The Garden Professors™ – Page 53 – Advancing the science of gardening and other stuff since 2009

Random acts of horticultural violence

I’ve been traveling in Europe the past few days working on a project with some colleagues in the Czech Republic. While we typically think of our friends in Europe as being more progressive and cultured than us, it appears there are still a few areas where they have a ways to go – such as banning smoking from restaurants and bars – and in learning about the art and science of Arboriculture. (And before the hate mail from Europe starts pouring in; yes, I realize we can find plenty of scenes like this in the US – just hoped I’d find better on this side of the pond).

I’m not a big Forsythia fan, but really…?

Not sure what the desired outcome is here.

This is a black locust near Prague castle. Black locust, which is native to North America, was introduced to Europe for forestry planting in the 19^th Century. The trees were extremely well adapted and have become invasive in many parts of Europe, out-competing native trees and suppressing the development of understory plants. This particular specimen is one of the oldest in the Czech Republic, which presumably is the reason it has been allowed to linger on. A good example of when a tree’s quality of life has run its course. It truly pained me to look at this tree. And, of course, in the U.S. the tree would probably have been long gone due to liability concerns.

The tree is mostly hollow and was once cabled together. The cables were removed after the tree lost its tops in a storm 20 years ago.

It appears that the tree’s principle function these days is feeding woodpeckers.

OK, in the interest of international diplomacy, something Europeans get right is pollarding. In the U.S. what is passed off as pollarding is usually just topping. But when it’s done right (in this case with horseschestnut) and in the right setting (Prague Royal Gardens) it can create a striking effect.

Valentine’s in May

Lamprocapnos spectabilis (the species formally known as Dicentra
spectabilis) is an easy, tough, arctic-hardy, spring-blooming perennial
that always makes me happy. I’ve posted previously about the wonders of
‘Gold Heart’ – all the screaming yellow foliage you can stand, topped
with magenta flowers.

Last fall, I’d finally gotten my mitts on a hard-to-find one named ‘Valentine’. Already dormant in the pot, I planted it with hopes that it would somewhat resemble the tag photo (and hype) as I’d not seen it in person. What a treat when it finally unfurled last week…woo hoo!

Pride of Place Plants is the introduction and marketing firm (“plant sports agents” as I call companies like this. Pun intended). According to Pride of Place, ‘Valentine’ (USPP22739,COPF etc.) arose as a chance seedling in the garden of Phyllis and Lyle Sarrazin, Prince George British Columbia, Canada.

This is a true “color break” for the species. The heart-shaped flowers glow fluorescent red, and the dark red stems really pop against the rest of springtime’s green. Keep it away from pink stuff, though. Yeek.

Possibly available at a fine independent garden center near you; or through mail-order – I know Plant Delights Nursery carries it.

What’s in the Worm Juice?

A couple of weeks ago I mentioned that I would be taking a look at the leachate that comes from vermicompost. Here is the worm house, owned by Master Gardener Meleah Maynard, from which this leachate came. This is a picture from when the house was new — it now has multiple floors.

It has been running for a few years now, and the “ingredients” that she puts in, mostly table scraps, are pretty typical of what anyone would put into compost. She reports that it produces about a gallon of leachate every 2-3 weeks. The leachate from this house has the following properties:

pH – 8.5: That’s a high pH for soil, but for a fertilizer added every week or two it’s fine.
Nitrogen – 1120 ppm: That’s high for a fertilizer. About twice the concentration I’d use if I were applying a liquid fertilizer to my plants at home. The nitrogen is present mostly as nitrate, which is a good thing. If the nitrogen were present primarily as ammonium, that might cause problems.
Phosphorus – 22 ppm: That’s a good/appropriate concentration of phosphorus for most plants. It’s much less than we apply when we use a typical garden fertilizer. Potassium – 5034 ppm: This is an order of magnitude higher than we’d apply for most plants using a liquid fertilizer.
Calcium – 279 ppm: This is a reasonable amount of calcium.
Magnesium – 211 ppm: This is reasonable amount of magnesium.
Sodium – 634 ppm: I’d like to see less sodium, but this shouldn’t cause a major problem.
Other elements present included Iron, Copper, Manganese, Zinc, Molybdenum, and Boron, all at levels less than 1 ppm.

So what’s my conclusion? I think that, based on the nutrients and nothing else (no trials), this could be a great liquid fertilizer if it were used properly. I’d recommend diluting it somewhere between 1:1 and 1:5 worm juice : water before applying it, and I’d only apply it once every week or two. If you want to use it, try it on something that you’re not too concerned about first, just to make sure that it doesn’t do anything too terrible (It shouldn’t, but I believe in caution).

A Real, Live, Learning Experience

What a crazy spring! But it finally, finally came here to the Blue Ridge Mountains (Linda Chalker-Scott refers to them “speed bumps”).

My Ornamental Plants Production & Marketing class has been at work since early February, growing plants and marketing them at the Hort Club Plant Sale as part of their lab experience. Of course, they are completely at my mercy as to what they get to grow (bwuhh ha ha *evil hand wringing*). And due to their professor being a complete plant dork, they wouldn’t know a potted mum if it hit them upside the head. Not that there’s anything wrong with mums. But with so much fabulous stuff to choose from – they can just look that mum crop protocol up in a book if the need arises. They do get to experience a few zonal geraniums, but that’s only because the University’s past-President buys 50 red ones from us every year.

So what do they grow? Fabulous goodies you could never, ever find at a garden center in SW Virginia. Variegated Manihot esculenta. Dr. Cho’s newest Colocasia ‘Black Coral’ (gloss black with deep blue veins). Awesome landscape begonias such as ‘Gryphon’ and ‘Santa Cruz Sunset’. Fun annuals like Torenia and Osteospermum. Fifty-two different things – fairly ambitious, considering there are only 11 students. We fill a 40′ x 80′ house plus two “research” greenhouse sections that I commandeer the moment they come available.

My production students always start out the semester rather tentative, and then get more engaged as time goes on. We do a 2.5 day field trip across the state to visit top greenhouses, nurseries, and garden centers in early April. My gang comes home with a real appreciation of the hard work and long hours required to be successful; more important, perhaps, is their exposure to the tremendous passion and enthusiasm of the people in the business, many of who are alumni of our department.

SO…thirteen weeks later, we have greenhouses crammed full of really great plants,a bunch more ordered in from top area nurseries, an enthusiastic mob of customers with pent-up plant lust, and some very proud students.

And that’s the best part – the students get to/have to work with (gasp) the PUBLIC. Very disconcerting for some of them. The Plant Sale Chair for the club, who is also in my class, is a terrific student but a bit shy. Of course, he got the loudest customer of the day. She hollered “Hey, boo boo! Tell me about this plant! Sez here you grew it!” Ten shades of red later… I thought he was going to faint. But he did regain his composure and helped her with some other things. He also made me promise to never, ever tell his classmates what she called him.

But you’re not in my class 😉

Here comes “boo boo” with his very nice Cissus discolor (Rex Begonia Vine).
Names withheld to protect the totally embarrassed.

Pocket parks and urban corridors

As you may know, I spent most of the last week in Charlotte, NC. On my last night, I got to visit uptown and enjoy the pocket parks along Tryon Street. Here’s one of them at the intersection of Tryon and Trade:

It has a lovely water feature – it was a warm day and the breeze from the fountain cooled the air off significantly.

A little further on was this plaza, featuring jasmine-covered “umbrellas”:

The umbrellas were actually sculptures – little works of art on their own:

The nicest things about the uptown area were the wide streets and equally wide sidewalks. Lots of light could get through these urban corridors, supporting a canopy of willow oaks:

This is an urban area that not only invites pedestrians, but treats them to a botanical experience that unfortunately isn’t common in our cities. Hopefully this is the future of urban greenspaces…and not just a delightful anomaly.

Spring fever: Conifer style

We finally got a reprieve from our wet, cold weather. Just in time for the annual inspection of the conifer troops at the Harper Collection of Dwarf and Unusual Conifers at MSU’s Hidden Lake Gardens. One of the interesting things about making repeated trips to a conifer collection like this is that different conifers stand out each time. Whether due to lighting, background foliage, your mood, whatever; it seems like there are different stars each time.

Here are some of today’s standouts.

Pinus contorta var. latifolia ‘Chief Joseph’
‘Chief Joseph’ lodgepole pine. Discovered in the wild near Joseph, Oregon where Chief Joseph, leader of the Nez Pierce once lived.

Abies concolor ‘Blue cloak’
‘Blue cloak’ concolor fir (white fir for people living on the West coast). One of the most intense blue forms of color fir – rivals virtually any Colorado blue spruce.

Sciadopitys verticillata ‘Joe Kozy’
‘Joe Kozy’ Japanese umbrella pine. Sciadopitys is one of the most primitive forms of conifers with fossils dating back over 230 million years. This cultivar was selected for its fastigiate growth by Sidney Waxman at the University of Connecticut.

And, of course, they always look great when you put them together. For more info on these and other conifers check out the American Conifer Society Conifer database.

It’s raining, it’s pouring, it’s a good time for a site assessment…

April is turning out to be a soggy month for most of Michigan and our surrounding states. While most homeowners are inclined to hunker down indoors and keep an eye on their sump pumps on these dark, dreary days; our current run of wet weather is a good opportunity to take a stroll around your property and make some notes. In particular, note any areas where water is accumulating.

Poor drainage is one of the most common sites factors that limit landscape tree and shrub survival and growth. Sites that retain water for more than a day or too after rains stop are especially problematic. The challenge with wet areas is we usually wait to plant trees and shrubs until things are high and dry and it’s easy to forget where the wet spots are.

There are two primary strategies for establishing healthy trees and shrubs in flood-prone spots. First, determine if the problem can be corrected. In some cases homeowners may be able to re-direct water flow from downspouts or other sources to keep water form accumulating in one spot. Again, these kinds of problems are easiest to spot if you go out when it’s raining. Re-grading the area or installing drain tiles are other options but these are usually require skills and equipment beyond the average do-it-yourselfer.

If correcting the drainage issue is not an option, the second strategy is to plant trees or shrubs that are tolerant of flooding. Plants vary widely in their tolerance of soil flooding and, not surprisingly, trees and shrubs that grow naturally along riverbanks and other low areas are usually the most tolerant.

This low spot in my yard was a good site for a Baldcypress

There are numerous resources on flood tolerant trees and shrubs on the web. Two of the better resources are from the Morton Arboretum and from Cornell University. Please note the Cornell guide is a large (>6 MB) .pdf file.

These Michigan holly (Ilex verticullata) I planted a couple of years ago a doing fine even though they are periodically flooded each spring.

Wet areas on your property do not have to be a ‘dead zone’, but establishing trees and shrubs in low laying areas takes some planning. The first step in the process is assessing your site and identifying the problem areas. The best way to do this is to put on a raincoat and take a walk in the rain.

Applying pesticides when you don’t mean to

I’d rather we didn’t use them, but I see their value and I appreciate what they can do for us when they’re used properly. One of the things that I hate about pesticides though is that, even when they’re used correctly, sometimes they can come back and hurt us in ways that we don’t expect. You have probably heard that you should not use grass clippings where herbicides have recently been used as a mulch because they could injure them. This is mostly because of the pesticide 2,4 D and other, similar herbicides for the lawn which can injure other plants if placed in the wrong spot.

Back in 2011 the herbicide Imprelis was used on many yards, especially in the Midwest, and did a lot of damage to spruce and other trees as Bert has mentioned in previous posts. We had thought that we were nearing the end of the effects that this herbicide would have, but now I’m not so certain (see Bert’s post from March 25). Recently questions have been asked about whether this stuff might last longer than we thought in compost. A few months ago I probably would have said that I doubted that Imprelis would linger long in compost, but, in part because of how long its effects take to show up on some plants, now I’m not so sure, and there are others who share my concerns (in fact, it was these guys who pointed out the possibility of compost problems with Imprelis to me). I honestly don’t know whether compost that includes trees that were treated with Imprelis (or has Imprelis in it for some other reason) would or wouldn’t be harmful to other plants, but I do know that it’s something I’d be watching out for.

Protecting plants from frost

What a difference a year makes. This time last year our growing degree day accumulations were nearly a month ahead of normal and we had already experienced temperatures in the 80’s, with more than a week straight of 70 + deg. temperatures. This year, of course, is a different story. But spring will come eventually. As trees and shrubs begin to leaf out or we get antsy and begin to plant annuals, we need to be prepared for late frosts.

Searching on the internet for ‘plant frost protection’ will yield a wide array of strategies for reducing frost damage. Some strategies such as frost irrigation or wind turbines are mainly geared to commercial horticultural operations such as orchards or nurseries. Other techniques such as a various spray-on products usually provide only a few degrees of protection or are variable in their effectiveness. For homeowners, the most effective technique is the ‘old tried and true’; covering plants loosely with a bed sheet or similar lightweight fabric.

Photo: gardeingadvice.net

When covering plants for frost protection it is important to remember the basic principle at work here. Late frosts typically occur on clear nights. That’s because the lack of cloud cover allows heat from the earth to re-radiate into outer space. By draping a sheet or other lightweight covering over plants, the radiant heat from the ground is trapped, preventing plants from freezing.

I bring this up because I have seen several forms of ‘plant protection bags’ currently on the market. In terms of protection from late frosts, these are more likely to turn out to be plant body bags. Some of these bags are designed to gather at the base; sort of like putting on a coat. This is another example where making analogies between human function and plant function falls apart.

Remember, the point of covering plants is to trap the earth’s heat, not the plant’s heat.

More importantly, frost cover protection needs to be removed each morning as soon as temperatures begin to warm. Late frosts usually occur on clear nights, which means the next morning is typically bright and sunny. Under direct sun, temperatures under frost covers can build quickly, resulting in heat damage to new growth. Yes, going out to drape sheets over plants each evening and then removing them the next morning is a pain but like so many things in life, the tried and true is the safest bet.

Worm Juice!

There’s still snow on the ground, but I know that spring is finally coming to Minnesota because I FINALLY saw a crocus peeking its head out of the ground this week!

So perhaps you wonder from time to time what garden professor types get excited about. Well, here’s an example. Tomorrow I’ll be meeting up with a friend of mine, Meleah Maynard, which is nice, we always have a good time chatting, but I’m especially excited because she’s bringing me some drippings from her vermicomposting. Hooray, worm juice! I’ll be taking it to the lab and then running some tests on it to see what it has in it in terms of nutrients. After I get the results in a couple of weeks I’ll give you the information (maybe even compare it side by side with urine – that would be fun!)