Toxic mulch: When shredded bark goes bad

We typically think of mulching landscape beds as a good thing.  And it usually is; helping to conserve soil moisture, reducing soil temperatures and contributing to soil organic matter.  Recently, however, I received an e-mail from a local landscaper that reported severe damage to annuals and perennials in a landscape bed immediately after applying hardwood mulch.  The problem, sometimes referred to as ‘sour mulch’ or ‘toxic mulch’, occurs when mulch is left is large piles and undergoes anaerobic conditions.  This results in the production of acids and other compounds that can volatilize when the mulch is placed in beds, especially during hot weather.  These vapors can quickly damage annuals and other sensitive plants.  Mulch in this condition is often characterized by a ‘sour’ smell.  If you suspect your mulch has gone sour, spread it out before use to allow toxins to dissipate and water thoroughly either before or immediately after application.  The University of Arkansas Extension has a nice fact sheet in the subject “Plant injury from ‘sour’ wood mulch.http://www.uaex.edu/Other_Areas/publications/PDF/FSA-6138.pdf


Fried Gerber daisy


Sedums are usually pretty tough…

And, yes, I did steal the title of this post from one of my all-time favorite ‘Far Sides’…

 

Sunday Bloody Sunday

Is this title too extreme?  I’ll leave that up to you.

Most of you are aware of the frog controversy that surrounds Round-up.  A few years ago a professor from Pittsburgh showed that this chemical can kill aquatic creatures if it gets into a pond. Particularly tadpoles.  Not that Round-up is intended to be used around water, but still, it is a concern and I don’t want to minimize it.  Nor do I want people to forget that other supposedly safer products have their own set of dangers.

This past Sunday I was in the back yard pulling weeds (there is the possibility that my post last week led to this fate…but I’m not going to examine that here).  One of the places where I pulled weeds was under the deck at the back of our house.  This area is covered with rock mulch and hasn’t been weeded all year.  I started out pulling the large weeds, which took about 15 minutes, and then I started pulling the smaller weeds.  After another 15 minutes I realized there was no way that I was going to be able to pull all of the small weeds in what I considered a reasonable time.  So I went to the garage where I found a bottle of 20% acetic acid – that super strong weed killing vinegar spray that I’ve mentioned before.  I knew the stuff was too strong and not a great choice — I had been planning to take it in to school and use it for some experiments there, but I figured what the heck, it ought to do some damage to the little weeds, even if it doesn’t completely wipe them out.  So I started spraying.

The first things I noticed were things that I’ve had to cope with before when using this trigger-spray bottle.  The spray misted onto my hand and hit a small cut making further spraying uncomfortable –  but I pressed on (At this point you should all be screaming at me PUT SOME DAMN GLOVES ON – You’re right this was a stupid move on my part) and the smell was almost overwhelming.  But I expected these things, so I figured I’d finish.  Then, out of the corner of my eye I saw something coming from an area that I’d just sprayed — moving across the gravel and approaching fast.  It was a small toad, no doubt there to eat slugs.  He was hopping all over the place with no apparent direction.  Random leaps here and there.  I picked him up – and noticed that his eyes were glazed.  I called for my wife to bring a bowl of water – which she did.  I washed him off, but he had already stopped moving.  A few minutes later it was no better – just random twitches and nothing else.  His eyes seemed covered by a fine film – almost like cataracts.  I put him in a cool moist shady spot hoping that he might get better, but I didn’t have the heart to check on him.  The vinegar did him in.

I kill insects and other critters all the time and I’m no vegetarian — so why should I whine about this little guy?  Because it’s always a shame when a life is lost without a purpose.  This guy was helping me out underneath that deck and I killed him because I made a stupid decision by using a pesticide which I knew was a bad choice.  If I’d used Round-up (which I have accidentally sprayed a small amount of on adult toads without apparent effect)– or better yet taken the time to pull the weeds by hand I would have avoided this whole situation and I could have done a better job killing the weeds too.

Weird Plant Wednesday – II

Okay, so it’s actually Thursday morning. We’re doing a "staycation" this week and my farm work to-do list dwarfs my usual work week. Not exactly relaxing.  One of the daily duties is dragging the hose around trying to keep some favorite plants alive. We’re in a drought, though not near of the awful and epic proportions of some parts of the country.  When our Floriculture Forum was held at the Dallas Arboretum this spring, horticulturist Jimmy Turner welcomed us to "Gardening Hell."  Huh? Everything was lovely, verdant, and smothered in tulips.  But that was February. Bless all your gardening hearts out there (and everywhere else that is so damned dry).

I do get to drag the hose right past one of my favorite garden additions of the last few years. Bulbine frutescens is a South African native that thrives in dry, dry, dry.  USDA Zone 9 or thereabouts on the ol’ hardiness scale. We’ve planted it in our tiny scree garden, where several succulents get to spend the warm season stretching their roots before getting scooped back into a pot to overwinter in a chilly greenhouse.  (And pardon if Bulbine is as common as mud in your part of the world/continent, it’s just not that well known in the eastern part of the U.S.)


Bulbine frutescens ‘Hallmark’.  Looks a bit like my hair this morning.  Yes, it would benefit from some deadheading (the plant, that is).

Bulbine foliage looks a lot like the "grassy" species of aloe, and the juice from the leaves is supposed to have some of the same properties when applied to burns and scrapes. It has a fairly neat habit,  but within the mound of foliage forms lots of rhizomatous clumps. These are perfect for dividing and sharing (despite the genus name, no bulbs are involved).  It flowers non-stop, even throughout most of the winter in the 50 F greenhouse. Our plant is the orange cultivar ‘Hallmark’. The straight species has yellow flowers and can reseed a bit; but I’ve never seen a seedling.


Lovely flowers. No extra water needed – yay!

Podcast #2 – Garden Concoctions

I’m getting my feet under me with podcasting – it’s becoming more fun and less scary.  The theme for this one is “Garden Concoctions,” so the Plants in the News and Myth Busting segments are along those lines.

My interview this week is with Maurice Skagen, owner and designer of Soos Creek Botanical Gardens.  This 23 acre plant collection has been carefully cultivated over the last 30 years and just recently opened to the public.


A volunteer visits with Maurice


Soos Creek draws visitors of all ages


The pond


The long borders


Clematis canopy over trees


Demonstration vegetable garden

Please let me know what you think of the podcast; you can email me directly or post a comment on the blog. Suggestions for future podcasts are most welcome!

Out of the lead frying pan and into the phosphate fire

A recent NYT post reports that adding fish meal to lead-contaminated soils will cause the lead to bind to phosphate found in fish bones.  As the article explains, this chemical reaction results in the formation of pyromorphite, “a crystalline mineral that will not harm anyone even if consumed.”

Given my concerns about excessive phosphate loading in urban soils, I contacted Dr. Rich Koenig, an urban soil scientist and chair of WSU’s Crop and Soil Science department.  I wondered, at least, if the article should have directed people to have a soil test done first to determine how much phosphate was already in the soil before adding more.

Dr. Koenig was likewise concerned that the application rate of fish meal was probably far higher than what plants would require, thus increasing the risk of phosphorus leaching and runoff. He also referred my question to Dr. Jim Harsh, a soil chemist in his department familiar with the process described in the article.

And as Dr. Harsh pointed out, it’s important to make lead less susceptible to uptake by people and other animals exposed to contaminated soils.  However, he’s unconvinced that phosphate is the best choice; in fact, research by Dr. Sally Brown (cited in the NYT article) and others (including Dr. Harsh) have found that compost containing iron is also able to bind and immobilize lead.  The advantage of high iron compost is that iron will not leach into nearby waterways, nor cause the same kinds of plant toxicity problems, as phosphate can.

Thanks to both Dr. Koenig and Dr. Harsh for their quick and informative responses on this topic.

Being Lazy Has Its Advantages

I am just about the laziest gardener you’d ever want to meet.  Around my field plots at the school things tend to look good –but that’s part of my job.  Around my home, well, I probably water my plants once or twice a year, I fertilize every few years.  I almost never use herbicides or any other weed control methods besides pulling – again, that happens once or twice a year.  And I only mulch about once every two years or so (sorry Linda!).  My yard does end up being a great place for my experiments on slugs, weeds, and odd methods of insect control, but it’s far from the pride of the neighborhood.  Generally I plant things and let them either live or fail and just don’t worry about it that much if they can’t make it.  That said, I think that I would fare better if I just accepted weeds as an integral part of my yard.  It has already happened in my lawn.  This year the clover has finally started to take hold.  I’m happy about this because it will mean less fertilizer.  In the back yard I’ve knocked out most of the thistle (hand pulling and a little bit of Round-Up), and now daisies are popping up.  Sometimes they’re in spots where I’d prefer to have a lilac or rose – but hey, they’re not bad.  It almost looks like I planted them on purpose.

My laziness recently however, reached a new level (my wife isn’t particularly pleased about it, but so far the summer has been busy enough that I’ve been able to find lots of excuses).  On our back porch we usually grow some tomatoes or cabbage, or something in a container.  This year we didn’t bother and so the container started to grow weeds.  Specifically purslane.  At first this seemed like a bad thing, but then it started looking … good.  It filled out the container.  It didn’t need any watering, and, by golly, it actually tasted good!  Now tasting random weeds from your backyard (or uncared for container) is not something that I encourage.  And even if you want to taste purslane have an expert (such as a botanist) confirm that it’s purslane before you go chomping on it.  But that said, I tasted this stuff after I found out it was edible and now we have a new leafy veggie for our salads.  Then I started figuring out all of the weeds in the yard, both front and back, that are edible.  I already love clover flowers and I’m OK with young dandelion leaves.  Shoot.  I’m starting to think that if I could take my laziness to yet another level my family and I could eat salad all year without ever buying lettuce at the supermarket.

Weird Plant Wednesday!

Greetings, all!  Things seem to be pretty slow in the blog-reading world…middle of summer, vacations, etc. Plus we’re all out there gardening, unlike the dead of winter when we’re deprived of this joy, so the next best thing seems to be reading about it.  Thanks to all who check in with us, even if just occasionally!

I’m taking over the Wednesday slot for a little while – I have a backlog of cool/weird/new/unusual plants to share, and  Weird Plant Tuesday just doesn’t bring the alliteration.

Our first subject: Aristolochia gigantea – Brazilian Pipestem (or Brazilian Dutchman’s Pipe – bit of a culture-clash ). The genus Aristolochia is chock-full of unusual-looking flowers, but I think this one takes the cake.


This flower is actually upside-down, hanging off a trellis. The lobes are at the base of the flower.

The big, blorpy bud starts out vaguely rude-looking, then opens to a maroon and white-netted beefsteak of a flower.  I do like the National Tropical Botanic Garden’s description that “The back view of the flower superficially resembles a pair of lungs with a canal leading into a stomach-like pouch.”  The perianth/base of the flower is inflated, and the purported pollination strategy is to get flies to enter the “maw” and then hang out in the pouch (“Get in mah belleh, fly!”). Pollen is exchanged in the interim.  Scent is a big part of attracting flies, but I don’t find the fragrance offensive, it’s just a little sweet/off.


Aristolochia gigantea – an open flower from the side (left) and a bud. At Saul’s Nursery re-wholesale yard in Atlanta, Georgia

The vine itself is really vigorous; even with our cooler summer nights here in the Blue Ridge, mine is running amok along the deck railing. The older/larger the vine, the bigger the flowers – I’ve seen some conservatory specimens with two-foot-long flowers. This is, by the way, very tropical. It won’t overwinter in the landscape north of USDA Zone 9. Mine will enjoy a chilly winter in a barely-heated greenhouse; we’ll see how that works out.

How’s that for a start to Weird Plant Wednesday?

Podcasts are here!

Today marks a grand experiment…I’ve made the leap into podcasting. Each episode is less than 30 minutes and contains (among other things) an outdoor interview with someone who does something interesting with gardens and landscapes. This week’s podcast features Seattle landscape designer Richard Greenberg, who took me on a tour of a garden he’s been working on for 20 years:


Linda with Richard Greenberg

The nice thing about having the blog host the podcasts is that I can include some photos from my interview sites.  Here are some shots of this lovely (but tiny) urban landscape, which features a huge sequoia right in the middle.


Yes, a sequoia in the middle of the garden


Fritillaria, I assume? (Please don’t mock my taxonomic ignorance)


Very cool iris

Please let me know what you think of the podcast; you can email me directly or post a comment on the blog.  Suggestions for future podcasts are most welcome!

This Bud’s for you…

Ask the risk of honing in on Jeff’s turf, I thought I’d pass along this article by former University of Maine associate dean (and apparent Garden Professor wannabe) Katheryn Olmstead.   It seems that Dr. Olmstead’s painstaking research has documented a preference among slugs for domestic beers, particularly Budweiser.  http://bangordailynews.com/2011/07/21/living/garden-slugs-prefer-budweiser-over-foreign-brands/  Like most undergraduate students, it seems slugs prefer domestic swill to more refined imported brews; confirming many suspicions about both slugs and undergrads.  Although we’ll have to wait for the full peer-reviewed article, her scientific method seems sound, including use of replicated plots.  That said, her admitted qualms about being seen purchasing two six-packs in the same week raises doubts about Dr. Olmstead’s eventual rise to the rank of full Garden Professor