Mulch can kill trees–that sounds kind of extreme, doesn’t it? But it caught your attention, right? I suppose it would be more accurate to say improper mulching can kill trees, but as I look around me, improper mulching of trees seems to be the standard practice, the only kind of mulching around trees that’s being done.

The previous owners of our new home appear to have paid a lot of attention to detail and tried to rebuild and remodel everything correctly, so the house would endure. They very considerately left behind a paper detailing the house’s history, in which they say that this oak tree was planted in 1885, the same year the house was built:

The flare of this 126-year-old oak tree is buried in mulch

The tree flare is easily visible on this tree growing in the woods without human intervention

How does mulch harm trees?

When you put mulch around the trunk of a tree and cover the root flare, you are covering up parts of the tree that were meant to be exposed to air. The excess moisture can cause rot, but the trunk of the tree is supposed to have access to air, and by piling up mulch against the bark you are preventing this. If the mulch is left there long enough, the tree will try to compensate by growing adventitious roots. Unfortunately, these same roots can wind up wrapping around the tree and girdling it. Figure 11 on this article written by a tree preservation expert illustrates this girdling in progress. The tree winds up killing itself. So we have three ways improper mulching can kill a tree:

1. rot
2. suffocation
3. girdling

In addition, the stress of improper mulching could make the tree more vulnerable to a secondary problem, such as an insect infestation.

Uh-oh. How do I fix this?

You need to remove the excess mulch from around the tree. I’ve started doing that with the oak that I mentioned previously.

I've started to remove the mulch from around the oak tree

So what’s the right way to mulch a tree?

According to Marianne Ophardt, a Washington State Cooperative Extension Agent writing for the Mid-Columbia Community Forestry Council, you should keep the mulch “six inches away from the trunks of young trees and one foot away from the trunks of older, mature trees.” Ideally, the mulch will be in a 2 to 4 inch layer extending out to the drip line, because lawn grass releases chemicals that inhibit the growth of trees. Not many homeowners with large trees want such vast expanses of mulch. Trees can grow in lawns, but more slowly. The most important thing is to avoid burying the tree flare.

Why does this happen?

I can understand why homeowners over-mulch their trees. They’ve heard that mulch is good for plants in general. They know that string trimmers can damage the trunk. But they want to have their lawn looking neat without getting off their riding lawn mowers if at all possible. It seems like the way to accomplish that is to mulch right up to the trunk, and mow right up to where the mulch and grass meet. I guess people spend so little time nowadays around naturally growing trees that the lack of a tree flare doesn’t bother them, or they think it doesn’t matter.

But I have seen plantings of trees around businesses, obviously hired out, that have “mulch volcanoes” around them. You would think a professional landscaper would know better. Could it be that their clients actually prefer the volcano look, and insist on it? What do you think?

Resources Consulted

• Root Collar Inspections
• Rejuvenating Tree Roots
• Mulching Trees is Good and Bad
• Saving the Maltby Oak

………………………………….The curious stranger roves,
With grateful travel, through a wild of groves;
And though directed, oft mistakes his way,
Unknowing where the winding mazes stray;
Yet still his feet the magic paths pursue,
Charmed, though bewildered, with the pleasing view. Stephen Duck, 1731

The hedge clipping was finished yesterday (October 5). We have a variety of hedges here, low, straight hedges of alpine currant (Ribes alpinum) around the Brooder Bed and the Oak Grove and at the Barnyard entrance,

Alpine currant low to the right, Acer triflorum, from Korea and Manchuria, ebulliently orange in left centre, the almost extinguished embers of a northern Chinese rowan, Sorbus pohuashanensis, in the right background. (Photo courtesy Brian Bixley)

About 90' in length, the peonies are interspersed with the white form (easy, tough) of Daphne mezereum. (Photo courtesy Brian Bixley)

The books say that cedar (Thuja occidentalis) hedges should be clipped before the end of July, and I can see the sense in such timing. But like many other garden tasks, we undertake and complete them when we have the time and energy, and few long-term prospects are shattered because of that. July is too hot and, in any case, many of the hedges back densely planted areas where the clipping would involve stepping on and breaking plants that are at their peak. By the middle of September temperatures are cooling and the plants are getting closer to cut-back time, so if I tread on a few it’s no big deal. The alpine currant hedges are clipped several times, especially early in the season when their growth is rapid, but the cedars just once a year.

The Pool Path, with 'Morgan' red maples beyond.

Looking north-east. Prunus maackii in the centre, Viburnum lantana 'Old Gold' on the right. The plan of the maze is that of the maze at Hampton Court in which I was often lost as a child.

I had put away the trimmer and the extension cords, the stepladder with its transverse board which enables me to lean the ladder against the thick hedges without tumbling into them, the sheet I use to catch the clippings and the wheelbarrow for taking them away to be used as mulch, the plank, one end of which rests on a tread of a stepladder positioned in the driveway, the other tucked under the hedge, and which I use to stand on when I am teetering above the slope of the rock garden (“You’ve missed a bit, up and to your right,” says an irritatingly helpful voice), all in a kind of delirious exaltation that the clipping was over for one more year, when I remembered the Japanese yews.

Heading into fall, there are times when we might be feeling overworked, too frazzled, or simply not feeling like doing everything we normally do. Everyone needs to find their own balance in the garden, but you may want to take the time to avoid these common mistakes which can wind up costing you in the long run.       

There will be plenty of time to reflect once the snow starts falling

# 1 – Allowing wet leaves to pile up all over your garden with the hopes that that this will count for compost or winter protection - I’m almost embarrassed to admit that I’ve done this. My garden is near two large Norway Maples, pretty enough trees, but so messy when they drop seeds everywhere early summer, and then finally drop their leaves long after fall leaf pickup is finished. One year I decided to stay warm and ignore the piling up mess until spring. Huge mistake, cleanup was so much worse the next spring as I mucked thru garden beds, needlessly compressing the soil on my quest to rake up leaves. To top it off, voles had run rampant, safely protected by the snow and leaf cover, digging up and eating an entire bed of my favorite hostas. Now, the majority of leaves get saved for my compost bin, and none of them are left to litter the ground like they did that fall.        

Greg Koehler Geraniums

# 3 – Neglecting to divide perennials – No one likes the look of a gaping dead patch in the middle of their favorite perennials; many need to be revived every few years. My favorite perennial dianthus ‘Star’, the ones loved by my daughter because she imagined people being cheered by their bright colors, wound up dying out after several years of brilliance. I was lucky enough to dig up and root some still green shoots off of one, but I’m convinced that I would have been able to save the rest if I had taken the time to dig and discard the dead centers. This was when I was still fairly new to gardening and thought that perennials keep going and going, before I learned that they do better with a little more attention than what I was giving them. My yellow flowering sedum is at the point where I will need to dig and divide; it’s getting too large and developing a yucky dead center. It’s now or never, digging and replanting will allow the roots to develop before a hard freeze.       

Creeping Yellow Sedum begs for division

# 4 – Ignoring diseased foliage - For plants hit with diseases like powdery mildew, it’s important to get rid of any fallen foliage immediately, leaving nothing behind for the winter. Leaf litter is likely to contain the powdery mildew spores, allowing them to lay dormant until spring when it can again ravage your favorite plants. General garden cleanup is a lot of work but will make next year’s garden that much healthier and easier to enjoy. Just a little bit longer and my garden will be sleeping, buried under a nice layer of snow. Then I’ll take the break I’ve been working so hard for, looking back on what’s worked, what didn’t perform as expected, and browsing thru photos of my garden this past season.        

# 5 – Forgetting to shop end of the season at your favorite local nursery – Fall’s a great time for planting, and nurseries offer deep discounts to get rid of excess stock. I’m usually happy saying no to an impulse buy, but if I see something I’ve been wanting for a while, I’ll snatch it up for the right price. I was thrilled to find two toad lillies recently, a plant I’d never grown but always admired for only $3 each. Yeah me!       

Toad lilies find a new home

# 6 – Procrastinating on planting out home grown plants - Even now I’m eyeing up the last pot of heuchera seedlings I have going. The leaf form looks great, and I’m please with how well they did, but if I don’t plant them out before it gets too cold, there’s a good chance that they won’t make it through the winter. I love these little babies, and I’m not willing to take that risk.        

Heuchera seedlings ready for planting

# 7 – Not prepping your clay pots for winter – This is one of my last chores, but with sub-zero winter temperatures, it’s essential. Cleaning, drying and properly storing pots can help to eliminate any lingering disease, as well as ensure they remain intact until spring. I like brushing out as much soil as possible, and then cleansing them with hydrogen peroxide before allowing them to dry thoroughly and storing them in my unheated garage. Storing wet pots can result in hairline (or bigger) fractures as the moisture within the pot goes thru freeze and thaw cycles.     

About the author: Lisa Ueda offers home gardening tips at The Frugal Garden. Her aim is to inspire, awaken and motivate new gardeners into discovering their inner green thumbs.

Five inches of rain fell here in roughly 24 hours. After a multi-week dry spell where my constant promise to my garden was, “As soon as we get some rain, I’m going to…”, it finally rained, big time. Casting an eye at the seasonal clock and acknowledging that we really should have had a frost by now and the whole garden was living on borrowed time, I threw myself into the garden chores like a madwoman.

The Massacre

First up was extirpating the tap-rooted weeds, primarily dock (Rumex obtusifolius), but also mallow (Malva alcea ‘Fastigiata’) and dandelion (Taraxacum officinale). I can remove most dandelions with a long, narrow trowel, but there was one growing through the heart of an iris clump and I was waiting for a good, soaking rain to lift the clump and remove the infiltrator. The dock, I confess, always sneaks up on me. Bitty seedlings one day, foot-wide monsters seemingly overnight. And the mallows are good garden plants gone rogue. By the time I was done, I had left the victims of a massacre in my wake.

The great taproot massacre of October 2010

Wheelbarrow Is Homeless Shelter

Then it was time for “furniture-rearranging.” These plants come out to make room for a shrub. They get moved here, after I pull out the weeds. We’ll add that passalong from my garden buddy, after I take out this daylily, which will go–where?

Rocks, weeds, and homeless plants are the byproducts of a garden bed renovation

Madness Delayed

Yes, it’s raining again, which makes me doubly glad I asked my fifteen-year-old son to remove the sod for a new bed during that sunny period after the deluge. Fortunately the soil was pretty good, because I didn’t have time to amend it, and I’m saving what compost I have left for the roses I still have to plant.

Three planted, a cart-full left to go.

Cape Diamond, purchased from Der Rosenmeister in Ithaca, NY last year

If you’ve been gardening for any length of time, a multitude of these routines accumulate after a while. Often they are based on research, or on the little booklet that came with the plant, or because your dad always did it that way. Follow the same maintenance care for a plant–or a garden–for a decade or so, and I guarantee the “why” of what you are doing, at least for some things, will fade into oblivion.

That’s why we have books like The Truth About Garden Remedies and The Informed Gardener. That’s also why we have search engines on the internet.

According to Rayford Reddell, as alfalfa decomposes it yields triacontanol, which acts as a growth stimulant, encouraging basal breaks. Basal breaks is rosarian-speak for “increased vigor and flower production.” Now, I know I didn’t know that before, but I’m glad I found out.

We usually see the trees budding in early May, not early April

Phenology? What’s That?

Phenology, if you’ve never come across the term, is the science (or perhaps art) of tracking natural occurrences and changes over a long period of time, to discover the patterns and rhythm of them, in order to learn from them. It is one of many good reasons to keep a garden notebook, so you can develop an accurate phenology of your own unique ecosystem.

When You Hear the Peepers, Plant Peas

A sight I never thought I'd see: Cornelian cherry and Juneberry blooming at the same time.

Develop Your Own Very Local Phenology

I didn’t have any garden to-do’s associated with the Cornelian cherry, the forsythia, or the Juneberries, so they’re not messing me up. I do have a good idea of when our last frost is, and counting back from that is probably still the best guide to when to plant things. Of course, the more years you’ve been gardening in the same place, and recording this date, the more accurate you will be. Nature Calendar is an interesting phenological source for those of us in hardiness zones 4-7, east of the Mississippi. If you haven’t spent much time in your present garden, it can help you pinpoint where you are in the cycle of seasons. You can also peruse an earlier post I wrote on phenology, which had observations I had collected from a variety of sources. It frustrated me then, and still does, that many of these maxims either do not agree, or are not precise enough to be helpful. But if you have nothing to go on, they can be a good place to start.

Do you use phenology to direct your vegetable garden planting, or guide you in other garden chores? I’d be interested to hear of your observations.

UPDATE: Just discovered the USA National Phenology Network.

*Quote attributed to Mark Twain

Mud season is capricious; spring-like one week, back to winter the next.

Oh cold climate wise one, Have you seen the forecast for Friday?! Snow and lows in the high teens. What does this mean for all the little perennials I’ve pulled leaf mulch off of? Should it go back on? I’m really looking forward to actual gardening this weekend, but Friday is a bummer!

As I mentioned last year, if you live in a cold climate, you really don’t want to uncover every plant on the first mild day, because, as you’ve discovered, there are sure to be more wintry days before spring is truly here. (Ahem. Do you remember that hard freeze we had in late May last year?)

Clean Up the Pretty Views

The fact is, most plants can grow through whatever mulch or dead plant growth that happens to be laying around. There are two primary reasons for spring clean-up: aesthetics and rodent control. Using this criteria, the first places I clean up are the locations where I know the earliest spring bulbs are coming up. The window of opportunity (WOO) for this is pretty narrow, because before you know it, they are too far along to pull a rake over them. For the same reason, I tidy up the areas I can see from inside the house, so even on cold, blustery days the view outside looks good.

Clean Up the Rodent Hideouts

Here's one example of the vole mischief I find all over my garden in spring.

Search Out and Destroy the Weeds

Of course, the same mulch that protects your garden plants also shelters the weeds. In early spring, I sometimes remove the mulch (or last year’s garden remains), pull the weeds, and put the mulch back. That’s assuming that the soil has thawed enough to remove them, as it already has this year. I avoid stepping on the soil as it is still quite sodden and stepping on it will compact it.

Try Not to Fret

Most established plants in your garden should be fine, covered or not, unless you have a severe case of zone denial, or we get some really out-of-season weather, like that freeze last May. If you have anything that you planted just last fall, or that you especially prize–I’d leave that covered for at least another month, perhaps to the first week of May. For me, that’s four to five weeks before the last frost. Ideally, you’d take it off in stages, but it’s really a judgment call, balancing the time you have, the expected weather in the near future, how far along the plant is and your gardener’s instinct.

In January, the snowdrops in the Secret Garden looked like this:

Snowdrops in the Secret Garden January 2010

Those same snowdrops in early March

Snow melts first around the base of trees, even stumps

The snow melts in damp areas first, though bulbs for this site must tolerate soggy soil.

The south-facing areas amongst shrubs are another good place for the earliest bulbs

Plant some early bulbs by a corner of the house that traps heat.

South-facing areas near pavement are the best of all. Can you see the snowdrops?

Label Your Images

As you may have noticed, these images don’t look like much. If you don’t rename your images, tag them, write captions for them, or whatever your photo managing program permits, you will look at them in July and wonder, “What was I thinking? Why did I take a bunch of photos of dirty, tired snow?” Put them in a folder labeled Plant Bulbs Here and make a note in your calendar to order them in June, when there are discounts for early online orders.

Which Bulbs Are the Earliest?

Of the commonly available snowdrops, Galanthus elwesii is the earliest. Winter aconites (Eranthis spp.) are reputedly equally as early, though they have not been so for me. I am not sure if they are coming back this year. When they like your garden, they really take off. The small species crocus bloom soon after the snowdrops for me. Two to three weeks after the very first blooms, the larger Dutch crocus, the Siberian squills, and the glory-of-the-snow (Chionodoxa) are all blooming. By then it’s a whole different ball game.

Yesterday I told you how I finally realized species tulips planted in the peony bed would help to bridge the bloom gap of late spring. I got the tulips chosen and purchased, and now I’m going to show you how I planted them.

The Smartest Way to Plant 150 Tulip Bulbs

But first let’s talk about the most efficient way of planting them, just so you know my way is not the only or best way. The most efficient way of planting them would be to dig a foot-wide, fifteen-foot long trench some four to six inches deep. Then you would place all the bulbs in the trench, somewhat randomly but more or less evenly spaced. And the truly smart person would have placed a tarp alongside the trench upon which to dump the removed soil, so all that dirt could be quickly replaced into the trench after the bulbs were planted.

The Way I Planted 150 Tulip Bulbs

But I didn’t plant the tulips that way. I knew there were crocuses and snowdrops in the bed and I wanted to save and replant them with the tulips. I also didn’t want to harm any peony roots. Also because of the peonies, I wanted to avoid stepping on the bed if at all possible. I had already seen some red points, the tips of next year’s sprouts, poking through the soil in places.

So, I dug out one square foot at a time.

Yes, I used two rulers to measure a square foot.

This is one of several crocus clumps I unearthed. I also found snowdrop clumps.

I placed ten bulbs in each hole. I avoided straight lines better as I went along.

Not all of the divided bulbs will bloom next year, but in a couple of years each separated bulb will be a new clump.

After I filled in one hole, I would move the farthest tent pegs to mark the corners of the new square and dig again. I did it fifteen times, spaced over two days. As I worked, I wondered if it would look more like fifteen disparate clumps of tulips, or one unbroken sweep. I decided not to worry about that. I thought about how I was being a tad particular, measuring each square foot and counting out bulbs. Oh, well, that’s just me. That’s how I garden. My gardening methods fit my personality and not a work schedule or business plan. It’s also why, I mused, I could never garden for a living. I sleep better at night knowing I saved hundreds of small bulbs worth pennies each, at the cost of several hours of expensive (if I was paying myself) labor. And it will still look beautiful next spring.

How about you? How does your personality show up in your gardening?

After the snowdrops, after the crocuses, after the daffodils, there is just about nothing blooming in the front of the house until the June show of peonies, irises, and poppies. I have not been the first person to notice this bloom gap, not by a long shot, and the traditional recommendation is to plant tulips to bridge this gap.

Tulips As Annuals?

The only thing is, tulips don’t thrive in my clay soil and it’s taken me a while to get used to the idea of planting them as annuals. I have nothing against annuals–when they’re grown in someone else’s garden. In my garden it seems profligate to spend so much money on plants that won’t come back. I used to grow a lot of annuals from seed, but discovered they need the most babysitting (watering, potting on, etc.) right about when I need to spend the absolute most amount of time outside weeding, mulching, and generally asserting a modicum of control. So I tend to grow the kind of annuals that self-sow, which tulips are not.

This spring I finally got it through my thick head that species tulips tend to be more perennial than a lot of the more “woo-woo look at me” sorts of tulips. Here I’d been growing Tulipa bakeri ‘Lilac Wonder’ for over ten years in the Crocus Bank, and it took me this long to realize I could grow it elsewhere. I did realize that the Crocus Bank was not the best place for it. In order for the crocuses to come back every year, we have to let the foliage grow to its full extent and go dormant. And while we are waiting for that to happen, the grass is growing longer, too. Consequently, by the time the ‘Lilac Wonder’ tulips are blooming, they get kind of lost in the grass.

The petite 'Lilac Wonder' tulips got lost in the high grass.

But on the other side of the driveway is the peony bed, which is looking for some action while the peonies get up to speed. A whole mess of ‘Lilac Wonder’ tulips would not get lost with some peony shoots as a backdrop. I had learned from planting the crocus bed that guessing how many bulbs one would need to plant a given area does not always work well. So the first order of business was to measure the length of the bed.

I needed to know the length of the bed in order to order the appropriate quantity of bulbs.

Shopping for Tulip Bulbs

Then it was time to go shopping. Brent & Becky’s Bulbs has the most information packed site. When I checked their information for Tulipa bakeri ‘Lilac Wonder’, it told me I should plant 10 to 15 bulbs per square foot. Figuring 10 bulbs per square foot along a 15-foot length, I could have ordered 150 bulbs of ‘Lilac Wonder’. But I decided to buy 50 bulbs of ‘Little Beauty’, another species-type tulip, and the remaining hundred ‘Lilac Wonder.’ I thought the darker color of ‘Little Beauty,’ mixed in randomly, would add a little zing to the ‘Lilac Wonder,’ and I also hoped the inner color of ‘Little Beauty’ would match the outer petals of ‘Lilac Wonder.’ I’ll let you know next spring.

Here are the tulip bulbs straight out of the box.