in many cases nowadays, tissue cultures. Once they get to a certain size, they are transplanted into a larger pot that is  suitable for sale. The plant company may then decide to grow the plant, then transplant it again into a larger pot so that it can be sold for more money. Say the difference between a 4 in. pot selling for $4 and a 6 in. pot–a 1-gallon container–selling for $15. It would probably take the best part of a year to get from the seed or cutting or tissue culture stage to a 1-gallon container pot stage.

Always Check the Roots

Now suppose the plant company put that 1-gallon container plant out the day after it was transplanted from the 4″ pot. It would still be a $4 plant now selling for $15. You can tell that by looking at the roots. Can’t see the roots through the solid pot? (What, don’t you have x-ray vision?) So you carefully tip the plant out of the container to see what the quality of the roots are. If you’re a little squeamish about doing that at the garden centre (or Home Depot), you can get a sales staff to do it for you. (And if they won’t, DON’T BUY THE PLANT!) If you don’t see any roots at the edges of the soil, you are paying a 1-gallon price for a 4″ plant.

But on the other hand, suppose the plant company didn’t deliver all its 1-gallon plants this year, and they have to hold on to them until next year. Now you’ve got nice healthy plants growing in a small cramped environment. For a while the plant will be fine, but time will come when it’s beginning to use up the available space. Now it’s going to dry out faster, and the roots will run into the edge of the pot, and start to travel around the outside. So when you check out the roots, if you see them travelling around the edge of the pot, DON’T BUY IT. If it’s the only one there, and you really want it, show the sales staff what you’ve found and make sure you get a discount. (That’s frugal Janet talking!) And when you’re about to plant it, cut through the roots in quarters along the length of the root ball.

Thanks to Henny Penny Rose Cottage for this great pic of root bound plant!

Thanks to Henny Penny Rose Cottage for this great pic of root bound plant!

If you plant the plant like you’ve received it, the roots will continue to grow in the direction they’ve started and will never support healthy growth. It’ll die.

As I often do, here’s a link from Linda Chalker-Scott about plants that are root-bound in their pots. LCS would recommend you actually wash the rootball. I haven’t tried that–I should try it in my research garden!

How Deep?

Hardy Hibiscus (Hibiscus syriacus) planted high--you can see roots at the base going into the soil.

Hardy Hibiscus (Hibiscus syriacus) planted high–you can see roots at the base going into the soil.

Most plants should be planted at the same level that you find them in their pots. You take it out of the container, put it into a hole that is dug just about the same depth as the rootball, and then backfill the space with the soil you dug out. Definitely trees and shrubs should be planted this way, some perennials can go deeper, and roses can go as deep as you like. (In Ontario I’ve heard recommendations to plant roses 6″ deeper that you find them in their pots.) You’re going to dig only as deep as the rootball, but much wider than the rootball. This way there is lots of loose soil for the roots to travel sideways. And the soil is the same as you dug out, so there’s no “soil interface” problems. That’s when the soil your plants have been living in and the soil you’re planting into are so different the water doesn’t travel from one to the other. Adding compost or manure or something else to the backfill soil (“amending the soil”) will cause a “soil interface” problem. Now you can certainly “top-dress” the plant–a couple inches of compost on top of the soil, away from the stem/crown/trunk of the plant–and the earthworms will work it into the soil.

A couple honourable mentions: Rhodos root very superficially, so you can safely allow the rootball to sit a little higher in the ground than the grade around. And tomatoes should be planted deeper that in the pot–cut the bottom leaves off, with only 4-8 leaves remaining at the tip, and then plant deep enough so that the whole bare stem is covered. The stem will root all along it’s length giving you a great root system.


Water your plant a lot. If you’re planting now, it’ll be drying out pretty soon, and your plant will need lots of additional water that you will have to supply. On the other hand, if you don’t buy that plant you want so much until the fall, the cool weather will be easier on the plant, the lack of freezing will allow it to grow roots before it gets too cold, and the rains will do the work of watering so you won’t have to. In coastal BC planting in the fall is the best, and we can do it pretty much up until Christmas! If it’s an “herbaceous perennial”–which means it will die down over the winter and grow again in the spring–make sure you mark where it is so you don’t walk over it, dig it up by mistake, or try to plant bulbs there.

Final Link

I enjoy reading Doug Green’s Garden posts, and today on FB he steals my thunder.

As always, please comment, questions, refute (nicely), share, or otherwise leave feedback.

Unrelalted picture of Aquilegia--Columbine. Very shade tolerant!

Unrelated picture of Aquilegia–Columbine. Very shade tolerant!