Chad and Jeff’s Excellent Nursery Adventure

About 3 months after I started my job in Minnesota I hired a technician to help me run the nursery and to manage research plots.  His name is Chad and he stands about 6 foot 4, has shoulders that threaten to pop the sides of the skid steer loader whenever he enters it, and he knows his stuff because he needs to (and even if he didn’t know his stuff you’d be scared to tell him that because he looks dangerous with his frightening Fu-Manchu moustache).  Currently Chad is responsible for day to day operations in the nursery as well as writing publications.  In other words he’s indispensible.  When you read a post from me, particularly when it’s regarding nursery or landscape research, you’re usually reading a combination of both of our thoughts.  

Over the years Chad and I have seen a lot of nursery stock; some of it good, and some of it bad.  Between us we’ve seen poor pruning, unhealthy root systems, pot-bound plants, trees planted in soil that was much too alkaline or acidic for them, trees planted in the wrong zone, trees sold that weren’t close to the size that they were supposed to be, trees that were girdled by critters, root systems completely eaten by voles and even a tree shot with a handgun.  I once saw a whole field of Japanese maples topped (basically topping is when you cut horizontally through a trees canopy to give it a flattop – talk about competing leaders and narrow crotch angles!).  Seeing that field almost made me cry – A planting worth $20,000 – $30,000 wholesale almost instantly became worth the price of kindling.  But we agree that none of that can hold a candle to Sara’s Nursery (Named after the owner’s daughter).

I received a call a few years ago from a nursery in western Wisconsin (which, for those of you who aren’t familiar with this part of the world, is much closer to the Twin Cities than to Madison, WI where the University of Wisconsin is).  The caller was very concerned that the plants in the nursery which she had been hired to run were failing.  Basically, their leaves were dropping and she couldn’t figure out why.  This was even happening to plants that we usually consider “indestructible” like potentilla.  I had never heard of such a thing, but it sounded like a soil problem and so I asked her to have some soil tests done and to send me the results.  She agreed, but she was distraught and asked me to come and take a look at her operation.  I balked at first, but after a few minutes of begging I gave in.  I asked Chad if he’d like to join me on a trip to the nursery the next day; he agreed and we were off.

The nursery that we found was a retail operation on a road which was once a major thoroughfare, but had been reduced to a minor highway when the interstate, which ran parallel, had been expanded.  Still, it seemed like a pretty good location for a retail nursery in terms of customer traffic.   After we parked the car Chad hopped out and began inspecting balled and burlapped evergreens while I joined the manager to look at their container stock.  It was a mess.  It was the end of summer when we visited, but the leaf drop made it look as though we were in the late fall.

I popped a potentilla out of a container and could find no roots reaching the containers edge.  Taking a closer look I quickly discovered one major problem.  These were bare root plants planted into containers filled with soil.  Soil is almost never a good thing to put into a container because it’s usually too heavy and prevents air from working its way down to the plant’s roots.  The gentleman who owned the nursery (not the manager – in most cases she just seemed to do what the owner wanted to do) was a farmer who had decided that it made sense to save money by using this soil which grew his field crops so well.   This nursery was buying bare-root plants, popping them into containers filled with field soil, and then selling them at quite a mark-up (by the way, this is considered an unethical practice).

This field soil was obviously a problem, but, while plants usually suffer because of the use of soil in containers, I didn’t think it was likely to cause the carnage that I was seeing.  I asked about their fertilizer and watering practices.  Both of those seemed reasonable and unlikely to cause a major problem.

Meanwhile, Chad came back to report on the evergreens.  Almost all of the evergreens (which showed signs of repeated shearing – good for Christmas trees — not good for the long term health of landscape trees) were missing needles close to the base of the tree and appeared to be suffering somewhat.  I thought it might be a water issue, particularly if city water were being used, and asked where it came from.  The manager told me that all of their water came from a well on site.  In this part of the world we frequently have issues with well water being too alkaline, but it usually doesn’t cause the type of damage that I was seeing here.  I filed water away as a possible, but unlikely cause.

I was pretty stumped, as was Chad.  Obviously we saw problems, but these just didn’t seem sufficient to cause what we were seeing.  The manager offered to show us the potting operation, we followed.  The first thing that struck me about the potting shed was that it seemed old, and yet the timbers themselves hardly showed any rot which is kind of unusual.  We asked when the shed had been built and the manager indicated that she had reason to believe that the shed had been built in the 1940s or 50s.

We entered the shed and noticed a large pile of what we assumed to be soil.  Nothing special.  Then our eyes began to adjust to the dim light and we realized that this was no ordinary pile of soil.  It was mostly white.  We were confused.  The first thought that went through my head was “what is this, cocaine?”  Then I thought, no, it must be perlite.  I looked at Chad.  His eyes were big and round.  I went over to the pile, poked my finger into it, and then touched it to my tongue.

“What the EXPLICATIVE DELETED is this place?” I asked Chad (OK, I may not have used those exact words, but it was something close).  The manager must have overheard.

“Well, it’s a potting shed now, but it was built to store salt for the highway” she responded. “That’s just a pile of leftover salt.  We stack our soil against it when it comes in.”

We tested both the soil from the pots and their irrigation water.  Both were ridiculously high in salt (and, not coincidentally, sodium levels).  In fact, salt levels were high enough in the irrigation water that it would literally burn foliage off of the plants.

Shortly after visiting this nursery Chad became a Buddhist and my beard turned more gray than brown.  I can’t swear that it was this nursery that caused these changes, but I can tell you that I haven’t been the same since.

Eat your veggies! (But not the arsenic, or the chromium, or the lead…)

vegetables_jpg.jpgThe last few years have been a perfect storm for the resurgence of home vegetable (and fruit) gardens.  Grapevines are trellised along sidewalks, herbs replace the grass in parking strips, and tiny gardens of carrots and lettuce are shoehorned into any available spot.  It’s all good  – but we need to be particularly careful about what those plant roots might be taking up along with nutrients and water.


1)  Contaminated soil.  Many urban (and suburban, and even rural) soils are contaminated with heavy metals, pesticides, and/or industrial wastes.  Lead is commonly found in soils near roads (from the old leaded gasoline we used to use) or from old lead-based paint chipping away from houses.   Arsenic is a very real problem in North Tacoma soils, for instance, thanks to the smelter that operated there for decades.   Overuse and incorrect use of home pesticides will leave residues in the soil for years.


2)  Contaminated compost and soil mixes.  Many of the same contaminants mentioned above can be found in unregulated composts and soil mixes.  (More on this topic here.)


3)  Treated lumber.  The old treated lumber (CCA = copper, chromium and arsenic) is no longer being sold, but it’s out there.  These timbers should not be used around vegetable gardens, as they will leach their heavy metals into the soil.  Vegetables vary in their ability to take up and store these metals.  (More on this topic here.)  Likewise, rubber mulches may leach unwanted chemicals into the soil and should not be used around food plants.  (More on this topic here.)

   garden_jpg.jpg    treated%20lumber_jpg.jpg

What can you do to avoid these problems?  A few things are quick, easy and cheap:

1)  Have your soils tested.  I’ve mentioned this in an earlier blog on urban soils.  It’s the best way to find out exactly what you have in your gardens – the good and the bad.

2)  Use only certified composts and soil mixes.

3)  Plant in containers if your soils aren’t safe for food.  This is especially easy to do with perennial herbs, which can be kept like any other container plant on your deck or porch for years.

4)  You can also replace the soil in your vegetable garden.  This isn’t quick, easy, or cheap, but is a solution for some people.

What’s in YOUR soil? (with apologies to Capitol One)

Urban environments are always challenging for landscape plants just because they are anything but “natural.”  Temperatures are higher, water is often less available, and compacted soils have all the nourishing qualities of concrete.  The single most important thing you can do to ensure long-term success of landscape trees and shrubs is to get their roots well established in the soil.

I’m going to leave the topic of soil amendments to another day (but you can find my myth columns about them at under “Horticultural Myths”).  What I want to focus on is our propensity for fertilizing landscape trees and shrubs without really knowing why, or when, or if we should be adding any particular plant nutrient.

The smartest $13 you can spend is to have a soil analysis done before you add anything to your soil.  My favorite soil testing lab is the University of Massachusetts at Amherst.   That $13 will buy you a complete standard analysis of the available nutrients in the soil, plus a measurement of the soil’s organic matter content.  Of course, there are many other soil testing labs you can use, but UM’s Amherst lab is only providing you with information – not a sales pitch for amendments and fertilizers.

Why is this so important?  Let’s say you go to a nutritional supplement store, buy every possible supplement, and take them all.  Do you need all of these?  Probably not.  It would be smarter to talk to your doctor and find out what you’re missing, right?  It’s the same with your soils.  Don’t assume your soil needs a lot of phosphorus, even though transplant fertilizers are loaded with this element.  Non-agricultural soils often contain abundant levels of this nutrient, and too much phosphorus will hurt mycorrhizae and contribute to water pollution.  Take a look at this portion of a soil test for an organic demonstration garden:

Figure 1.  Note the high level of organic material in this soil, which contributes to the nutrient overload.

The trick to fertilizing landscape soils is understanding that landscape soils are not agricultural soils.  You’re not harvesting crops (an activity that depletes the soil of its plant nutrients).  Urban landscape soils usually have high enough levels of most nutrients to sustain plant growth.  But you’ll never know unless you have your soils tested.