The Garden Professors™ – Page 93 – Advancing the science of gardening and other stuff since 2009

Genetic Engineering, Veal, and Rennin

Today I thought I’d go just a little off topic. Lots of people out there are really upset about the idea of putting genes into plants, like putting genes for Round-Up resistance into soybeans, or genes for caterpillar resistance into corn. And, I do agree, this is a pretty powerful technology that needs to be used carefully – probably more carefully than it’s being used right now with plants.

But the funny thing is, one of the places where transgenic creatures really dominate the market is in a place that is almost never considered. Today 80-90% of cheese made in the United States is produced using bacteria genetically engineered to produce rennin. What is rennin you ask? Renin is the stuff normally found in a cow’s stomach which causes milk to curdle – and cheese to be created. For those of you interested in looking into this further look up rennet which is the substance in a cow’s stomach which naturally contains rennin.

After looking around a bit I really can’t find that many people upset about the use of genetically engineered microbes to produce rennin. Actually, some people who are quite sensitive to environmental concerns may prefer it. Historically rennin comes from dead young cows – it’s a byproduct of veal production (kind of a nasty industry if you ask me). Rennin that comes from genetically altered bacteria has nothing to do with dead cows and so vegetarians often find cheese produced with genetically engineered rennin to be more appropriate.

California Flower, Food and Garden Show

I’m giving two talks at the California Flower, Food and Garden Show in Sacramento today and tomorrow: details are linked here. It would be great to meet some of our California readers in person if you plan on being there.

I’ll try to take some photos and share my thoughts about the show on upcoming posts. Maybe I’ll even find my Friday quiz topic lurking there!

Rain barrels

A few weeks ago one of our readers, landscape architect Owen Dell, sent me a link to his blog where he takes on rain barrels. It’s a great analysis of the (im)practicalities of rain barrels and it got me to wondering how many of our readers (and my GP colleagues) use these as supplemental sources of irrigation water?

I have two in our back yard that were made from old olive oil containers retrofitted for collecting and dispensing water. They’re hooked together so that when one fills, the rain is diverted to the second.

We use this water pretty much for watering container plants, especially those on our south-facing front porch that require watering every other day during the summer. The barrels each hold 55 gallons and are always full during the winter and spring. We drain them almost dry over the summer, but even a brief rain results in several gallons collected.

So I think they’re a pretty good deal, since we use relatively little water from the hose to keep our container plants happy. But Owen brings up some valid points in his analysis, as do commenters on his blog.

What do you all think?

Mulch much?

[Try to say post title three times fast. Heh.]

Here on the GP blogski, we’ve discussed both the merits and shortcomings of many non-traditional forms of mulch; rather, stuff that covers the ground that is referred to as mulch. Shredded rubber, marble chips, lava stone, dyed lava stone (ick), etc.

But this is a new one on me:

Naturally, I immediately shoved my hand in the biggest tub of glass (part of the Scientific Method). It was not…super smooth. A couple of pieces stuck, and there was a bit of sparkly-dust residue. I tried to remember not to rub my eyes for the rest of the day. Not sure I’m buying the recommendation to “use in pathways.”

"Aaargh! My Eyes!"

Pretty colors…soooo shiny. And recycled!

What’s this? A warning label on the aqua mulch: “Parents, please watch your children’s hands around the glass mulch.”Whoops.

April foolery revisited

You certainly had fun with this! Yes, it’s “lucky bamboo,” a name which is completely inappropriate given that it’s not bamboo (but Dracaena sanderiana) and it’s certainly not lucky:

Now “spiral lucky bamboo” is usually dracaena (or as I like to call it “not-bamboo”) that’s been exposed to a unidirectional light source and turned at intervals to create a contorted spiral shape:

These plants, on the other hand, have been cut into straight sections and bound with shiny gold wire in ever increasing lengths so that we have a leaning tower of not-bamboo surrounded by adulating ceramic frogs (good eyes Anne and Jam!). Given enough time – a few weeks, maybe – whatever architectural appeal this arrangement had will be covered with leafy growth from all those sprouting nodes.

There’s a homework assignment for someone: buy one of these, then film it under time lapse photography. If our tech guys ever get our video capability up on this blog, I’ll post them!

Looking for the lowdown on tree rings

Often we use our blog space as a soapbox from which to pontificate, but today I’m looking for some input from our loyal readers. Last week I received a note from an editor looking for some words about tree rings. We’re talking about landscape tree rings for planting annuals or perennials, not dendrochronology.

The editor was interested in specifics on tree rings for large existing trees such as what type of materials to use, what types of flowers or plants worked best, which trees can or can’t have tree rings, etc. My reply was short, maybe even a little curt, “I don’t have any experience with tree rings but our general recommendation is to avoid grade changes around trees whenever possible. After I sent the reply I started thinking, is there any real harm to tree rings? I’ve seen some that looked pretty nice (seen many that look like crap, too). For most trees the amount of surface area covered is small compared to total surface root area. If care is taken not to bury the root collar and trunk, would the tree notice covering a little bit of mostly structural roots? Would appreciate thoughts (pro and con) from those with direct experience.

April foolery

Let’s see if anyone can figure out what this is:

What’s the plant, and what in the world has been done to it?

Answer Monday!

Are Pretty Flowers Useful?

Yesterday I had the opportunity to listen to Marla Spivak, a very highly regarded bee scientist, talk about how bees defend themselves from disease. Very interesting stuff. I took a lot of information away from the talk, two bits of which I want to share with you.

The first is a vocabulary word — propolis – go ahead, google it (I don’t think too much inappropriate stuff will pop up) – it’s an antimicrobial “ointment” which bees create from stuff like the resins on tree buds.

The second is that the number of bee colonies is the US has been going down in the US since 1945 for a number of reasons. One of the most important of which is the fact that we like to kill flowers, such as dandelions and clover, which bees like, and then we plant crappy flowers – at least as far as the bees are concerned. The whole crappy flower thing isn’t something that I’d spent much time thinking about, so it was kind of an ah-ha moment for me.

Here’s how it works. People tend to like double flowers. Double flowers usually occur because the male parts of the flowers – the parts which normally contain pollen – instead develop into petals. It’s a mutation – very pretty – but it inhibits the flower from reproducing itself through seed and it certainly isn’t great for bees who rely on pollen for food. So when we plant our gardens we are removing plants that bees may love because we consider them weeds. Then we replace these flowers with what amounts to plastic fruit. My opinion – this is probably more significant to the lives of both honey bees and native bees than whether we plant natives or exotics.

So let your yard go wild! The bees will thank you.

Is “lasagna gardening” really worth the effort?

This week I got a complimentary copy of Urban Farm, dedicated to “sustainable city living.” The cover story is Lasagna Giardino – follow this recipe for a lasagna garden that grows perfect plants – Italian or not.

This is not a new idea, but was popularized several years ago as a way of preparing soil for planting. The article relates the steps:

1) Prepare the ground by mowing the lawn
2) Dig up the first 12″ of soil (double digging)
3) Place a layer of “noodles” (paper and cardboard are popular) – the low nutrient material
4) Place a layer of “sauce” (the green material)
5) Repeat as often as you like and “let it cook”

I like the first step of this. But my second step would be:
2) Add a thick layer (12″) of arborist wood chips and “let it cook.”

Double digging the soil 12″ isn’t necessary: we do it because it’s hard work, and we think we need to put elbow grease into the project. Making layers of noodles and sauce isn’t necessary: we do it because appeals to us -lasagna is a tasty comfort food.

There’s a lot of damage that this “recipe” can cause. Double digging the soil 12″ destroys soils structure. Don’t do it. The layers of noodles and sauce (especially the sauce) can create an overload of plant nutrients. Furthermore, the “noodle” layers – the sheet mulches – impede water and air movement. They’re not needed to keep the grass from growing through. Wood chips do this just fine on their own. And don’t worry about that initial 12″ of chips. Within a few weeks it will settle to about 8″. Let it sit for several weeks. Then pull aside some of the chips and take a look. If the process is done, the grass and/or weeds will be dead and decomposing – a natural compost layer. You can then plant whatever you like. Reuse the chips somewhere else in your garden.

It doesn’t look like lasagna, but it’s a heck of a lot easier and more closely mimics a natural mulch layer than lasagna does.

It’s Spring-o’clock Somewhere…

We’re supposed to get an inch or two of snow tomorrow. It was 75 degrees last week. Typical schizophrenic spring weather. But spring was already in full bloom a few weeks ago in Dallas, Texas. Our group of Virginia Tech floriculture faculty and grad students visited for the National Floriculture Forum, a meeting of researchers and educators. It was organized by Texas A&M and hosted by the Dallas Arboretum, home of uber-horticulturist Jimmy Turner.

The Arb was right in the middle of their “Dallas Blooms” festival – they plant half a million spring bulbs each year for the most amazing show this side of Keukenhof. I’ve never been a huge tulip fan, but somehow came back with a gazillion photos. You just couldn’t help it. It’s a beautiful display garden; don’t miss it if in the area.

Imagine 60+ acres of this. My retinas were burning. But in a good way.

A cute Fosteriana-type tulip, oddly named ‘Zombie’.
Note the use of pecan hulls as mulch. Results in the biggest, fattest squirrels you’ve ever seen.

I’ve seen some interesting art in public gardens, but this is a new fave.
Probably there’s a deeper meaning behind it, but basically it’s a man and woman snogging in the tulips.

Big squirting toads, with list of safety rules on what one shouldn’t do to/with the toad.

Jimmy said the place would be crawling with brides and babies by afternoon, and he was right. That’s what he gets for creating such a photogenic garden. Couldn’t swing a fat squirrel without hitting one or the other.